Microstructure, mechanical properties and dry wear resistance of β-type Ti-15Mo-xNb alloys for biomedical applications
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology, Harbin 150001, China)
2. National Key Laboratory for Precision Hot Processing of Metals,Harbin Institute of Technology, Harbin 150001, China)
Abstract: In order to study the effect of element Nb on the microstructure and properties of the biomedical β-type Ti-Mo based alloys, Ti-15Mo-xNb (x=5, 10, 15 and 20 in %) alloys were investigated. The dry wear resistance of β-type Ti-15Mo-xNb alloys against Gr15 ball was investigated on CJS111A ball-disk wear instrument. Experimental results indicate that crystal structure and morphology of the Ti-15Mo-xNb alloys are sensitive to their Nb contents. Ti-15Mo-xNb alloys match those for β phase peaks and no any phases are found. The Vickers hardness values of all the Ti-15Mo-xNb alloys are higher than HV200. The compression yield strength of the Ti-15Mo-5Nb alloy is the lowest and that of the Ti-15Mo-10Nb alloy is the highest. For all the Ti-15Mo-xNb alloys, the friction coefficient is not constant but takes a higher value. In dry condition, SEM study reveals deep parallel scars on the wear surfaces of all the Ti-15Mo-xNb alloys under different loads. The friction coefficient of the Ti-15Mo-5Nb alloy under 1 N is the lowest. The wear principal mechanism for Ti-15Mo-xNb alloys is adhesive wear.
Key words: β-type Ti-Mo-Nb alloys; wear resistance; adhesive wear; microstructure; mechanical properties