Effect of Titanium Content on the Microstructure and Mechanical Properties of Tungsten-Titanium Alloy

Tungsten heavy alloys (WHAs) with four different titanium contents (0.5%, 1.0%, 1.5%, 2.0%, wt.%) were prepared by powder metallurgy. The influence of titanium content on the microstructure and mechanical properties under high strain rates were investigated. The results show that the titanium particles disperse in the matrix with different morphology and the main effective element is the diameter of the titanium particles. There are lots of micro holes in the titanium particles when the diameter of titanium particles is larger than 20 mu m. The titanium particles do not dissolve in the matrix during the sintering process and the interfaces between titanium and tungsten, titanium and matrix are good. The results of Hopkinson Striker Bar indicate that the dynamic compressive strength is highest when the content of titanium is 0.5% and the strength has little change as the content of titanium increases from 1.0% to 2.0% under 3700 s(-1) strain rate. In the WHA with 2.0% titanium content, the adiabatic shear banding (ASB) is the main deformation mode and the titanium in the ASB is fragile, the temperature of thermal softening area is higher than that of the traditional WHAs because of the existence of titanium particles. The addition of titanium in the WHAs improves the adiabatic shear banding susceptivity