Study on Forming Processes for Laser Brazing of Multilayer Diamond Grains and Ni-Cr Alloy

In order to realize the layer-by-layer laser brazing of multilayer diamond abrasive particles, the multilayer laser brazing process of Ni-Cr alloy and diamond abrasive particles was studied systematically, from single channel scanning to single layer scanning and then to multilayer scanning. The brazing channel and layer of cross section shape characteristic parameters were extracted, the brazing layer section forming parameterized evaluations was carried out. Combined with the brazing layer surface morphology, the brazing layer composite forming characteristics was evaluated and discussed, the influence of brazing process parameters on forming was studied. The results show that the laser power and scanning speed are the important factors affecting brazing forming. They affect the degree of fusion of alloy powders, molten pool width, and further affect the dispersion state of diamond and performance that diamonds are infiltrated and wrapped by solders, finally affect the smoothness of the brazing layers. When the overlapping rate between channels is as 30%~40%, the brazing forming quality is better. In the reverse scanning strategy, the number of scanning channels is as 10, the fixed laser power is as 700 W, the scanning speed is as 15 mm/s, the spot diameter is as 1.5 mm, the overlapping rate is as 30%, the laser brazing of multilayer abrasives is realized, the filler metal to the diamond infiltration package is sufficient, the middle area of the brazing layer is smooth and continuous, the overall forming quality is good. © 2021, China Mechanical Engineering Magazine Office. All right reserved.