Microstructure Characterization and Wear-Resistant Properties Evaluation of an Intermetallic Composite in Ni-Mo-Si System.

Boyuan Huang,Chunyan Song,Yongliang Gui,Yang Liu

doi:10.3390/ma10020130

Abstract

Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni–Mo–Si system was fabricated by arc-melting process with commercially pure metal powders as starting materials. The chemical composition of this intermetallic composite is 45Ni–40Mo–15Si (at %), selected according to the ternary alloy diagram. The microstructure was characterized using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), and the wear-resistant properties at room temperature were evaluated under different wear test conditions. Microstructure characterization showed that the composite has a dense and uniform microstructure. XRD results showed that the intermetallic composite is constituted by a binary intermetallic compound NiMo and a ternary Mo2Ni3Si metal silicide phase. Wear test results indicated that the intermetallic composite has an excellent wear-resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases NiMo and Mo2Ni3Si.

Highlights

It is more and more challenging for traditional engineering steel materials to satisfy the gradually growing performance requirements for wear-resistant materials which service in serious environments [1,2,3]
A new intermetallic composite in a Ni–Mo–Si ternary system was designed based on the concept of the “in-situ” formation of multi-phase intermetallic composite and fabricated successfully using arc-melting method, which has a microstructure of binary intermetallic NiMo and ternary metal silicide Mo2 Ni3 Si
Ni–Mo–Si ternary system intermetallic composite has a dense andeutectic uniform microstructure whichNi–Mo–Si consists of primary dendrites, interdendritic matrix, remained

Summary

Introduction

It is more and more challenging for traditional engineering steel materials to satisfy the gradually growing performance requirements for wear-resistant materials which service in serious environments [1,2,3]. Materials 2017, 10, 130 multi-phase intermetallic composites could have a better combination of toughness and strength. The formation of metal silicide in a Ni–Mo–Si ternary system resulting from the addition of Si may be beneficial for the properties of intermetallic compounds by offering good creep resistance, low density, and wear-resistance [23,24]. A new intermetallic composite in a Ni–Mo–Si ternary system was designed based on the concept of the “in-situ” formation of multi-phase intermetallic composite and fabricated successfully using arc-melting method, which has a microstructure of binary intermetallic NiMo and ternary metal silicide Mo2 Ni3 Si. The purpose is to clarify the microstructure and wear-resistance of NiMo/Mo2 Ni3 Sicomposites with different Si content in chemical composition and some eutectic structure in microstructure. The worn surface morphologies and wear debris collected after wear tests were examined by scanning electron microscope (SEM)

Experimental Procedures

Results and Discussion

These that the 45Ni–40Mo–15Si materials are listed in

Conclusions