Microstructure, wear resistance, and corrosion performance of Ti35Zr28Nb alloy fabricated by powder metallurgy for orthopedic applications

Wei Xu¹，Xin Lu¹，Jingjing Tian²，Chao Huang¹，Miao Chen¹，Yu Yan¹，Luning Wang¹，Xuanhui Qu¹，Cuie Wen³

1. Beijing Advanced Innovation Center for Materials Genome Engineering, Institute for Advanced Materials and Technology, University of Science and Technology Beijing2. Central Laboratory, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences3. School of Engineering, RMIT University

摘 要：A ternary Ti35Zr28Nb alloy was fabricated by powder metallurgy（PM） from pre-alloyed powder. The microstructure, hardness, corrosion behavior, and wear response of the produced alloy were investigated systematically. The results show that nearly full dense Ti35Zr28Nb alloy（relative density is 98.1 ± 1.2 %）can be fabricated by PM. The microstructure was dominated with uniform phase. The Ti35Zr28Nb alloy displayed spontaneous passivity in a naturally aerated simulated body fluid（SBF） solution at 37 ± 0.5°C.The Ti35Zr28Nb alloy exhibited the highest corrosion resistance as compared to as-cast Ti6Al4V and pure Ti because of the formation of a protective passive film containing TiO₂, Nb₂O₅, and ZrO₂, including the highest corrosion potential（-0.22 ± 0.01 V）, the lowest corrosion current density（57.45 ± 1.88 nA）, the lowest passive potential（0.05 ± 0.01 V） and the widest passivation range（1.29 ± 0.09 V）. Under the same wear condition, the wear rate of the Ti35Zr28Nb alloy（0.0021 ± 0.0002 mm³/m·N） was lower than that of the CP Ti（0.0029 ± 0.0004 mm³/m·N） and close to that of the Ti6Al4V（0.0020 ± 0.0003 mm³/m·N）.The wear mechanism of the Ti35Zr28Nb alloy was mainly dominated by abrasive wear, accompanied by adhesive wear. The highest corrosion resistance together with the adequate wear resistance makes the PM-fabricated Ti35Zr28Nb alloy an attractive candidate for orthopedic implant materials.

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