Microstructural Change of a Ti-10at%Mo-10at%Cr Alloy on Sintering Process

Titanium and its alloys have been widely used in automotive industry due to their high specific strength, excellent corrosion resistance, high temperature capability and low density. In this study, the microstructural changes of Ti-10at%Mo-10at%Cr alloy on sintering process was observed to clarify alloying behavior. The sample was fabricated using powder metallurgy process with two main operations on sintering process, ie sintering in a vacuum condition at temperatures of 1573K and furnace cooling with. Microstructures were observed by optical microscopy and scanning electron microscopy (SEM). The distribution of elements in the sample was analyzed using SEM - energy-dispersive X-ray spectroscopy (EDS). Micrograph of the samples after sintering process shows the microstructure of bright-circle structures, equiaxed structures, plate-like structures and pores. Composition of microstructures changed with the prolonging of sintering time. The microstructural change was due to diffusion of composing elements on sintering. The bright-circle and the equiaxed structure significantly decreased, while the plate-like structure increased, as sintering time increased. Moreover, the volume fraction of the pores slightly increased. On the other hand, mechanical properties of the sample, namely hardness was increased. This observations revealed that the sintering, which promotes the diffusion of alloying elements, have a significant influence on the microstructural changes.