基于不同母材的PDC钎焊强度的影响因素分析

随着聚晶金刚石复合片（PDC）钻头在复杂地层的应用范围不断扩大，对PDC复合片与钻头体材料的焊接强度要求越来越高，为了探究PDC复合片和不同钻头体材料的钎焊工艺，选用2种基体材料（胎体式和钢体式PDC钻头试样，以下简称胎体试样和碳钢试样）、2种钎料，采用火焰钎焊和高频感应钎焊，研究了钎焊温度、钎料、钎焊方式对PDC复合片和不同基体材料焊接性能的影响，得出了剪切强度随温度的变化曲线。同时，采用光学显微镜对PDC的焊缝断面进行了观测。结果表明，PDC复合片与胎体试样钎焊时，为硬质合金间的钎焊，钎料与母材润湿效果好，剪切强度值较高；PDC复合片与碳钢试样钎焊时，为硬质合金和异种材料间的钎焊，为了提高剪切强度，可适当提高钎焊温度或采用Ni含量高的钎料。

Analysis on the influence factors of brazing strength of PDC based on different base metal

With the continuous expanding of the application of PDC bit in complicated formation, the requirements for welding strength of PDC and substrate materials is increasingly high. In order to explore the brazing process of PDC compacts and different substrate materials, the PDC compact were brazed in the atmosphere with two substrate materials (the samples of matrix and carbon steel PDC bit, for short, the matrix specimen and the carbon steel specimen) and two brazing filler alloys, using flame brazing and high-frequency induction brazing. The influence of the brazing temperature, brazing materials and brazing mode on the welding performance of PDC compacts and different base materials was studied, the changing curve of the shear strength with temperature was obtained. At the same time, the brazing surface was observed using an optical microscope. The results show that when the PDC compact and the matrix specimen are brazed, it is brazing between the cemented carbide, the brazing solder can dip into base metal effectively and the strength of welded joint is high. When the PDC compact and the carbon steel specimen are brazed, it is brazing between the cemented carbide and the dissimilar. In order to improve the shear strength, the brazing temperature may increase appropriately or of brazing filler metal with high Ni content may be used.