Abstract: 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.

Key words: laser brazing, diamond, Ni-Cr alloy, multilayer, formability

摘要： 为实现多层金刚石磨粒逐层激光钎焊成形，从单道扫描到单层扫描，再到多层扫描，系统研究了镍铬合金与金刚石磨粒的多层激光钎焊工艺。通过提取钎焊道与层的截面成形特征参量，对钎焊层截面成形质量进行参数化评价，并结合钎焊层表面形态，对钎焊层综合成形特性进行评价和讨论，研究了工艺参数对钎焊成形的影响。研究结果表明：激光功率与扫描速度是影响钎焊成形的重要因素，不仅影响着合金粉末的熔合程度、熔池宽度，还影响金刚石的分散状态和钎料对金刚石的浸润包裹性，最终影响钎焊层的平整性。当道与道之间的搭接率为30%~40%时，钎焊成形质量较好。在采用逆向扫描策略，扫描道数为10、固定激光功率为700 W、扫描速度为15 mm/s、光斑直径为1.5 mm、搭接率为30%的条件下，实现了多层磨粒的激光逐层钎焊成形，钎料对金刚石浸润包裹充分，钎焊层中间区域平整连续，整体成形质量好。

关键词: 激光钎焊, 金刚石, 镍铬合金, 多层, 成形性