Papers by Author: X.N. Zhang

Abstract: Recently there is increasing demand for the development of new -type titanium with a low elastic modulus for surgical orthopaedic implant applications. In this paper, we developed a new Ti-Mo-Zr alloy based on the d-electron alloy design theory. The designed Ti-12Mo-5Zr (at%) alloy was then produced using ingot metallurgy and evaluated pertaining to the effect of heat treatment on the microstructure and mechanical properties. The alloy exhibited a relatively low Young’s modulus similar to some typical  orthopaedic titanium alloys. Yield strength, tensile strength and Young’s modulus of the alloy decreased after solid solution treatment. The mechanism by which heat treatment affects the mechanical properties is discussed.

Abstract: With their very low density, excellent biocompatibility, and good mechanochemical properties, titanium alloys have been considered a high-end material for making biomedical devices and instruments. However, they still have some substantial challenges to be overcome. One major problem, which eventually leads to revision surgery, is the implant loosening- a result of tissue migration, formation of wear debris, insufficient interface bonding between bone and implant, and stress shielding. Nanosized features in the material have the potential to provide a solution to these problems. A nanostructured surface is able to not only promote tissue ingrowth, but also increase the surface hardness and therefore improving the wear resistance and enhancing fatigue strength. This paper reports our recent work on how surface treatment on titanium alloys changes their mechanical properties. The mechanism by which the surface nanostructuring alters mechanical properties has also been discussed.

Abstract: The nanostructured titanium was fabricated via the surface mechanical attrition treatment (SMAT) process and the effect of nano-crystalline structure on the biomechanical and biocorrosion properties were studied. It was found that the Young’s modulus of nanostructured Ti decreased significantly and thus the biomechanical property was improved. The electrochemical results revealed that the corrosion resistance of Ti became worse after SMAT process, which is contributed to the higher activation of the nanostructured surface.