Additive Manufactoring - Contributi utente [it]

Impact of additive manufacturing on engineering education

2020-01-08T19:06:37Z

LuciaBianchettina:

'''Title:''' Impact of additive manufacturing on engineering education (Politecnico di Torino, Italy)

'''Authors:''' Paolo Minetola , Luca Iuliano , Elena Bassoli , Andrea Gatto''

'''Keywords:''' Advanced manufacturing technologies, Rapid manufacturing, Product design, Manufacturing technology, Computer aided modelling, Computer aided manufacturing.

'''Purpose:''' The purpose of this paper is to evaluate how the direct access to additive manufacturing (AM) systems impacts on education of future mechanical engineers, within a Master’s program at a top Italian University.

'''Methodology:''' A survey is specifically designed to assess the relevance of entry-level AM within the learning environment, as a tool for project development. The survey is distributed anonymously to three consecutive cohorts of students who attended the course of “computer-aided production (CAP)”, within the Master of Science Degree in Mechanical Engineering at Politecnico di Torino. The course includes a practical project, consisting in the design of a polymeric product with multiple components and ending with the production of an assembled prototype. The working assembly is fabricated by the students themselves, who operate a fused deposition modelling (FDM) machine, finish the parts and evaluate assemblability and functionality. The post-course survey covers diverse aspects of the learning process, such as: motivation, knowledge acquisition, new abilities and team-working skills. Responses are analyzed to evaluate students’ perception of the usefulness of additive technologies in learning product design and development. Among the projects, one representative case study is selected and discussed.

'''Limitations:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Findings:''' Results of the research affirm a positive relationship of access to AM devices to perceived interest, motivation and ease of learning of mechanical engineering. Entry-level additive technologies offer a hands-on experience within academia, fostering the acquisition of technical knowledge.

'''Practical implications:''' Early exposure of forthcoming designers to AM tools can turn into a “think-additive” approach to product design, that is a groundbreaking conception of geometries and product functionalities, leading to the full exploitation of the possibilities offered by additive technologies.

'''Originality/value:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Grafical Abstract:''' [[File:img1.png|centro|miniatura]]

'''Full reference:''' Minetola, P., Iuliano, L., Bassoli, E., & Gatto, A. (2015). Impact of additive manufacturing on engineering education–evidence from Italy. Rapid Prototyping Journal, 21(5), 535-555.

'''Link:''' https://www.emerald.com/insight/content/doi/10.1108/RPJ-09-2014-0123/full/html#idm45947990859216

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T19:05:10Z

LuciaBianchettina:

'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying

'''Authors:''' Rocco Lupoi, ShuoYin, XingchenYan, ChaoyueChen, RichardJenkins, MinLiu''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[File:img2.jpg|centro|miniatura]]
'''Full reference:''' Yin, S., Yan, X., Chen, C., Jenkins, R., Liu, M., & Lupoi, R. (2018). Produzione di additivi ibridi di materiali funzionalmente classificati Al-Ti6Al4V con fusione laser selettiva e spruzzatura a freddo. Journal of Materials Processing Technology , 255 , 650-655.

'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T19:04:44Z

LuciaBianchettina:

'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying

'''Authors:''' Rocco Lupoi, ShuoYin, XingchenYan, ChaoyueChen, RichardJenkins, MinLiu''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[File:img2.jpg|centro|miniatura]]
'''Full reference:''' Yin, S., Yan, X., Chen, C., Jenkins, R., Liu, M., & Lupoi, R. (2018). Produzione di additivi ibridi di materiali funzionalmente classificati Al-Ti6Al4V con fusione laser selettiva e spruzzatura a freddo. Journal of Materials Processing Technology , 255 , 650-655.
'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Hybrid Additive Manufacturing

2020-01-08T19:01:28Z

LuciaBianchettina:

*[[Hybrid Additive Manufacturing SLM-CS]]

Hybrid Additive Manufacturing SLM-CS

2020-01-08T19:01:09Z

LuciaBianchettina: Creata pagina con "*Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS"

*[[Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS]]

Hybrid Additive Manufacturing

2020-01-08T19:00:30Z

LuciaBianchettina:

*[[Hybrid Additive Manufacturing SLM]]
*[[Hybrid Additive Manufacturing SLM-CS]]

Hybrid Additive Manufacturing

2020-01-08T18:59:44Z

LuciaBianchettina:

*[[Hybrid Additive Manufacturing SLM-CS]]

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

2020-01-08T18:58:56Z

LuciaBianchettina:

'''Title:''' Development of a multifunctional panel for aerospace use through SLM additive manufacturing

'''Authors:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varettib, Paolo Maggiore, Andrea Mazza''

'''Keywords:''' DOE, Metamodeling, Pareto optimality, Virtual protyping, Response surface, Additive manufacturing.

'''Abstract:''' Lattice materials can overcome the need of light and stiff structures in the aerospace industry. The wing leading edge is oneof the most critical parts for both on-board subsystem and structure features: it must withstand to the aerodynamicloads and bird-strike, integrating also the anti-ice system functions. Nowadays, this part is made by different components bonded together such as external skin, internal passageways, and feeding tubes. In the present work, a single-piece multifunctional panel made by additive manufacturing will be developed.

'''Purpose:''' This work traces the development of a novel system of anti-ice, directly integrated inside the primary structure. This new-patented system uses a lattice core as a heat exchanger, as reported schematically in Fig.1.Using this sandwichis possible to obtain a light and stiff structure with a great internal thermal exchange surface. Selective Laser Melting (SLM) and Electron Beam Melting (EBM) can realize non-stochastic structures with controlled porosity.

'''Methodology:''' To establish whether of the design variable affects majorly the mechanical resistance of the sandwich panel, a Design of Experiment (DOE) has been designed. DOE method has been applied through FEM simulations on a NACA profile, using real loads from aerodynamic simulations. FEM model considers the outer skins modelled as shells and the lattice core made by beams. So that, DOE design variables considered in the present work are: cell type, cell length, beam section radius, shell thickness. FEM geometry (cell type and length) was set-up through a MATLAB code designed for automatize the FEM pre-processing.

'''Limitations:''' Due to practical constraint, this paper provide a limatatedview of all the aero-elastic behaviour.

'''Benefits:''' The adopted DOE allowed to build a full quadratic response surface that was used to optimize mass and frequency, leaving the maximum stresses under a threshold safe for yielding.

'''Full reference:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varetti, Paolo Maggiore, Andrea Mazza, Development of a multifunctional panel for aerospace use through SLM additive manufacturing, ''Procedia CIRP'', Volume 67,2018, Pages 215-220.

'''Link:''' https://reader.elsevier.com/reader/sd/pii/S2212827117311460

Aerospace

2020-01-08T18:57:28Z

LuciaBianchettina: Creata pagina con "*Development of a multifunctional panel for aerospace use through SLM additive manufacturing"

*[[Development of a multifunctional panel for aerospace use through SLM additive manufacturing]]

Main Page

2020-01-08T18:57:14Z

LuciaBianchettina: /* Parts */

[https://docs.google.com/document/d/1Dpv8YCcSNuxh99Nw9ARPFtaRnw1ZEKm8RlWba0UMcWU/edit Istruzioni (in Italian, sorry)]

=[[Materials]]=

[[Additive Manufacturing Approaches for Hydroxyapatite‐Reinforced Composites]]

[[Precision additive manufacturing of NiTi parts using micro direct metal deposition]]

=[[Processes]]=
*[[Fused Deposition Modeling]]
*[[Wire Arc Additive Manifacturing]]
*[[Material Jetting]]
*[[Vat Polymerization]]
*[[Selective Laser Melting]]
*[[Hybrid Additive Manufacturing]]
*[[Laser engineered net shaping]]
*[[Droplet-Based Manufacturing]]
*[[Laser Processing]]
*[[3D printing benefits on supply chain]]
*[[Augmented reality 3D for manual assemply workstation]]

=[[Parts]]=
*[[Selective Laser Melting Parts]]
*[[3D printing for health & wealth: Fabrication of custom-made medical devices through additive manufacturing.]]

Selective Laser Melting Parts

2020-01-08T18:55:59Z

LuciaBianchettina:

* [[Design for AM for Selective Laser Melting ]]
* [[Aerospace]]

Impact of additive manufacturing on engineering education

2020-01-08T17:41:14Z

LuciaBianchettina:

'''Title:''' Impact of additive manufacturing on engineering education (Politecnico di Torino, Italy)

'''Authors:''' Paolo Minetola , Luca Iuliano , Elena Bassoli , Andrea Gatto''

'''Keywords:''' Advanced manufacturing technologies, Rapid manufacturing, Product design, Manufacturing technology, Computer aided modelling, Computer aided manufacturing.

'''Purpose:''' The purpose of this paper is to evaluate how the direct access to additive manufacturing (AM) systems impacts on education of future mechanical engineers, within a Master’s program at a top Italian University.

'''Methodology:''' A survey is specifically designed to assess the relevance of entry-level AM within the learning environment, as a tool for project development. The survey is distributed anonymously to three consecutive cohorts of students who attended the course of “computer-aided production (CAP)”, within the Master of Science Degree in Mechanical Engineering at Politecnico di Torino. The course includes a practical project, consisting in the design of a polymeric product with multiple components and ending with the production of an assembled prototype. The working assembly is fabricated by the students themselves, who operate a fused deposition modelling (FDM) machine, finish the parts and evaluate assemblability and functionality. The post-course survey covers diverse aspects of the learning process, such as: motivation, knowledge acquisition, new abilities and team-working skills. Responses are analyzed to evaluate students’ perception of the usefulness of additive technologies in learning product design and development. Among the projects, one representative case study is selected and discussed.

'''Limitations:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Findings:''' Results of the research affirm a positive relationship of access to AM devices to perceived interest, motivation and ease of learning of mechanical engineering. Entry-level additive technologies offer a hands-on experience within academia, fostering the acquisition of technical knowledge.

'''Practical implications:''' Early exposure of forthcoming designers to AM tools can turn into a “think-additive” approach to product design, that is a groundbreaking conception of geometries and product functionalities, leading to the full exploitation of the possibilities offered by additive technologies.

'''Originality/value:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Grafical Abstract:''' [[File:img1.png|centro|miniatura]]

'''Full reference:''' Alexander, P. , Allen, S. and Dutta, D. (1998), “Part orientation and build cost determination in layered manufacturing”, Computer-Aided Design , Vol. 30 No. 5, pp. 343-356
Armillotta, A. (2006), “Assessment of surface quality on textured FDM prototypes”, Rapid Prototyping Journal , Vol. 12 No. 1, pp. 35-41. [ecc]

'''Link:''' https://www.emerald.com/insight/content/doi/10.1108/RPJ-09-2014-0123/full/html#idm45947990859216

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

2020-01-08T17:38:36Z

LuciaBianchettina:

'''Title:''' Development of a multifunctional panel for aerospace use through SLM additive manufacturing

'''Authors:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varettib, Paolo Maggiore, Andrea Mazza''

'''Keywords:''' DOE, Metamodeling, Pareto optimality, Virtual protyping, Response surface, Additive manufacturing.

'''Abstract:''' Lattice materials can overcome the need of light and stiff structures in the aerospace industry. The wing leading edge is oneof the most critical parts for both on-board subsystem and structure features: it must withstand to the aerodynamicloads and bird-strike, integrating also the anti-ice system functions. Nowadays, this part is made by different components bonded together such as external skin, internal passageways, and feeding tubes. In the present work, a single-piece multifunctional panel made by additive manufacturing will be developed.

'''Purpose:''' This work traces the development of a novel system of anti-ice, directly integrated inside the primary structure. This new-patented system uses a lattice core as a heat exchanger, as reported schematically in Fig.1.Using this sandwichis possible to obtain a light and stiff structure with a great internal thermal exchange surface. Selective Laser Melting (SLM) and Electron Beam Melting (EBM) can realize non-stochastic structures with controlled porosity.

'''Methodology:''' In this paper, an innovative solution for a multifunctional sandwich panel was investigated. It consists with a core made by lattice structure and two outer skins, manufactured by additive manufacturing. Aerodynamic loads wereinvestigated by Xfoil and applied to derive simplified FEM models. They wereused to understand how cell geometry and structural elements size may affect stress-strain distribution. The analysis was made according to a Central Composite Design (CCD) that analyze beam radius of the lattice core and shell thickness of the outer layers on two different cell types (cell_1 with 12 beams per cell unit and cell_2 with 8) and length (7 mm or 5 mm). Responses investigated maximum stress distribution, total displacement, massand 1stmode frequency as derived from Optistruct FEM analysis. At the end of the analysis campaign, a real demonstrator will be build and tested in a wind tunnel facility with temperature and humidity controls to verify the effectiveness of the patented system.

'''Limitations:''' Due to practical constraint, this paper cannot provide a comprehensive view of all the aero-elastic behaviour but is intended to provide new insights for further development.

'''Benefits:''' The adopted DOE allowed to build a full quadratic response surface that was used to optimize mass and frequency, leaving the maximum stresses under a threshold safe for yielding.

'''Full reference:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varetti, Paolo Maggiore, Andrea Mazza, Development of a multifunctional panel for aerospace use through SLM additive manufacturing, ''Procedia CIRP'', Volume 67,2018, Pages 215-220.

'''Link:''' https://reader.elsevier.com/reader/sd/pii/S2212827117311460

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

2020-01-08T17:35:52Z

LuciaBianchettina:

'''Title:''' Development of a multifunctional panel for aerospace use through SLM additive manufacturing

'''Authors:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varettib, Paolo Maggiore, Andrea Mazza''

'''Keywords:''' DOE, Metamodeling, Pareto optimality, Virtual protyping, Response surface, Additive manufacturing.

'''Abstract:''' Lattice materials can overcome the need of light and stiff structures in the aerospace industry. The wing leading edge is oneof the most critical parts for both on-board subsystem and structure features: it must withstand to the aerodynamicloads and bird-strike, integrating also the anti-ice system functions. Nowadays, this part is made by different components bonded together such as external skin, internal passageways, and feeding tubes. In the present work, a single-piece multifunctional panel made by additive manufacturing will be developed.

'''Purpose:''' This work traces the development of a novel system of anti-ice, directly integrated inside the primary structure. This new-patented system uses a lattice core as a heat exchanger, as reported schematically in Fig.1.Using this sandwichis possible to obtain a light and stiff structure with a great internal thermal exchange surface. Although this novel solution should be complicated to be constructed and tested with traditional technologies, it is easy to be manufactured in a single-piecewith Additive Manufacturing technology. In fact, Selective Laser Melting (SLM) and Electron Beam Melting (EBM) can realize non-stochastic structures with controlled porosity.

'''Methodology:''' In this paper, an innovative solution for a multifunctional sandwich panel was investigated. It consists with a core made by lattice structure and two outer skins, manufactured by additive manufacturing. Aerodynamic loads wereinvestigated by Xfoil and applied to derive simplified FEM models. They wereused to understand how cell geometry and structural elements size may affect stress-strain distribution. The analysis was made according to a Central Composite Design (CCD) that analyze beam radius of the lattice core and shell thickness of the outer layers on two different cell types (cell_1 with 12 beams per cell unit and cell_2 with 8) and length (7 mm or 5 mm). Responses investigated maximum stress distribution, total displacement, massand 1stmode frequency as derived from Optistruct FEM analysis. At the end of the analysis campaign, a real demonstrator will be build and tested in a wind tunnel facility with temperature and humidity controls to verify the effectiveness of the patented system.

'''Limitations:''' Due to practical constraint, this paper cannot provide a comprehensive view of all the aero-elastic behaviour but is intended to provide new insights for further development.

'''Benefits:''' The adopted DOE allowed to build a full quadratic response surface that was used to optimize mass and frequency, leaving the maximum stresses under a threshold safe for yielding.

'''Full reference:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varetti, Paolo Maggiore, Andrea Mazza, Development of a multifunctional panel for aerospace use through SLM additive manufacturing, ''Procedia CIRP'', Volume 67,2018, Pages 215-220.

'''Link:''' https://reader.elsevier.com/reader/sd/pii/S2212827117311460

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T17:28:11Z

LuciaBianchettina:

'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying

'''Authors:''' Rocco Lupoi, ShuoYin, XingchenYan, ChaoyueChen, RichardJenkins, MinLiu''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[File:img2.jpg|centro|miniatura]]
'''Full reference:''' H. Assadi, H. Kreye, F. Gärtner, T. Klassen Cold spraying – A materials perspective,
G. Bae, S. Kumar, S. Yoon, K. Kang, H. Na, H.J. Kim, C. LeeBonding Features and associated mechanisms in kinetic sprayed titanium coatings, V. Champagne [ecc]

'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Hybrid Additive Manufacturing SLM

2020-01-08T17:23:37Z

LuciaBianchettina: Creata pagina con "*Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS"

*[[Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS]]

Hybrid Additive Manufacturing

2020-01-08T17:23:25Z

LuciaBianchettina:

*[[Hybrid Additive Manufacturing SLM]]

Hybrid Additive Manufacturing

2020-01-08T17:18:16Z

LuciaBianchettina:

*[[Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS]]]

Hybrid Additive Manufacturing

2020-01-08T17:17:28Z

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2020-01-08T17:17:12Z

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[[Hybrid Additive Manufacturing]]

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2020-01-08T17:16:29Z

LuciaBianchettina: /* Literature about AM */

=[[Materials]]=

[[Additive Manufacturing Approaches for Hydroxyapatite‐Reinforced Composites]]

=[[Processes]]=
*[[Fused Deposition Modeling]]
*[[Wire Arc Additive Manifacturing]]
*[[Laser Machining]]
*[[Material Jetting]]
*[[Vat Polymerization]]
*[[Selective Laser Melting]]
*[[Hybrid Additive Manufacturing]]
*[[Cutting Forces Additive Manifacturing]]

=[[Parts]]=
*[[Selective Laser Melting Parts]]
*[[Development of a multifunctional panel for aerospace use through SLM additive manufacturing]]
*[[3D printing for health & wealth: Fabrication of custom-made medical devices through additive manufacturing.]]

Education

2020-01-08T17:16:08Z

LuciaBianchettina: Creata pagina con "*Impact of additive manufacturing on engineering education"

*[[Impact of additive manufacturing on engineering education]]

Fused Deposition Modeling

2020-01-08T17:15:08Z

LuciaBianchettina:

[[Design for manufacturing of surfaces to improve accuracy]]

[[Education]]

Fused Deposition Modeling

2020-01-08T17:14:37Z

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[[Design for manufacturing of surfaces to improve accuracy]]
[[Education]]

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2020-01-08T17:12:59Z

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Impact of additive manufacturing on engineering education

2020-01-08T14:09:19Z

LuciaBianchettina: Creata pagina con "'''Title:''' Impact of additive manufacturing on engineering education (Politecnico di Torino, Italy) '''Authors and full affiliations:''' Minetola , Luca Iuliano , Elena..."

'''Title:''' Impact of additive manufacturing on engineering education (Politecnico di Torino, Italy)

'''Authors and full affiliations:''' Minetola , Luca Iuliano , Elena Bassoli , Andrea Gatto''

'''Keywords:''' Advanced manufacturing technologies, Rapid manufacturing, Product design, Manufacturing technology, Computer aided modelling, Computer aided manufacturing.

'''Purpose:''' The purpose of this paper is to evaluate how the direct access to additive manufacturing (AM) systems impacts on education of future mechanical engineers, within a Master’s program at a top Italian University.

'''Methodology:''' A survey is specifically designed to assess the relevance of entry-level AM within the learning environment, as a tool for project development. The survey is distributed anonymously to three consecutive cohorts of students who attended the course of “computer-aided production (CAP)”, within the Master of Science Degree in Mechanical Engineering at Politecnico di Torino. The course includes a practical project, consisting in the design of a polymeric product with multiple components and ending with the production of an assembled prototype. The working assembly is fabricated by the students themselves, who operate a fused deposition modelling (FDM) machine, finish the parts and evaluate assemblability and functionality. The post-course survey covers diverse aspects of the learning process, such as: motivation, knowledge acquisition, new abilities and team-working skills. Responses are analyzed to evaluate students’ perception of the usefulness of additive technologies in learning product design and development. Among the projects, one representative case study is selected and discussed.

'''Limitations:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Findings:''' Results of the research affirm a positive relationship of access to AM devices to perceived interest, motivation and ease of learning of mechanical engineering. Entry-level additive technologies offer a hands-on experience within academia, fostering the acquisition of technical knowledge.

'''Practical implications:''' Early exposure of forthcoming designers to AM tools can turn into a “think-additive” approach to product design, that is a groundbreaking conception of geometries and product functionalities, leading to the full exploitation of the possibilities offered by additive technologies.

'''Originality/value:''' The advantages of adopting AM technologies at different levels of education, for diverse educational purposes and disciplines, are well assessed in the literature. The innovative aspect of this paper is that the impact of AM is evaluated through a feedback coming directly from mechanical engineering students.

'''Grafical Abstract:''' [[File:img1.png|centro|miniatura]]

'''Full reference:''' Alexander, P. , Allen, S. and Dutta, D. (1998), “Part orientation and build cost determination in layered manufacturing”, Computer-Aided Design , Vol. 30 No. 5, pp. 343-356
Armillotta, A. (2006), “Assessment of surface quality on textured FDM prototypes”, Rapid Prototyping Journal , Vol. 12 No. 1, pp. 35-41. [ecc]

'''Link:''' https://www.emerald.com/insight/content/doi/10.1108/RPJ-09-2014-0123/full/html#idm45947990859216

File:Img1.png

2020-01-08T14:08:38Z

LuciaBianchettina:

Main Page

2020-01-08T14:01:59Z

LuciaBianchettina:

=[[Materials]]=
=[[Processes]]=
*[[Fused Deposition Modeling]]
*[[Laser Machining]]
*[[Material Jetting]]
*[[Vat Polymerization]]
*[[Selective Laser Melting]]
*[[Hybrid Additive Manufacturing]]

=[[Parts]]=
*[[Design for AM]]
*[[Components made AM]]

=[[Literature about AM]]=
*[[Impact of additive manufacturing on engineering education]]

[[Speciale:CreaUtenza]]

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

2020-01-08T13:59:30Z

LuciaBianchettina:

'''Title:''' Development of a multifunctional panel for aerospace use through SLM additive manufacturing

'''Authors and full affiliations:''' Michele Bici, Salvatore Brischetto, Francesca Campana, Carlo Giovanni Ferro, Carlo Seclì, Sara Varettib, Paolo Maggiore, Andrea Mazza''

'''Keywords:''' DOE, Metamodeling, Pareto optimality, Virtual protyping, Response surface, Additive manufacturing.

'''Abstract:''' Lattice materials can overcome the need of light and stiff structures in the aerospace industry. The wing leading edge is oneof the most critical parts for both on-board subsystem and structure features: it must withstand to the aerodynamicloads and bird-strike, integrating also the anti-ice system functions. Nowadays, this part is made by different components bonded together such as external skin, internal passageways, and feeding tubes. In the present work, a single-piece multifunctional panel made by additive manufacturing will be developed. Optimal design and manufacturing are discussed according to technological constraints, aeronautical performances and sustainability.

'''Purpose:''' This work traces the development of a novel system of anti-ice, directly integrated inside the primary structure. This new-patented system uses a lattice core as a heat exchanger, as reported schematically in Fig.1.Using this sandwichis possible to obtain a light and stiff structure with a great internal thermal exchange surface. Although this novel solution should be complicated to be constructed and tested with traditional technologies, it is easy to be manufactured in a single-piecewith Additive Manufacturing technology. In fact, Selective Laser Melting (SLM) and Electron Beam Melting (EBM) can realize non-stochastic structures with controlled porosity. Thespecific objective of this paper is to test different modelsof cells type and different skin thicknesses to understand which design variable affect mainly the mechanical behaviour.

'''Methodology:''' In this paper, an innovative solution for a multifunctional sandwich panel was investigated. It consists with a core made by lattice structure and two outer skins, manufactured by additive manufacturing. Aerodynamic loads wereinvestigated by Xfoil and applied to derive simplified FEM models. They wereused to understand how cell geometry and structural elements size may affect stress-strain distribution. The analysis was made according to a Central Composite Design (CCD) that analyze beam radius of the lattice core and shell thickness of the outer layers on two different cell types (cell_1 with 12 beams per cell unit and cell_2 with 8) and length (7 mm or 5 mm). Responses investigated maximum stress distribution, total displacement, massand 1stmode frequency as derived from Optistruct FEM analysis. Beam and shell stresses of cell_1 are higher than that of cell_2 due to a stiffer structure, and comparable resultsare achieved passing from length_7 to length_5. On stresses, beam radius has the most relevant influence, that in the range decreases non-linearly. Shell thickness has minor effects, parabolic in the range. Only frequency of the 1stmode has interaction effects between beam radius and shell thickness. The adopted DOE allowed to build a full quadratic response surface that was used to optimize mass and frequency, leaving the maximum stresses under a threshold safe for yielding. From the Pareto frontier of the problem, optimal solutions were evaluated. To optimise mass and 1stfrequency beam radius can be set between 0.35 and 0.40 passing from cell_1 to cell_2_ in case of length_5, from 0.47 to 0.50 in case of length_7. Shell thickness, with the same type of progression, changed from 0.52 to 0.40.In the next future,a multi-disciplinaryoptimization of the lattice core will be introduced using extensive CFD methods and lumped parameters to evaluate not only the mechanical behaviours but also the thermal dynamic properties during exercise and under deformations.At the end of the analysis campaign, a real demonstrator will be build and tested in a wind tunnel facility with temperature and humidity controls to verify the effectiveness of the patented system.

'''Limitations:''' Due to practical constraint, this paper cannot provide a comprehensive view of all the aero-elastic behaviour but is intended to provide new insights for further development.

'''Full reference:''' [1] Federal Aviation Administration. Aircraft Icing Handbook. FAA, 1991.[2] Cao Y., Wu Z., Su Y. and Xu Z.Aircraft flight characteristics in icing conditions. Progress in Aerospace Sciences, 2015, Vol. 74, pp. 62-80.[3] XinL., JunqiangB., JunH., KunW.and Yang Z. A spongy icing model for aircraft icing.Chinese Journal of Aeronautics, 2014, Vol. 27, pp. 40-51.

'''Link:''' https://reader.elsevier.com/reader/sd/pii/S2212827117311460

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

2020-01-08T13:59:04Z

LuciaBianchettina: Creata pagina con "'''Title:''' Development of a multifunctional panel for aerospace use through SLM additive manufacturing '''Authors and full affiliations:''' Michele Bici, Salvatore Brische..."

Components made AM

2020-01-08T13:50:48Z

LuciaBianchettina: Creata pagina con "*Development of a multifunctional panel for aerospace use through SLM additive manufacturing"

*[[Development of a multifunctional panel for aerospace use through SLM additive manufacturing]]

Main Page

2020-01-08T13:50:23Z

LuciaBianchettina: /* Parts */

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T13:46:10Z

LuciaBianchettina:

'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying

'''Authors and full affiliations:''' RoccoLupoi, , ShuoYin, XingchenYan, ChaoyueChen, RichardJenkins, MinLiu''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[File:img2.jpg|centro|miniatura]]
'''Full reference:''' H. Assadi, H. Kreye, F. Gärtner, T. Klassen Cold spraying – A materials perspective,
G. Bae, S. Kumar, S. Yoon, K. Kang, H. Na, H.J. Kim, C. LeeBonding Features and associated mechanisms in kinetic sprayed titanium coatings, V. Champagne [ecc]

'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T13:45:49Z

LuciaBianchettina:

File:Img2.jpg

2020-01-08T13:44:54Z

LuciaBianchettina:

Design for manufacturing of surfaces to improve accuracy

2020-01-08T12:22:22Z

LuciaBianchettina:

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

2020-01-08T12:21:42Z

LuciaBianchettina: Creata pagina con "'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying '''Authors and full affiliations:'''..."

'''Title:''' Hybrid additive manufacturing of Al-Ti6Al4V functionally graded materials with selective laser melting and cold spraying

'''Authors and full affiliations:''' RoccoLupoi, , ShuoYin, XingchenYan, ChaoyueChen, RichardJenkins, MinLiu''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010]]

'''Full reference:''' H. Assadi, H. Kreye, F. Gärtner, T. Klassen Cold spraying – A materials perspective,
G. Bae, S. Kumar, S. Yoon, K. Kang, H. Na, H.J. Kim, C. LeeBonding Features and associated mechanisms in kinetic sprayed titanium coatings, V. Champagne [ecc]

'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Design for manufacturing of surfaces to improve accuracy

2020-01-08T12:17:57Z

LuciaBianchettina:

'''Title:''' Design for manufacturing of surfaces to improve accuracy in Fused Deposition Modeling

'''Authors and full affiliations:''' Alberto Boschetto, Luana Bottini, ''Department of Mechanical and Aerospace Engineering, University of Rome La Sapienza, Via Eudossiana 18, 00184 Rome, Italy .''

'''Keywords:''' Selective laser melting (SLM), Cold spraying (CS), Functionally graded material (FGM), Additive manufacturing (AM), XRD, Grain microstructure .

'''Abstract:''' A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper. The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS). The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface. The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock. Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

'''Purpose:''' A hybrid AM technology combining SLM and CS is proposed in this work to fabricate metal-metal and metal matrix composite (MMC)-metal FGMs.

'''Methodology:''' For proving the feasibility of this hybrid AM process, a targeted experiment using CS to deposit pure Al and Al + Al2O3 MMC onto SLM Ti6Al4V part was carried out. The reason for choosing Ti6Al4V and Al as the feedstock is: firstly, Ti is non-weldable with Al due to the formation of brittle intermetallic phase (Al3Ti, Al2Ti) and the substantial difference in melting temperature and thermal expansion ratio (Tomashchuk et al., 2015); secondly, dense Ti and Ti6Al4V are difficult to produce with CS due to the high strength-to-weight ratio limiting the plastic deformation of Ti6Al4V particles. In addition, dense Al and Al alloys are hard to produce with SLM due to its high reflectivity (Vo et al., 2013), thereby it is almost impossible to produce an FGM composted of Al and Ti6Al4V with solo CS or SLM technology. In terms of the potential applications of the Al-Ti6Al4V FGM, it could be applied as a structural material in the fields of aerospace and automotive

'''Limitations:''' Despite gaining dense structure, the fabricated FGMs also had some defects. The defect in the SLM Ti6Al4V part was represented by large pores as a result of the accumulation of unmelted particles and surface roughness, while the CS part’s defect was mainly in the form of small pores caused by the insufficient particle plastic deformation. In addition, grain structure study reveals that the SLM Ti6Al4V part exhibited fully acicular martensitic microstructure, in contrast, to α + β microstructure in the feedstock. Therefore, the SLM Ti6Al4V part was slightly harder than the Ti6Al4V feedstock. The grain structure of the CS Al part had no significant change as compared with the Al feedstock, but the hardness of the CS Al part was much higher than that of the Al feedstock due to the work hardening effect. Furthermore, the analysis on the fracture surfaces indicates a high-quality adhesive and cohesive bonding of the FGMs.

'''Findings:''' The hybrid additive manufacturing process effectively prevented the brittle intermetallic phase formation at the connecting interface, producing thick, dense and machinable FGMs composited of non-weldable metals.

'''Practical implications:''' Al alloys and Ti alloys are both widely used as structural materials in aircraft, vehicle and luxury-bike manufacturing. Ti alloys have high strength, while Al alloys are light and low-cost. Therefore, it would be promising if Ti alloys are applied as the core material surrounded by thick Al alloy layer which provides a strengthening effect. Such structural material can provide sufficiently high strength and reduce total weight and material’ cost at the same time. The addition of Al2O3 reinforcements in the outside Al alloy layer will allow a further improvement of the wear-resistance performance. It is worthy to note that the proposed CS-SLM hybrid AM process can be not only used for producing Al-Ti6Al4V FGMs but also suitable for other material combinations and applications. Particularly, based on this hybrid AM process, the CS deposit can be used to modify the original structure of an SLM component by adding new features and also to restore a damaged SLM component.

'''Grafical Abstract:''' [[https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010]]

'''Full reference:''' H. Assadi, H. Kreye, F. Gärtner, T. Klassen Cold spraying – A materials perspective,
G. Bae, S. Kumar, S. Yoon, K. Kang, H. Na, H.J. Kim, C. LeeBonding Features and associated mechanisms in kinetic sprayed titanium coatings, V. Champagne [ecc]

'''Link:''' https://www.sciencedirect.com/science/article/pii/S0924013618300165#sec0010

Hybrid Additive Manufacturing

2020-01-08T12:11:42Z

LuciaBianchettina:

[[Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS]]

Hybrid Additive Manufacturing

2020-01-08T12:10:49Z

LuciaBianchettina: Creata pagina con "Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS"

Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM e CS

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2020-01-08T12:08:59Z

LuciaBianchettina:

Hybrid Adtive Manufacturing

2020-01-08T12:07:43Z

LuciaBianchettina: Creata pagina con "Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM and CS"

[[Hybrid Additive Manufacturing of Al-Ti6Al4V with SLM and CS]]

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2020-01-08T12:05:41Z

LuciaBianchettina: /* Processes */