恒温时间对PCD刀具焊接性能的影响

Effect of holding time on the brazing properties of PCD cutting tools

本文通过PCD复合片与YG8硬质合金的高频感应钎焊试验,研究了恒温时间对PCD刀具钎焊接头强度及钎缝宽度的影响,并用扫描电镜观察了钎焊接头的显微结构,用电子探针分析了接头界面元素分布情况。试验结果表明:随着恒温时间的增加,钎焊接头的剪切强度先增大后减小,而钎缝宽度先减小后增大。当恒温时间为16 s时,剪切强度达340 MPa,钎缝宽度仅有25μm。No2试样中钎料元素发生了不同程度的扩散,Mn元素的氧化和Zn元素的挥发不明显,C元素有一定程度的扩散,说明钎焊工艺参数选择合理。

In order to study the influence of holding time on shearing strength and width of the welding joint, hi - frequency induction brazing experiments with PCD compact and YG8 were carried out. The microstructures of brazing joints were observed by means of Scanning Electron Microscope （SEM）, and the distribution of elements on the intersection was analyzed using Electron Probe Micro Analyzer （EPMA）. It was found that the shearing strength of the brazing joint increased and then decreased along with the increase of holding time, while the brazing joint width decreased and then increased. When the holding time reached 16 s, the shearing strength reached the maximum which was 340 MPa, the joint width was as narrow as 25 μm. The elements of Sample No. 2 in the brazing joint diffused into the matrix to some extent. The oxidation of Mn and the vaporization of Zn were not obvious. There is some diffusion of C. All this indicates that our brazing process parameters are reasonable.