The biocompatible metallic implants with strong osteointegration often lack the ability of anti-infection.The biocompatible niobium(Nb)containing the antibacterial copper(Cu),the obtained Nb-Cu alloy,could be a potent...The biocompatible metallic implants with strong osteointegration often lack the ability of anti-infection.The biocompatible niobium(Nb)containing the antibacterial copper(Cu),the obtained Nb-Cu alloy,could be a potential candidate to solve this issue.To test this hypothesis,ultrafine-grained Nb-Cu immiscible alloys were fabricated via mechanical alloying and spark plasma sintering.The aim of this study was to investigate the microstructure,mechanical properties,magnetic susceptibility,corrosion behavior,ion release,and the bactericidal activity,biocompatibility and osteogenic potential of the Nb-Cu alloys in vitro and their osteogenesis and osteointegration ability in vivo with a comparison with pure Nb.The rat cranial defect model and the bone screws insertion in rabbit femoral bone were used to evaluate the osteogenesis and osteointegration ability,respectively.The results showed that after the addition of 3 wt.%of Cu,the compressive strength was significantly improved from 1.57 GPa to 2.21 GPa and the magnetic susceptibility slightly decreased.The Nb-3 wt.%Cu(Nb-3Cu)alloy exhibited higher corrosion resistance than pure Nb in Hank’s solution and strong bactericidal activity against both E.coli and S.aureus.In vitro,the Nb-3Cu alloy showed comparable biocompatibility with pure Nb.The addition of 3 wt.%Cu also significantly enhanced the expression of osteogenesis-related genes(RUNX2,ALP,COLA1 and OCN)of pre-osteoblasts.In vivo,the Nb-3Cu alloy promoted bone regeneration at the defect sites and showed enhanced osteointegration after 12 weeks of implantation.Such a good combination of high mechanical strength and corrosion resistance,strong antibacterial activity and improved osteogenesis and osseointegration ability enables the present Nb-3Cu alloy a promising candidate for heavy load-bearing hard tissue repair.展开更多
A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El...A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El)on the defects,melt pool morphology,microstructure,and properties of the alloy was systematically investigated.The results show that the optimized process parameters for preparing Cu−Cr−Nb−Y alloy with relative density over 99.5%are P=300−350 W and v=650−800 mm/s,corresponding to El=0.375−0.538 J/mm.When E_(l)<0.3 J/mm,increasing P or decreasing v can enhance the continuity and size of the melt pool,reduce the lack-of-fusion defects,and increase the relative density.However,excessively high E_(l)leads to a deeper melt pool,more keyholes,and reduced relative density.The grain size of the as-built Cu−Cr−Nb−Y alloy shows a bimodal distribution,with fine grains at the center and coarse grains at the edge of the melt pool.Increasing P or decreasing v increases the average grain size and(110)texture intensity.The alloy fabricated with P=350 W and v=800 mm/s displays the highest relative density of 99.82%.The yield strength,tensile strength,and elongation are(443±5)MPa,(699±4)MPa,and(17.1±0.7)%,respectively.展开更多
The mechanical properties and fracture morphologies of Cu/Nb multilayer composites under electric-assisted tension(EAT)were investigated.Results show that the generated Joule-heat leads to obvious stress softening wit...The mechanical properties and fracture morphologies of Cu/Nb multilayer composites under electric-assisted tension(EAT)were investigated.Results show that the generated Joule-heat leads to obvious stress softening with the increase in current density.However,the elongation decreases,which is closely related to the characteristic fracture behavior of Cu/Nb multilayer composites during EAT.The fracture pattern is gradually transformed from ductile fracture to melt fracture with the increase in current density.展开更多
基金partial financial support from the National Natural Science Foundation of China (No. 52101231)the Science Fund of Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing,China (No. AMGM2021F09)the Natural Science Foundation of Shandong Province,China (No. ZR2021QE044)。
基金the National Natural Science Foundation of China(No.52122102)the Natural Science Foundation of Guangdong(No.2019A1515011755)the Shenzhen Fundamental Research Project(No.JCYJ20190809153205492)。
文摘The biocompatible metallic implants with strong osteointegration often lack the ability of anti-infection.The biocompatible niobium(Nb)containing the antibacterial copper(Cu),the obtained Nb-Cu alloy,could be a potential candidate to solve this issue.To test this hypothesis,ultrafine-grained Nb-Cu immiscible alloys were fabricated via mechanical alloying and spark plasma sintering.The aim of this study was to investigate the microstructure,mechanical properties,magnetic susceptibility,corrosion behavior,ion release,and the bactericidal activity,biocompatibility and osteogenic potential of the Nb-Cu alloys in vitro and their osteogenesis and osteointegration ability in vivo with a comparison with pure Nb.The rat cranial defect model and the bone screws insertion in rabbit femoral bone were used to evaluate the osteogenesis and osteointegration ability,respectively.The results showed that after the addition of 3 wt.%of Cu,the compressive strength was significantly improved from 1.57 GPa to 2.21 GPa and the magnetic susceptibility slightly decreased.The Nb-3 wt.%Cu(Nb-3Cu)alloy exhibited higher corrosion resistance than pure Nb in Hank’s solution and strong bactericidal activity against both E.coli and S.aureus.In vitro,the Nb-3Cu alloy showed comparable biocompatibility with pure Nb.The addition of 3 wt.%Cu also significantly enhanced the expression of osteogenesis-related genes(RUNX2,ALP,COLA1 and OCN)of pre-osteoblasts.In vivo,the Nb-3Cu alloy promoted bone regeneration at the defect sites and showed enhanced osteointegration after 12 weeks of implantation.Such a good combination of high mechanical strength and corrosion resistance,strong antibacterial activity and improved osteogenesis and osseointegration ability enables the present Nb-3Cu alloy a promising candidate for heavy load-bearing hard tissue repair.
基金financially supported by the Project of Chinese Academy of Engineering(Nos.2019-XZ-11 and 2023-XY-18)the Open Fund of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials of China(No.HKDNM201907)。
文摘A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El)on the defects,melt pool morphology,microstructure,and properties of the alloy was systematically investigated.The results show that the optimized process parameters for preparing Cu−Cr−Nb−Y alloy with relative density over 99.5%are P=300−350 W and v=650−800 mm/s,corresponding to El=0.375−0.538 J/mm.When E_(l)<0.3 J/mm,increasing P or decreasing v can enhance the continuity and size of the melt pool,reduce the lack-of-fusion defects,and increase the relative density.However,excessively high E_(l)leads to a deeper melt pool,more keyholes,and reduced relative density.The grain size of the as-built Cu−Cr−Nb−Y alloy shows a bimodal distribution,with fine grains at the center and coarse grains at the edge of the melt pool.Increasing P or decreasing v increases the average grain size and(110)texture intensity.The alloy fabricated with P=350 W and v=800 mm/s displays the highest relative density of 99.82%.The yield strength,tensile strength,and elongation are(443±5)MPa,(699±4)MPa,and(17.1±0.7)%,respectively.
基金National Natural Science Foundation of China(52305349)China Postdoctoral Science Foundation(2023M730837)+2 种基金Natural Science Basic Research Program of Shaanxi Province(2023-JC-QN-0518)Heilongjiang Provincial Natural Science Foundation of China(LH2023E033)Supported by CGN-HIT Advanced Nuclear and New Energy Research Institute(CGN-HIT202305)。
文摘The mechanical properties and fracture morphologies of Cu/Nb multilayer composites under electric-assisted tension(EAT)were investigated.Results show that the generated Joule-heat leads to obvious stress softening with the increase in current density.However,the elongation decreases,which is closely related to the characteristic fracture behavior of Cu/Nb multilayer composites during EAT.The fracture pattern is gradually transformed from ductile fracture to melt fracture with the increase in current density.
