Microstructure and properties of W–4.9Ni–2.1Fe heavy alloy with Dy2O3 addition

Abstract

The W–4.9Ni–2.1Fe–xDy2O3 heavy alloy was fabricated by high-energy ball milling and spark plasma sintering (SPS) technique, and the microstructure, mechanical and friction behavior and anti-corrosion ability were investigated by scanning electron microscope (SEM), Rockwell hardness tester, X-ray diffraction (XRD), reciprocating friction and wear tester, electrochemical station, etc. The results show that the trace Dy2O3 particles, which mainly distributes in the W–M (tungsten-matrix) interface and the tungsten matrix phase, can dramatically decrease the tungsten grain size and the amount of O and P impurities aggregating in the interface, promote the γ-(Ni, Fe) bonding phase and tungsten particles uniform distribution, and increase the relative density, hardness, and wear and corrosion resistance properties. But the excessive Dy2O3 addition can make the inhibition effect weaken, resulting in the decrease in the comprehensive performances of the alloy. So, the amount of Dy2O3 should be appropriate. When the adding amount of Dy2O3 particles is 0.7 wt%, the comprehensive performances of the heavy alloy are the best.