Effect of CeSi2 addition on microstructures of brazed layers and interfacial characteristics of brazed diamonds with Ni Cr filler alloy

Abstract

The thermal damage of diamond is the key factor restricting the performance of brazed diamond tools with Ni-based filler. Hence, the Ni Cr filler alloy is modified by adding Ce element to reduce the graphitization and improve the mechanical properties of brazed diamond in this work. The results indicate that the microstructures of brazed layers with Ni Cr filler containing Ce element are obviously refined, and the brazed layer containing 2 wt.% CeSi 2 shows the better wear resistance with stable friction coefficient curve and low wear loss. Meanwhile, the brazed diamond with Ni Cr filler containing 2 wt.% CeSi 2 exhibits a higher exposure, and the Cr 3 C 2 on its surface is finer, which contributes to reduce the stress concentration and cracks formation at interface between diamond and filler. The Raman spectrum results show that the graphitization of brazed diamond is significantly weakened due to addition of CeSi 2 . The Ni Cr filler brazed diamonds containing 2% CeSi 2 remain relatively complete cutting edges and shapes after grinding test, showing the excellent wear resistance. Moreover, the calculation of elastic properties indicates that the in-situ formed CeNi 3 phase exhibits better ductility and plasticity, but lower hardness, and its formation is beneficial to improve the ductility and plasticity of brazed layer. • Diamond grits are brazed with Ni Cr filler containing different contents of CeSi 2 . • Microstructures of brazed layers containing CeSi 2 are refined. • Brazed layer containing 2 wt.% CeSi 2 exhibits the best wear resistance. • Graphitization of diamond brazed with 2 wt.% CeSi 2 -doped filler is weakened. • Brazed diamond with 2 wt.% CeSi 2 -doped filler presents superior mechanical performance.