Abstract: Based on the advantages of low energy inputs and small thermal influences during pulsed laser processing, which was applied to the brazing processes of diamond abrasive grains to realize the layer-by-layer brazing formation of multi-layer diamond abrasive grains. Through single-pass and single-layer pulsed laser brazing tests, the influences of processing parameters on brazing formation and diamond damage were studied, and better processing parameters were selected for multi-layer brazing tests. The results show that during the pulsed laser brazing processes, the changes of processing parameters mainly affect the brazing formation and diamond damage morphology by changing the peak power density and linear energy density. When the input energy density is insufficient, the brazing bead and the brazing layer are prone to molten balls, diamond accumulation, insufficient fusion, discontinuity, and unevenness; when the input energy density is too large, it is prone to diamond damage, the loss and escape of powder materials and diamond. When the line energy density is in 14~25 J/mm2 and the peak power density is in 5×105~1.5×106 W/cm2, good smoothness and good diamond morphology may be obtained. Under the parameters chosen from the scope of above parameters, the formation of multiple layer structure is realized by layer-by-layer brazing, and a better surface forming morphology and a lower diamond damage morphology are obtained. Bending test results of the multi-layer brazing sample show that the bonding strength between brazing layer and base metal is good, and the brazing layer stripping phenomenon does not appear.

Key words:  , pulsed laser, layer-by-layer brazing, planarization, diamond damage

摘要： 基于脉冲激光加工时的低能量输入和较小的热影响优势，将其应用到金刚石磨粒的钎焊过程中，以实现多层金刚石磨粒的逐层钎焊成形。通过单道及单层脉冲激光钎焊试验，研究了工艺参数对钎焊成形及对金刚石损伤的影响规律，并优选出较好的工艺参数进行了多层钎焊试验。研究结果表明：在脉冲激光钎焊成形过程中，工艺参数的变化主要通过改变峰值功率密度和线能量密度来影响钎焊成形和金刚石损伤形态。输入的能量密度不足时，钎焊道及钎焊层易出现熔融球、金刚石聚集、熔合不充分、不连续及不平整等现象；输入的能量密度过大时，易出现金刚石损伤、粉末材料及金刚石流失逃逸等现象。当线能量密度为14~25 J/mm2、峰值功率密度在5×105~1.5×106 W/cm2时，可得到平整性良好和金刚石磨粒形态良好的钎焊形貌，且在此参数范围内优选的参数条件下实现了多层结构的逐层钎焊成形，得到了较好的表面成形形态及较低的金刚石损伤形态。多层钎焊试块弯曲试验结果表明，钎焊层与基体之间具有较好的结合强度，未出现钎焊层剥离现象。

关键词: 脉冲激光, 逐层钎焊, 平整性, 金刚石损伤