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Ryan B Wicker - One of the best experts on this subject based on the ideXlab platform.
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Microstructures and Properties for a Superalloy Powder Mixture Processed by Electron Beam Melting
2012Co-Authors: Jennifer Hernandez, Krista Amato, Edwin Martinez, P. W. Shindo, Emmanuel Rodriguez, César A. Terrazas, Ryan B Wicker, Frank Medina, Lawrence E Murr, S. J. LiAbstract:The microstructures and residual hardnesses for solid components of 2-phase TiAl (Ti-48Al-2Nb-2Cr in a / o ) and Inconel 625 (Ni-19Cr-9Mo-4Nb in w / o ) fabricated by electron beam melting (EBM) were compared with a 10:1 blend of TiAl: alloy 625 pre-alloyed powders producing a complex alloy having the composition 48Ti-24Al-9Ni-8Nb-4.5Cr-4Ni (in w / o ). The blended alloy hardness (HV) reached 7.5 GPa in contrast to 1.4 GPa for the Alloy 625 and 4.0 for the 2-phase TiAl alloy. Reticulated mesh samples and stochastic foam samples prepared from the blended alloy by EBM exhibited a Relative Stiffness versus Relative density plotted on a log-log basis consistent with other reference alloys fitted to a straight line with a slope n = 2 for ideal open cellular materials.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: Lawrence E Murr, Patrick W. Shindo, Y X Tian, Krista Amato, Edwin Martinez, Shujun Li, X.y. Cheng, Francisco Medina, Sara M. Gaytan, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily alpha-phase acicular platelets while the mesh and foam structures were characterized by alpha'-martensite with some residual alpha. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced similar to 2 mu m in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness. (C) 2011 Elsevier Ltd. All rights reserved.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: L E Murr, Y X Tian, Krista Amato, P. W. Shindo, X.y. Cheng, Sara M. Gaytan, E Martinez, F Medina, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily α-phase acicular platelets while the mesh and foam structures were characterized by α(')-martensite with some residual α. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced ~2 μm in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness.
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open cellular copper structures fabricated by additive manufacturing using electron beam melting
2011Co-Authors: D A Ramirez, Sara M. Gaytan, Jose L Martinez, B I Machado, L E Murr, Yongming Tian, E Martinez, F Medina, Ryan B WickerAbstract:Cu reticulated mesh and stochastic open cellular foams were fabricated by additive manufacturing using electron beam melting. Fabricated densities ranged from 0.73 g/cm(3) to 6.67 g/cm3. The precursor Cu powder contained Cu(2)O precipitates and the fabricated components contained arrays of Cu(2)O precipitates and interconnected dislocation microstructures having average spacings of similar to 2 mu m, which provide hardness values similar to 75% above commercial Cu products. Plots of Stiffness (Young's modulus) versus density and Relative Stiffness versus Relative density were in very close agreement with the Gibson-Ashby model for open cellular foams. These open cellular structure components exhibit considerable potential for novel, complex, multi-functional electrical and thermal management systems, especially complex, monolithic heat exchange devices. (C) 2011 Elsevier B.V. All rights reserved.
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characterization of ti 6al 4v open cellular foams fabricated by additive manufacturing using electron beam melting
2010Co-Authors: Lawrence E Murr, Edwin Martinez, Francisco Medina, Sara M. Gaytan, Jose L Martinez, D H Hernandez, B I Machado, D A Ramirez, Ryan B WickerAbstract:Abstract Ti–6Al–4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable Stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of Relative Stiffness versus Relative density were in good agreement with the Gibson–Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.
Sara M. Gaytan - One of the best experts on this subject based on the ideXlab platform.
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Effect of Melt Scan Rate on Microstructure and Macrostructure for Electron Beam Melting of Ti-6Al-4V
2012Co-Authors: Karina Puebla, Edwin Martinez, Francisco Medina, Lawrence E Murr, Sara M. Gaytan, Ryan WickerAbstract:Microstructure and variations in porosity in Ti-6Al-4V samples built with electron beam melting (EBM) over a range of melt scan speeds, ranging from 100 mm·s-1 to 1000 mm·s-1 were examined. Microstructure was characterized by refinement of α-phase and transformation to α′-martensite. Light optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to observe these phenomena, while corresponding tensile testing and associated macro and microindentation hardness measurements were used to define the microstructural variations. Relative Stiffness was observed to be linearly log-log related to Relative density, corresponding to ideal porosity associated with open-cellular structures.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: Lawrence E Murr, Patrick W. Shindo, Y X Tian, Krista Amato, Edwin Martinez, Shujun Li, X.y. Cheng, Francisco Medina, Sara M. Gaytan, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily alpha-phase acicular platelets while the mesh and foam structures were characterized by alpha'-martensite with some residual alpha. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced similar to 2 mu m in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness. (C) 2011 Elsevier Ltd. All rights reserved.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: L E Murr, Y X Tian, Krista Amato, P. W. Shindo, X.y. Cheng, Sara M. Gaytan, E Martinez, F Medina, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily α-phase acicular platelets while the mesh and foam structures were characterized by α(')-martensite with some residual α. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced ~2 μm in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness.
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open cellular copper structures fabricated by additive manufacturing using electron beam melting
2011Co-Authors: D A Ramirez, Sara M. Gaytan, Jose L Martinez, B I Machado, L E Murr, Yongming Tian, E Martinez, F Medina, Ryan B WickerAbstract:Cu reticulated mesh and stochastic open cellular foams were fabricated by additive manufacturing using electron beam melting. Fabricated densities ranged from 0.73 g/cm(3) to 6.67 g/cm3. The precursor Cu powder contained Cu(2)O precipitates and the fabricated components contained arrays of Cu(2)O precipitates and interconnected dislocation microstructures having average spacings of similar to 2 mu m, which provide hardness values similar to 75% above commercial Cu products. Plots of Stiffness (Young's modulus) versus density and Relative Stiffness versus Relative density were in very close agreement with the Gibson-Ashby model for open cellular foams. These open cellular structure components exhibit considerable potential for novel, complex, multi-functional electrical and thermal management systems, especially complex, monolithic heat exchange devices. (C) 2011 Elsevier B.V. All rights reserved.
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characterization of ti 6al 4v open cellular foams fabricated by additive manufacturing using electron beam melting
2010Co-Authors: Lawrence E Murr, Edwin Martinez, Francisco Medina, Sara M. Gaytan, Jose L Martinez, D H Hernandez, B I Machado, D A Ramirez, Ryan B WickerAbstract:Abstract Ti–6Al–4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable Stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of Relative Stiffness versus Relative density were in good agreement with the Gibson–Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.
Lawrence E Murr - One of the best experts on this subject based on the ideXlab platform.
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Microstructures and Properties for a Superalloy Powder Mixture Processed by Electron Beam Melting
2012Co-Authors: Jennifer Hernandez, Krista Amato, Edwin Martinez, P. W. Shindo, Emmanuel Rodriguez, César A. Terrazas, Ryan B Wicker, Frank Medina, Lawrence E Murr, S. J. LiAbstract:The microstructures and residual hardnesses for solid components of 2-phase TiAl (Ti-48Al-2Nb-2Cr in a / o ) and Inconel 625 (Ni-19Cr-9Mo-4Nb in w / o ) fabricated by electron beam melting (EBM) were compared with a 10:1 blend of TiAl: alloy 625 pre-alloyed powders producing a complex alloy having the composition 48Ti-24Al-9Ni-8Nb-4.5Cr-4Ni (in w / o ). The blended alloy hardness (HV) reached 7.5 GPa in contrast to 1.4 GPa for the Alloy 625 and 4.0 for the 2-phase TiAl alloy. Reticulated mesh samples and stochastic foam samples prepared from the blended alloy by EBM exhibited a Relative Stiffness versus Relative density plotted on a log-log basis consistent with other reference alloys fitted to a straight line with a slope n = 2 for ideal open cellular materials.
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Effect of Melt Scan Rate on Microstructure and Macrostructure for Electron Beam Melting of Ti-6Al-4V
2012Co-Authors: Karina Puebla, Edwin Martinez, Francisco Medina, Lawrence E Murr, Sara M. Gaytan, Ryan WickerAbstract:Microstructure and variations in porosity in Ti-6Al-4V samples built with electron beam melting (EBM) over a range of melt scan speeds, ranging from 100 mm·s-1 to 1000 mm·s-1 were examined. Microstructure was characterized by refinement of α-phase and transformation to α′-martensite. Light optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to observe these phenomena, while corresponding tensile testing and associated macro and microindentation hardness measurements were used to define the microstructural variations. Relative Stiffness was observed to be linearly log-log related to Relative density, corresponding to ideal porosity associated with open-cellular structures.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: Lawrence E Murr, Patrick W. Shindo, Y X Tian, Krista Amato, Edwin Martinez, Shujun Li, X.y. Cheng, Francisco Medina, Sara M. Gaytan, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily alpha-phase acicular platelets while the mesh and foam structures were characterized by alpha'-martensite with some residual alpha. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced similar to 2 mu m in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness. (C) 2011 Elsevier Ltd. All rights reserved.
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characterization of ti 6al 4v open cellular foams fabricated by additive manufacturing using electron beam melting
2010Co-Authors: Lawrence E Murr, Edwin Martinez, Francisco Medina, Sara M. Gaytan, Jose L Martinez, D H Hernandez, B I Machado, D A Ramirez, Ryan B WickerAbstract:Abstract Ti–6Al–4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable Stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of Relative Stiffness versus Relative density were in good agreement with the Gibson–Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.
Edwin Martinez - One of the best experts on this subject based on the ideXlab platform.
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Microstructures and Properties for a Superalloy Powder Mixture Processed by Electron Beam Melting
2012Co-Authors: Jennifer Hernandez, Krista Amato, Edwin Martinez, P. W. Shindo, Emmanuel Rodriguez, César A. Terrazas, Ryan B Wicker, Frank Medina, Lawrence E Murr, S. J. LiAbstract:The microstructures and residual hardnesses for solid components of 2-phase TiAl (Ti-48Al-2Nb-2Cr in a / o ) and Inconel 625 (Ni-19Cr-9Mo-4Nb in w / o ) fabricated by electron beam melting (EBM) were compared with a 10:1 blend of TiAl: alloy 625 pre-alloyed powders producing a complex alloy having the composition 48Ti-24Al-9Ni-8Nb-4.5Cr-4Ni (in w / o ). The blended alloy hardness (HV) reached 7.5 GPa in contrast to 1.4 GPa for the Alloy 625 and 4.0 for the 2-phase TiAl alloy. Reticulated mesh samples and stochastic foam samples prepared from the blended alloy by EBM exhibited a Relative Stiffness versus Relative density plotted on a log-log basis consistent with other reference alloys fitted to a straight line with a slope n = 2 for ideal open cellular materials.
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Effect of Melt Scan Rate on Microstructure and Macrostructure for Electron Beam Melting of Ti-6Al-4V
2012Co-Authors: Karina Puebla, Edwin Martinez, Francisco Medina, Lawrence E Murr, Sara M. Gaytan, Ryan WickerAbstract:Microstructure and variations in porosity in Ti-6Al-4V samples built with electron beam melting (EBM) over a range of melt scan speeds, ranging from 100 mm·s-1 to 1000 mm·s-1 were examined. Microstructure was characterized by refinement of α-phase and transformation to α′-martensite. Light optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to observe these phenomena, while corresponding tensile testing and associated macro and microindentation hardness measurements were used to define the microstructural variations. Relative Stiffness was observed to be linearly log-log related to Relative density, corresponding to ideal porosity associated with open-cellular structures.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: Lawrence E Murr, Patrick W. Shindo, Y X Tian, Krista Amato, Edwin Martinez, Shujun Li, X.y. Cheng, Francisco Medina, Sara M. Gaytan, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily alpha-phase acicular platelets while the mesh and foam structures were characterized by alpha'-martensite with some residual alpha. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced similar to 2 mu m in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness. (C) 2011 Elsevier Ltd. All rights reserved.
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characterization of ti 6al 4v open cellular foams fabricated by additive manufacturing using electron beam melting
2010Co-Authors: Lawrence E Murr, Edwin Martinez, Francisco Medina, Sara M. Gaytan, Jose L Martinez, D H Hernandez, B I Machado, D A Ramirez, Ryan B WickerAbstract:Abstract Ti–6Al–4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable Stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of Relative Stiffness versus Relative density were in good agreement with the Gibson–Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.
Francisco Medina - One of the best experts on this subject based on the ideXlab platform.
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Effect of Melt Scan Rate on Microstructure and Macrostructure for Electron Beam Melting of Ti-6Al-4V
2012Co-Authors: Karina Puebla, Edwin Martinez, Francisco Medina, Lawrence E Murr, Sara M. Gaytan, Ryan WickerAbstract:Microstructure and variations in porosity in Ti-6Al-4V samples built with electron beam melting (EBM) over a range of melt scan speeds, ranging from 100 mm·s-1 to 1000 mm·s-1 were examined. Microstructure was characterized by refinement of α-phase and transformation to α′-martensite. Light optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to observe these phenomena, while corresponding tensile testing and associated macro and microindentation hardness measurements were used to define the microstructural variations. Relative Stiffness was observed to be linearly log-log related to Relative density, corresponding to ideal porosity associated with open-cellular structures.
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microstructure and mechanical properties of open cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting
2011Co-Authors: Lawrence E Murr, Patrick W. Shindo, Y X Tian, Krista Amato, Edwin Martinez, Shujun Li, X.y. Cheng, Francisco Medina, Sara M. Gaytan, Ryan B WickerAbstract:Total knee replacement implants consisting of a Co-29Cr-6Mo alloy femoral component and a Ti-6Al-4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti-6Al-4V solid prototype microstructures were primarily alpha-phase acicular platelets while the mesh and foam structures were characterized by alpha'-martensite with some residual alpha. The Co-29Cr-6Mo containing 0.22% C formed columnar (directional) Cr(23)C(6) carbides spaced similar to 2 mu m in the build direction, while HIP-annealed Co-Cr alloy exhibited an intrinsic stacking fault microstructure. A log-log plot of Relative Stiffness versus Relative density for Ti-6Al-4V and Co-29Cr-6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n = 2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone Stiffness. (C) 2011 Elsevier Ltd. All rights reserved.
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characterization of ti 6al 4v open cellular foams fabricated by additive manufacturing using electron beam melting
2010Co-Authors: Lawrence E Murr, Edwin Martinez, Francisco Medina, Sara M. Gaytan, Jose L Martinez, D H Hernandez, B I Machado, D A Ramirez, Ryan B WickerAbstract:Abstract Ti–6Al–4V open cellular foams were fabricated by additive manufacturing using electron beam melting (EBM). Foam models were developed from CT-scans of aluminum open cellular foams and embedded in CAD for EBM. These foams were fabricated with solid cell structures as well as hollow cell structures and exhibit tailorable Stiffness and strength. The strength in proportion to the measured microindentation hardness is as much as 40% higher for hollow cell (wall) structures in contrast to solid, fully dense EBM fabricated components. Plots of Relative Stiffness versus Relative density were in good agreement with the Gibson–Ashby model for open cellular foam materials. Stiffness or Young's modulus values measured using a resonant frequency-damping analysis technique were found to vary inversely with porosity especially for solid cell wall, open cellular structure foams. These foams exhibit the potential for novel biomedical, aeronautics, and automotive applications.