The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Chan Hee Park - One of the best experts on this subject based on the ideXlab platform.
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Breaking the limit of Young’s modulus in low-cost Ti–Nb–Zr alloy for biomedical implant applications
Journal of Alloys and Compounds, 2020Co-Authors: Taekyung Lee, Sang Won Lee, In-su Kim, Young Hoon Moon, Hyoung Seop Kim, Chan Hee ParkAbstract:Abstract Biomedical implant material simultaneously requires high yield strength and low Young’s modulus. The lower boundary for the YM of Ti–13Nb–13Zr alloys is regarded to be approximately 65 GPa, which limits further improvement in their Mechanical Compatibility. This study proposes a novel process of cold caliber rolling to break this limit and decrease YM to 47 GPa, which is the bare minimum value since the development of this alloying system. As a result, the developed alloy exhibits a Mechanical Compatibility similar to those of most advanced β-Ti alloys but with a significantly lower amount of high-cost alloying elements. This study attributed the Mechanical improvement to three mechanisms based on microstructural characterizations. Manufacturing advantages of the suggested method were discussed as well.
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improved pre osteoblast response and Mechanical Compatibility of ultrafine grained ti 13nb 13zr alloy
Clinical Oral Implants Research, 2011Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P<0.05). The UFG and CG Ti–13Nb–13Zr alloys displayed significantly increased cellular attachment compared with CG Ti–6Al–4V alloy (P<0.05). The UFG Ti–13Nb–13Zr supported better cell spreading and more numerous focal adhesions. ALP activity (P<0.05) and mRNA expressions of the osteoblast transcription factor genes (osterix, Runx2) and marker gene for osteoblast differentiation (osteocalcin) were markedly increased in cells grown on the UFG substrate compared with CG substrates at early incubation timepoints. Conclusion: Enhanced pre-osteoblast response to UFG Ti–13Nb–13Zr substrate is attributable to the non-cytotoxic alloying elements and the submicron scale grain size contributes to the superior surface hydrophilicity and abundant grain boundaries favorable for cell behavior. These findings indicate that dynamic globularized UFG Ti–13Nb–13Zr alloy is promising for load-bearing endosseous implant material because of excellent Mechanical and biological compatibilites. To cite this article: Park CH, Lee CS, Kim Y-J, Jang J-H, Suh J-Y, Park J-W. Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy. Clin. Oral Impl. Res. 22, 2011; 735–742 doi: 10.1111/j.1600-0501.2010.02053.x
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Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy
Clinical oral implants research, 2010Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P
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enhanced Mechanical Compatibility of submicrocrystalline ti 13nb 13zr alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Chan Hee Park, Jinwoo Park, Jongtaek Yeom, Young Soo Chun, Chong Soo LeeAbstract:Abstract This study aimed to achieve enhanced Mechanical Compatibility of Ti–13Nb–13Zr alloy by producing submicrocrystalline microstructure without imposing severe strains. In order to find the optimum processing conditions, a series of compression tests was performed for initial martensite microstructure in strain ranges up to 0.8 and 1.4, the strain rate range of 10 −3 to 1 s −1 and the temperature range of 500–700 °C. Based on the microstructural analysis, the submicrocrystalline (∼0.4 μm) alloy consisting of high-angle grain boundaries was produced via dynamic globularization at temperature of 600 °C, equivalent strain rate of 10 −1 s −1 and strain of 1.4, which showed about 25% enhanced Mechanical Compatibility as compared to the conventionally produced ones. The formation of submicrocrystalline microstructure at relatively low strain was investigated by examining the microstructure before and after dynamic globularization.
Jinwoo Park - One of the best experts on this subject based on the ideXlab platform.
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improved pre osteoblast response and Mechanical Compatibility of ultrafine grained ti 13nb 13zr alloy
Clinical Oral Implants Research, 2011Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P<0.05). The UFG and CG Ti–13Nb–13Zr alloys displayed significantly increased cellular attachment compared with CG Ti–6Al–4V alloy (P<0.05). The UFG Ti–13Nb–13Zr supported better cell spreading and more numerous focal adhesions. ALP activity (P<0.05) and mRNA expressions of the osteoblast transcription factor genes (osterix, Runx2) and marker gene for osteoblast differentiation (osteocalcin) were markedly increased in cells grown on the UFG substrate compared with CG substrates at early incubation timepoints. Conclusion: Enhanced pre-osteoblast response to UFG Ti–13Nb–13Zr substrate is attributable to the non-cytotoxic alloying elements and the submicron scale grain size contributes to the superior surface hydrophilicity and abundant grain boundaries favorable for cell behavior. These findings indicate that dynamic globularized UFG Ti–13Nb–13Zr alloy is promising for load-bearing endosseous implant material because of excellent Mechanical and biological compatibilites. To cite this article: Park CH, Lee CS, Kim Y-J, Jang J-H, Suh J-Y, Park J-W. Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy. Clin. Oral Impl. Res. 22, 2011; 735–742 doi: 10.1111/j.1600-0501.2010.02053.x
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Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy
Clinical oral implants research, 2010Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P
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enhanced Mechanical Compatibility of submicrocrystalline ti 13nb 13zr alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Chan Hee Park, Jinwoo Park, Jongtaek Yeom, Young Soo Chun, Chong Soo LeeAbstract:Abstract This study aimed to achieve enhanced Mechanical Compatibility of Ti–13Nb–13Zr alloy by producing submicrocrystalline microstructure without imposing severe strains. In order to find the optimum processing conditions, a series of compression tests was performed for initial martensite microstructure in strain ranges up to 0.8 and 1.4, the strain rate range of 10 −3 to 1 s −1 and the temperature range of 500–700 °C. Based on the microstructural analysis, the submicrocrystalline (∼0.4 μm) alloy consisting of high-angle grain boundaries was produced via dynamic globularization at temperature of 600 °C, equivalent strain rate of 10 −1 s −1 and strain of 1.4, which showed about 25% enhanced Mechanical Compatibility as compared to the conventionally produced ones. The formation of submicrocrystalline microstructure at relatively low strain was investigated by examining the microstructure before and after dynamic globularization.
Chong Soo Lee - One of the best experts on this subject based on the ideXlab platform.
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improved pre osteoblast response and Mechanical Compatibility of ultrafine grained ti 13nb 13zr alloy
Clinical Oral Implants Research, 2011Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P<0.05). The UFG and CG Ti–13Nb–13Zr alloys displayed significantly increased cellular attachment compared with CG Ti–6Al–4V alloy (P<0.05). The UFG Ti–13Nb–13Zr supported better cell spreading and more numerous focal adhesions. ALP activity (P<0.05) and mRNA expressions of the osteoblast transcription factor genes (osterix, Runx2) and marker gene for osteoblast differentiation (osteocalcin) were markedly increased in cells grown on the UFG substrate compared with CG substrates at early incubation timepoints. Conclusion: Enhanced pre-osteoblast response to UFG Ti–13Nb–13Zr substrate is attributable to the non-cytotoxic alloying elements and the submicron scale grain size contributes to the superior surface hydrophilicity and abundant grain boundaries favorable for cell behavior. These findings indicate that dynamic globularized UFG Ti–13Nb–13Zr alloy is promising for load-bearing endosseous implant material because of excellent Mechanical and biological compatibilites. To cite this article: Park CH, Lee CS, Kim Y-J, Jang J-H, Suh J-Y, Park J-W. Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy. Clin. Oral Impl. Res. 22, 2011; 735–742 doi: 10.1111/j.1600-0501.2010.02053.x
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Improved pre-osteoblast response and Mechanical Compatibility of ultrafine-grained Ti–13Nb–13Zr alloy
Clinical oral implants research, 2010Co-Authors: Chan Hee Park, Chong Soo Lee, Younjeong Kim, Jehee Jang, Joyoung Suh, Jinwoo ParkAbstract:Objective: Metallic implantation materials having high yield strength, low elastic modulus, and non-cytotoxic alloying elements would be advantageous for the long-term stability of implants. This study assessed the surface and Mechanical properties, and also in vitro osteoconductivity of ultrafine-grained (UFG) Ti–13Nb–13Zr alloy produced by dynamic globularization without any severe deformation for future biomedical applications as an endosseous implant material. Material and methods: The surface characteristics and Mechanical properties were investigated by orientation image microscopy, contact angle measurements, optical profilometry, and uniaxial tension tests. Mouse calvaria-derived pre-osteoblastic cell (MC3T3-E1) attachment, spreading, viability, alkaline phosphatase (ALP) activity, and quantitative analysis of osteoblastic gene expression on UFG Ti–13Nb–13Zr alloy were compared with coarse-grained (CG) Ti–13Nb–13Zr and CG Ti–6Al–4V alloys. Results: Dynamic globularized Ti–13Nb–13Zr alloy has an ultrafine grain size (0.3 μm) and an excellent combination of yield strength and elastic modulus compared with CG alloys, which displayed significantly lower water contact angles compared with CG alloys (P
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enhanced Mechanical Compatibility of submicrocrystalline ti 13nb 13zr alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Chan Hee Park, Jinwoo Park, Jongtaek Yeom, Young Soo Chun, Chong Soo LeeAbstract:Abstract This study aimed to achieve enhanced Mechanical Compatibility of Ti–13Nb–13Zr alloy by producing submicrocrystalline microstructure without imposing severe strains. In order to find the optimum processing conditions, a series of compression tests was performed for initial martensite microstructure in strain ranges up to 0.8 and 1.4, the strain rate range of 10 −3 to 1 s −1 and the temperature range of 500–700 °C. Based on the microstructural analysis, the submicrocrystalline (∼0.4 μm) alloy consisting of high-angle grain boundaries was produced via dynamic globularization at temperature of 600 °C, equivalent strain rate of 10 −1 s −1 and strain of 1.4, which showed about 25% enhanced Mechanical Compatibility as compared to the conventionally produced ones. The formation of submicrocrystalline microstructure at relatively low strain was investigated by examining the microstructure before and after dynamic globularization.
Nikolaj Gadegaard - One of the best experts on this subject based on the ideXlab platform.
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Mechanical Compatibility of sol–gel annealing with titanium for orthopaedic prostheses
Journal of Materials Science: Materials in Medicine, 2015Co-Authors: Andrew I. M. Greer, Teoh S. Lim, Alistair S. Brydone, Nikolaj GadegaardAbstract:Sol–gel processing is an attractive method for large-scale surface coating due to its facile and inexpensive preparation, even with the inclusion of precision nanotopographies. These are desirable traits for metal orthopaedic prostheses where ceramic coatings are known to be osteoinductive and the effects may be amplified through nanotexturing. However there are a few concerns associated with the application of sol–gel technology to orthopaedics. Primarily, the annealing stage required to transform the sol–gel into a ceramic may compromise the physical integrity of the underlying metal. Secondly, loose particles on medical implants can be carcinogenic and cause inflammation so the coating needs to be strongly bonded to the implant. These concerns are addressed in this paper. Titanium, the dominant material for orthopaedics at present, is examined before and after sol–gel processing for changes in hardness and flexural modulus. Wear resistance, bending and pull tests are also performed to evaluate the ceramic coating. The findings suggest that sol–gel coatings will be compatible with titanium implants for an optimum temperature of 500 °C.
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Mechanical Compatibility of sol-gel annealing with titanium for orthopaedic prostheses.
Journal of materials science. Materials in medicine, 2015Co-Authors: Andrew I. M. Greer, Teoh S. Lim, Alistair S. Brydone, Nikolaj GadegaardAbstract:Sol–gel processing is an attractive method for large-scale surface coating due to its facile and inexpensive preparation, even with the inclusion of precision nanotopographies. These are desirable traits for metal orthopaedic prostheses where ceramic coatings are known to be osteoinductive and the effects may be amplified through nanotexturing. However there are a few concerns associated with the application of sol–gel technology to orthopaedics. Primarily, the annealing stage required to transform the sol–gel into a ceramic may compromise the physical integrity of the underlying metal. Secondly, loose particles on medical implants can be carcinogenic and cause inflammation so the coating needs to be strongly bonded to the implant. These concerns are addressed in this paper. Titanium, the dominant material for orthopaedics at present, is examined before and after sol–gel processing for changes in hardness and flexural modulus. Wear resistance, bending and pull tests are also performed to evaluate the ceramic coating. The findings suggest that sol–gel coatings will be compatible with titanium implants for an optimum temperature of 500 °C.
Lian Zhou - One of the best experts on this subject based on the ideXlab platform.
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Compressive Mechanical Compatibility of anisotropic porous Ti6Al4V alloys in the range of physiological strain rate for cortical bone implant applications.
Journal of materials science. Materials in medicine, 2015Co-Authors: Hongchao Kou, Huang Tingting, Lian ZhouAbstract:Porous titanium and its alloys are believed to be promising materials for bone implant applications, since they can reduce the "stress shielding" effect by tailoring porosity and improve fixation of implant through bone ingrowth. In the present work, porous Ti6Al4V alloys for biomedical application were fabricated by diffusion bonding of alloy meshes. Compressive Mechanical behavior and Compatibility in the range of physiological strain rate were studied under quasi-static and dynamic conditions. The results show that porous Ti6Al4V alloys possess anisotropic structure with elongated pores in the out-of-plane direction. For porous Ti6Al4V alloys with 60-70 % porosity, more than 40 % pores are in the range of 200-500 μm which is the optimum pore size suited for bone ingrowth. Quasi-static Young's modulus and yield stress of porous Ti6Al4V alloys with 30-70 % relative density are in the range of 6-40 GPa and 100-500 MPa, respectively. Quasi-static compressive properties can be quantitatively tailored by porosity to match those of cortical bone. Strain rate sensitivity of porous Ti6Al4V alloys is related to porosity. Porous Ti6Al4V alloys with porosity higher than 50 % show enhanced strain rate sensitivity, which is originated from that of base materials and micro-inertia effect. Porous Ti6Al4V alloys with 60-70 % porosity show superior compressive Mechanical Compatibility in the range of physiological strain rate for cortical bone implant applications.
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Fabrication and Compressive Properties of Porous Ti6Al4V Alloy with Elongated Pores for Biomedical Application
Materials Science Forum, 2015Co-Authors: Ge Jun Liu, Hongchao Kou, Lian ZhouAbstract:Porous Ti6Al4V alloys with anisotropic structure for biomedical application was fabricated by diffusion bonding of titanium alloy meshes. Compressive Mechanical Compatibility of the alloys is investigated as human bone implants. It is concluded that the fabrication processing for porous Ti6Al4V alloys has better control of the porosity. The pore structure of porous titanium is anisotropic, with elongated and square pores in the out-of-plane and in-plane direction, respectively, which is suited for bone ingrowth. The compressive Young’s modulus and yield stress of porous Ti6Al4V alloy compressed in the out-of-plane direction are 12.2 GPa and 171.4 MPa, respectively, which is compatible with those for the cortical bones.
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anisotropic porous titanium with superior Mechanical Compatibility in the range of physiological strain rate for trabecular bone implant applications
Materials Letters, 2014Co-Authors: Hongchao Kou, Lian ZhouAbstract:Abstract Porous titanium for biomedical application was fabricated by diffusion bonding of titanium meshes. Compressive Mechanical Compatibility and strain rate sensitivity were studied in the range of physiological strain rate under quasi-static and dynamic conditions. The results show that porous titanium presents anisotropic pore structure suited for bone ingrowth. Quasi-static compressive Young׳s modulus and yield stress are in the range of 0.4–6.5 GPa and 5–105 MPa, respectively, for porous titanium with 30–70% relative density. Based on the Gibson–Ashby model, quasi-static compressive properties can be quantitatively designed and tailored with respect to relative density to match those of human trabecular bone. Porous titanium with 30–40% relative density compressed in the out-of-plane direction shows excellent Mechanical Compatibility in strain rate sensitivity, and has huge potential for application in human trabecular bone implants.
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Investigation on Mechanical Compatibility Matching for Biomedical Titanium Alloys
Key Engineering Materials, 2005Co-Authors: Lian Zhou, Lijuan Luo, Maohong FanAbstract:The effects of alloying elements such as Mo, Sn, Zr, Nb, deforming-rate, solid solution and aging treatment on Mechanical property and microstructure of near βtype biomedical Ti alloys based on Ti-Nb-Zr system were studied. The Influential factors and their solution were discussed to keep matching of strength, elastic modulus, plasticity and toughness. Ti-Zr-Mo-Nb and Ti-Zr-Sn-Mo-Nb alloy systems possess excellent bioCompatibility, lower elastic modulus, higher strength, finer plasticity and fracture toughness matching by means of solid solution and ageing treatment which are much more suitable for surgical implant and orthopedic materials.