The Influence of Ti Raw Materials on The Microstructure and Properties of W-Ti Alloys

To investigate the influence of raw material powder on the structure and performance of sintered alloy，the W-Ti alloy with a Ti content of 10 wt.% was synthesized using a combination of high-energy ball milling and vacuum hot-pressing sintering process, incorporating different types and shapes of titanium raw materials. The phase composition, microstructure morphology, grain size, density, and hardness characteristices of the W-Ti alloys were analyzed using X-ray diffractometer, scanning electron microscope, and Vickers hardness tester. The research revealed that only black Ti-rich phase β1(Ti,W) and gray W-rich phase β2(Ti,W) were presented in W-Ti alloys synthesized from TiH2 powders, irregularly shaped Ti powders, and spherical Ti powders. Furthermore, all alloy samples demonstrated a density exceeding 99%, satisfying the requirements of high-performance target materials. Variations in physicochemical properties of different titanium raw materials, resulted in differences of the distribution and particle size of the Ti-rich phase β1(Ti,W) within the microstructures of the W-Ti alloy. Notably, the W-Ti alloy sample prepared by TiH2 powder as the titanium raw material exhibited optimal performance, characterized by a uniform distribution of the Ti-rich phase β1(Ti,W) and fine grain size. The diffusion rate between tungsten and titanium elements is higher, resulting in an increased solid solubility between them. Simultaneously, there were significant enhancements in both density and mechanical properties of the alloy. These results indicate that by employing variations in the Ti raw material, it is feasible to achieve controlled phase composition and properties of W-Ti alloys.