基于钎料粒度匹配机理的Ni-Cr合金钎焊金刚石的研究

Brazing Diamond by Ni-Cr Alloy Based on Particle Size Matching Mechanism

为解决钎焊金刚石工艺中钎料层厚度均匀性难以控制以及钎料用量与磨粒匹配困难的问题,建立了金刚石磨粒与钎料合理钎焊的几何模型,得到了具有理想钎焊效果的金刚石与钎料粒度匹配公式。运用匹配公式进行了钎焊金刚石新工艺实验,采用粒度为60目的球状颗粒Ni-Cr合金钎料对30目、50目、80目金刚石进行真空钎焊。利用扫描电子显微镜(SEM)、X射线能谱仪(EDS)分析金刚石钎焊微观形貌及焊接界面,结果表明:金刚石与Ni-Cr合金钎料界面有新碳化物生成,保证了钎焊性;30目与50目金刚石出露较好,表面无包覆;50目金刚石磨粒被良好包埋,且对金刚石有较好的爬升效果,平均包埋高度约为金刚石粒度的30%。

In order to solve the problems of diamond brazing processes that the thickness of the filler alloy layer was too hard to control and the amount of the filler alloy with grits was difficult to match,a reasonable brazed geometric model of the diamond and the filler alloy was built,and the formula for matching the size of the diamond and filler alloy with desired brazing effects was obtained. Applying the matching formula to carry out the test of brazing the diamond by the new process and using the spherical particles--Ni-Cr filler alloy--with the size of 60 mesh,the diamond of 30 mesh,50 mesh,80 mesh was vacuum brazed. The microstructure of the brazed diamond and the diamond-alloy interface were analyzed by the scanning electron microscope（ SEM） and X-ray energy dispersive spectroscopy（ EDS）,it shows that new carbide was formed into the interface to ensure the brazing. 30 mesh and 50 mesh diamond were well exposed without filler alloy coated on the surface. Diamond grit of 50 mesh was well embedded; good climbing effect along the diamond being observed,the average embedding height of the alloy is about 30% of the diamond grit.