Cr Powder-Activated Induction Brazing of Diamond Grits with Ag–Cu–Zn Alloy

Abstract

Cr powder was used to activate the brazing of diamond grits with Ag–Cu–Zn alloy. The interfacial microstructure among the brazing alloy, the diamond grit, and the steel substrate is also examined by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction. It was found that Cr₇C₃ formed between diamond and Ag–Cu–Zn alloy was the main reason for improving the wettability of Ag–Cu–Zn alloy to the diamond and the strong bonding of diamond grit. A graphitization layer was formed on the surface of diamond under high temperature brazing. Bonding strength of the brazed diamond grits were also examined by a grinding test.

Keywords:

• Activated
• Ag–Cu–Zn alloy
• Bonding strength
• Carbide
• Cr₇C₃
• Cr powder
• Diamond grits
• Graphitization
• Grinding
• Induction brazing
• Interfacial microstructure
• Morphology
• Reaction layer
• Reaction mechanism
• Wettability

ACKNOWLEDGMENTS

The authors would like to thank Nature Science Foundation of China (59875014 and 50605009), Guangdong Nature Science Foundation (20000059), Guangdong Science Project (2005B10201027), and Guangdong Nature Science Foundation Team Project.