Interfacial analysis of vacuum brazing diamond/WC mixed abrasives with Ni[sbnd]Cr[sbnd]B[sbnd]Si active filler

Abstract

To develop a new generation of super–hard abrasive tools, diamond/tungsten carbide (WC) mixed abrasives were brazed onto AISI 1045 (0.45% C) steel substrate by using NiCrBSi active filler alloy in a high vacuum furnace. The brazing operation was executed at three different temperatures (1010 °C, 1030 °C, and 1050 °C), with different dwelling times (10 min, 15 min, 20 min, 25 min and 30 min). Scanning electron microscopy, energy dispersive spectroscopy and X–ray diffraction analysis were used to investigate the interfacial characteristics of the brazed diamond/WC mixed abrasives. The results of microstructural analysis showed that several chemical and metallurgical reactions occurred between NiCrBSi active alloy and diamond/WC mixed abrasives have occurred during the brazing process. Cr3C2 and Cr7C3 compounds were generated at the brazing interface of diamond and the active alloy. At the same time, the Ni2W4C and NiW and Cr7C3 phases were formed between WC and the active alloy. The bonding force test of the brazed joints was carried out and the results demonstrated that the newly developed brazing tools can be applied in the field of iron material processing with high efficiency and longer working life.