钎焊金刚石磨粒剪切强度评价研究

Evaluation study of the shearing intensity of brazed diamond grits

钎料与金刚石磨粒结合强度的测定与评价是钎焊金刚石工具研究与应用中的关键性问题。文章提出一种新的测试方法,通过剪切试验测试单颗金刚石磨粒的剪切破坏力大小,结合对破坏磨粒的微观分析,对结合强度进行评价。结果发现钎焊金刚石磨粒在受剪切力时,一般有2种破坏形式,分别为脱落、折断。钎焊时间和真空度对结合强度影响明显。在制备钎焊金刚石工具时,应该选用高级别的金刚石磨粒,高真空环境下进行高频感应钎焊金刚石磨粒较为有利。

Evaluating and measuring the interfacial bonding strength between filling alloy and diamond grits is a key issue in the study and application of brazed diamond tools. A new method for testing the bonding strength is proposed. The shearing load of single diamond grit brazed under different brazing conditions is measured by shearing experiment. Microscopic observation of the broken grits shows that the diamond grits are destructed in two modes when sheared： pull-out and fracture. It is evident that the brazing time and vacuity affect bonding strength. It is proposed that when preparing brazed diamond tools advanced diamond grits be used and diamond grits be brazed under high vacuity.