On the Production of W–Fe–B Ternary Compounds by Self-propagating High-Temperature Synthesis

Abstract

In this study, one-step production of W2FeB2 and WFeB compounds from oxide raw materials was carried out through cost-effective and energy-efficient aluminothermic self-propagating high-temperature synthesis (SHS). Accordingly, the feasibility of SHS in the production of W2FeB2 and WFeB compounds was discussed. In addition, the selected SHS products of W2FeB2 were re-melted through arc melting to investigate the structure modification of W2FeB2 phase at high temperature. Prior to experimental work, raw material amounts, adiabatic temperatures, and phase diagram were calculated by FactSage™ software. The phase, microstructure, and compositional analyses were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), respectively. The formation of γ-Fe, FeB and orthorhombic W2FeB2 phases was detected for the samples that were mainly composed of WFeB, while W2FeB2-rich samples contained α-WB. Moreover, XRD analysis results suggested the formation of a trace amount of ternary W3FeB3 phase in the W2FeB2-rich samples. High-temperature structure modification of W2FeB2 (tetragonal) with arc melting was also successfully conducted. Vickers hardness test results were found to be in the range of 1007 to 2157 HV and WFeB containing samples possessed lower hardness than W2FeB2-rich samples. The experimental results revealed that SHS could be an alternative and promising feasible synthesis route for the production of W2FeB2/WFeB ternary borides.