Effect of Y2O3 Addition on the Microstructure, Wear Resistance, and Corrosion Behavior of W-4.9Ni-2.1Fe Heavy Alloy

Abstract

Binding and particle phases are the two important parameters influencing materials properties. In this study, a series of novel W-4.9Ni-2.1Fe-xY2O3 (in weight%) alloys with different Y2O3 contents are prepared by secondary ball milling and spark plasma sintering (SPS) techniques to obtain uniformly distributed γ-(Ni, Fe) binding phases and finer grains. The microstructure, mechanical, wear resistance, and corrosion behavior of the sintered bodies with different Y2O3 were obtained by x-ray diffraction, scanning electron microscopy, Rockwell hardness tester, friction wear tester, and three-dimensional profile instruments. The results showed that a certain addition of Y2O3 led to refined grains and uniformed microstructures; but, if excessive, a weak grain refinement would be appeared. Moreover, the grain size tends to be stable with enhancing of the Y2O3 content. Considering properties such as density, hardness, compression yield strength, grain size, and uniform distribution of tungsten hard phase and γ-(Ni, Fe) binding phase, the comprehensive optimal amount of 0.7 wt.% of Y2O3 was attained for the alloy. Meanwhile, the SPS sintered body also exhibited the best friction, wear behavior, and corrosion resistance in 3.5% of NaCl solution.