Effect of Cr on microstructure and properties of brazed diamond with Ni-based boron free solder

Abstract

In view of the problem that B element is easy to cause more hard and brittle phases in brazed diamond joints, a new type of Ni–Cr–Si–Cu–Sn boron free active solder was prepared, and the effects of Cr element on the microstructure of solder and the properties of brazed diamond were analyzed. The results show that Cr element can refine the solder grain and regulate the distribution of elements in the solder, which can improve the microhardness of the solder alloy. Excessive Cr addition will cause the melting point of the solder to increase and the wettability of the solder to decrease. In general, the boron free solder containing 15% Cr has the best performance, the grinding performance of brazed diamond is better, and Cr7C3 phases of various shapes appear at the joint, realizing the high-strength connection of the solder to the diamond.

Keywords

• brazing
• diamond
• new ni-based boron free solder
• active element
• mechanical property