A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection performance.To meet these requirements,the low-elastic-modulus alloy—Ti–35Nb–2Ta–3Zr—was used as the s...A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection performance.To meet these requirements,the low-elastic-modulus alloy—Ti–35Nb–2Ta–3Zr—was used as the substrate,and functional coatings that contained bioceramics and Ag ions were prepared for coating on TiO_(2)nanotubes(diameter:(80±20)nm and(150±40)nm)using anodization,deposition,and spin-coating methods.The effects of the bioceramics(nano-β-tricalcium phosphate,microhydroxyapatite(micro-HA),and meso-CaSiO_(3))and Ag nanoparticles(size:(50±20)nm)on the antibacterial activity and the tribocorrosion,corrosion,and early in vitro osteogenic behaviors of the nanotubes were investigated.The tribocorrosion and corrosion results showed that the wear rate and corrosive rate were highly dependent on the features of the nanotube surface.Micro-HA showed great wear resistance with a wear rate of(1.26±0.06)×10^(−3)mm^(3)/(N·m)due to adhesive and abrasivewear.Meso-CaSiO_(3)showed enhanced cell adhesion,proliferation,and alkaline phosphatase activity.The coatings that contained nano-Ag exhibited good antibacterial activity with an antibacterial rate of≥89.5%against Escherichia coli.These findings indicate that hybrid coatings may have the potential to accelerate osteogenesis.展开更多
The present study investigated the microstructure,nanomechanics,and corrosion behavior of AlCoCuFeNi high entropy alloys fabricated by selective laser melting(SLM)and laser metal deposition(LMD).The microstructure of ...The present study investigated the microstructure,nanomechanics,and corrosion behavior of AlCoCuFeNi high entropy alloys fabricated by selective laser melting(SLM)and laser metal deposition(LMD).The microstructure of SLM-processed specimens was mainly composed of columnar-grained BCC matrix(^90μm in width)and Cu-rich twinned FCC phase.The columnar grains grew epitaxially along the building direction and exhibited a strong{001}texture.In comparison,a coarse columnar-grained BCC matrix(^150μm in width)with a stronger<001>texture,rod-like B2 precipitates,and large core-shell structured FCC phases were formed in the LMD-processed specimens due to the higher heat accumulation effect.Consequently,the LMD-processed specimens showed a lower hardness,wear resistance,and corrosion resistance,but higher creep resistance and reduced Young's modulus than the SLM-processed specimens.Hot cracks occurred in both types of specimens,which could not be completely suppressed due to Cu segregation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52071346,52111530193,and 52274387)the Natural Science Foundation of Hunan Province for Distinguished Young Scholars(No.2023JJ10075)+3 种基金the Hunan Provincial Natural Science Foundation of China(No.2021JJ30846)the Central South University Research Program of Advanced Interdisciplinary Studies(No.2023QYJC038)the Funding for the Medical Engineering Cross Disciplinary Project at Shanghai Jiao Tong University,and the Fundamental Research Funds for the Central Universities of Central South University(No.2022ZZTS0402)The authors would also thank Sinoma Institute of Materials Research(Guangzhou)Co.,Ltd.for the assistance with the TEM characterization.
文摘A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection performance.To meet these requirements,the low-elastic-modulus alloy—Ti–35Nb–2Ta–3Zr—was used as the substrate,and functional coatings that contained bioceramics and Ag ions were prepared for coating on TiO_(2)nanotubes(diameter:(80±20)nm and(150±40)nm)using anodization,deposition,and spin-coating methods.The effects of the bioceramics(nano-β-tricalcium phosphate,microhydroxyapatite(micro-HA),and meso-CaSiO_(3))and Ag nanoparticles(size:(50±20)nm)on the antibacterial activity and the tribocorrosion,corrosion,and early in vitro osteogenic behaviors of the nanotubes were investigated.The tribocorrosion and corrosion results showed that the wear rate and corrosive rate were highly dependent on the features of the nanotube surface.Micro-HA showed great wear resistance with a wear rate of(1.26±0.06)×10^(−3)mm^(3)/(N·m)due to adhesive and abrasivewear.Meso-CaSiO_(3)showed enhanced cell adhesion,proliferation,and alkaline phosphatase activity.The coatings that contained nano-Ag exhibited good antibacterial activity with an antibacterial rate of≥89.5%against Escherichia coli.These findings indicate that hybrid coatings may have the potential to accelerate osteogenesis.
基金financially supported by the National Natural Science Foundation of China(Nos.52111530193 and 52020105013)the Key Research and Development Program of Hunan Province(No.2022SK2006)+1 种基金the Fundamental Research Funds for the Central University of Central South University(No.2021ZZTS0098)the HK Research Grants Council(ECS 25202719 and GRF 15227121)。
文摘The present study investigated the microstructure,nanomechanics,and corrosion behavior of AlCoCuFeNi high entropy alloys fabricated by selective laser melting(SLM)and laser metal deposition(LMD).The microstructure of SLM-processed specimens was mainly composed of columnar-grained BCC matrix(^90μm in width)and Cu-rich twinned FCC phase.The columnar grains grew epitaxially along the building direction and exhibited a strong{001}texture.In comparison,a coarse columnar-grained BCC matrix(^150μm in width)with a stronger<001>texture,rod-like B2 precipitates,and large core-shell structured FCC phases were formed in the LMD-processed specimens due to the higher heat accumulation effect.Consequently,the LMD-processed specimens showed a lower hardness,wear resistance,and corrosion resistance,but higher creep resistance and reduced Young's modulus than the SLM-processed specimens.Hot cracks occurred in both types of specimens,which could not be completely suppressed due to Cu segregation.
