Effect of Composition on Microstructure and Dynamic Mechanical Properties of W-Ni-Cu Alloys

The effects of tungsten contents (80-88wt.%) and different Ni:Cu ratio (7:3-3:7 by weight) on microstructure and dynamic mechanical properties of W-Ni-Cu alloys were investigated. Results show that at the same sintering conditions, with tungsten content increasing from 80 wt % to 88 wt %, tungsten grains increase slightly. Spherical and more uniform tungsten grains distribute in matrix phase in 85W alloys with Ni:Cu ratio of 1:1 than that of 3:7 and 7:3. The results also show that the dynamic yield strength of W-Ni-Cu alloys goes up with tungsten content increasing, but keep similar deformation capability. With strain rate increasing in the range of 2600-4200s -1 , 85W displays strain rate softening effect. Adiabatic shear bands are formed at strain rate over 3200s -1 .