Effect of Nano-Y2O3 on the Microstructure and Properties of WC-Reinforced Ni-Based Composite Surfacing Layer.

Xingyu Ai,Zhengjun Liu,Zongxuan Zou,Zhenyu Wang

doi:10.3390/ma15051665

Abstract

In this study, a WC-reinforced Ni-based surfacing layer was prepared on Q235 steel plate by plasma arc welding. The effects of nano-Y2O3 with different contents (0 wt.%, 0.4 wt.%, 0.8 wt.%, 1.2 wt.%, and 1.6 wt.%) on the microstructure, phase composition, microhardness, and wear resistance of the surfacing layer were studied by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), microhardness test, and pin-on-disk test. The results show that the phase composition of the surfacing layer was γ-Ni, FeNi3 solid solution, WC, W2C, M23C6, M6C, Cr7C3, and other carbides. When the addition of nano-Y2O3 was 1.2 wt.%, it has a good improvement on microstructure grain refinement and carbide hard-phase increase. Compared with other contents, 1.2 wt.% nano-Y2O3 surfacing layer has the highest microhardness and the lowest friction coefficient and wear loss. At this time, the wear mechanism is abrasive wear accompanied by slight adhesive wear.

Highlights

Wear is one of the common failure modes of mechanical parts, and traditional steel materials find increasing difficulty in meeting the demands of special environments [1]
This is because an appropriate amount of Y2O3 can uniformly disperse the hard phase in the surfacing layer, refine the grain, improve the ability to resist dislocation slip and promote γ- Ni matrix forms a wearresistant skeleton with excellent wear resistance, which can effectively protect the surfacing layer from wear damage when cutting wear occurs between wear debris and matrix
After the addition of 1.6 wt.% Y2O3 (Figure 14e), adhesive wear marks and peeling pits appeared on the surface

Summary

Introduction

Wear is one of the common failure modes of mechanical parts, and traditional steel materials find increasing difficulty in meeting the demands of special environments [1]. The addition of some ceramic particles to the nickel-based powder enables the surfacing layer to achieve higher hardness, wear resistance, corrosion resistance, etc. WC is a hard phase commonly used in MMCs. WC powder has a high melting point, high hardness, good wear resistance, and good wettability with MMCs. WC reinforced nickel-based alloy surfacing layer has been widely used [18,19,20,21]. Zhao et al [28] prepared nickel-based coatings with nanoscale La2O3 by laser melting and found that the addition of La2O3 significantly refined γ- (Ni, Fe) dendrites, improving the hardness and wear properties of the coatings. Wang et al [29,30] investigated the microstructural characteristics of laser clad nickel-based alloy coatings with rare earth oxide CeO2 or La2O3. The effects of nano-Y2O3 content on macromorphology, microstructure, microhardness, and wear properties of the nickel-based WC (30%) surfacing layer were studied

Materials and Methods

Microhardness and Wear Resistance Analysis of the Surfacing Layer

Findings

Conclusions