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

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. [ABSTRACT FROM AUTHOR]