Microstructure and mechanical properties of titanium alloy / zirconia functionally graded materials prepared by laser additive manufacturing

Abstract

The titanium alloy/zirconia functionally graded materials can greatly improve the hardness and wear resistance of titanium alloy, thus greatly enhance work life of titanium alloy. In this paper, the titanium alloy (Ti6Al4V)/zirconia functionally graded and non-functionally graded block were prepared by laser additive manufacturing to compare the microstructure evolution, elements distribution. The results indicated that the Ti6Al4V microstructure in the functionally graded block present the fine lath with the zirconia increasing. Compared to element distribution in the non-functionally graded block, the microstructure distribution in the functionally graded block altered from smooth and linear to nonlinear, and the elements transition is more stable and uniform. Microhardness in the functionally graded block increases with the zirconia increasing, and its variation trend agreed with the lever principle of composite mechanical properties. The wear loss was reduced with the zirconia increasing, and it was well conformed to the fitted function 1.09 × 10−2x-0.082. Also, the wear mechanism was mainly abrasive wear as the zirconia content rises in the functionally graded block, this was not like the mechanism of both abrasive wear and adhesive wear in the non-functionally graded block.