采用超高频感应钎焊工艺在不同扫描速度条件下对CBN磨粒与45钢基体实现钎焊连接。采用激光Raman光谱仪对钎焊后CBN的残余应力状态进行了检测分析,探讨了残余应力的形成机理,最后研究了超高频感应钎焊CBN砂轮的磨损特征。结果表明:钎焊CBN磨粒顶部受残余压应力,底部受残余拉应力,这种应力分布趋势与传统真空炉中钎焊方法获得的残余应力分布刚好相反。随着扫描速度增大,残余应力分布呈上升趋势,最大残余压应力约220 MPa,最大残余拉应力约160 MPa。为了使钎焊CBN磨粒不出现微裂纹,扫描速度不宜超过1 mm/s。缓进给深切磨削镍基高温合金GH_4169试验结果显示,钎焊CBN砂轮的主要磨损形式是磨耗磨损和尖角微破碎。
Ultra-high frequency induction brazing was proposed to braze the CBN grits and ANSI 45 steel substrate with different scanning speed. The residual stress of the brazed CBN grits was investigated through laser Raman spectrometer. The mechanism of residual stress induced in brazed CBN grits was discussed. The wear characteristic of the Ultra-high frequency induction brazed CBN wheel was studied at last. The results showed that the compressive stress in the brazed CBN located at the top, and the tensile stress at the bottom. This residual stress distribution feature was opposite to the results obtained by furnace brazing. With the increase of scanning speed, the residual stress is on the rise. The maximum compressive stress is 220 MPa, while the maximum tensile stress is 160 MPa. In order to avoid micro cracks on brazed CBN grit, it was advised that the scanning speed should be less than 1 mm/s. Creep feeding grinding test of GH4169 super-alloy showed that the wear form of the brazed grinding wheel was grain abrasion and micro- fracture.