Interfacial microstructures and Grinding performance of Synthetic Diamond Grits brazed by Cu-22Sn-3Cr Alloy. Issue 1 (1st February 2022) - Gao, Lihua
Abstract: To ensure the reliable bonding and low thermal damage of brazed diamond grits, a Ni-free Cu-Sn-Cr filler alloy was developed based on our previous study. Interfacial microstructure of diamond grits brazing used by Cu-22Sn-3Cr (in wt. %) filler alloy at 950 °C for 5, 10, 20, and 40 min were systematically investigated. Only Cr7 C3 was generated at the interface between diamond and Cu-22Sn-3Cr alloy, and the thickness of Cr7 C3 was increased after extended brazing time. The grinding performance of diamond tools brazed using Cu-22Sn-3Cr alloy has fewer ratios of diamond grits with breakage and fall-off failures and thus was found to be superior to that brazed by Ni-14Cr-10P filler alloy. In addition, alloy composition has a more significant influence than brazing time on the interfacial microstructure and mechanical behavior of brazed diamond grits; and the higher mechanical behavior of diamond grits brazed using Cu-Sn-Cr filler alloy is proved to be closely related to the low solubility of C in Cu-Sn-based alloy. Results obtained in this work are also crucial for developing a diamond brazing technique to fabricate diamond-related materials and devices.