铜基预钎焊金刚石锯片的界面分析及其性能研究

采用Cu-Sn-Ti钎料利用氩气保护高频感应钎焊对金刚石磨粒进行预钎焊处理。采用热压烧结工艺制作常规金刚石锯片、镀钛金刚石锯片和磨粒预钎焊金刚石锯片,并进行对比切割实验。通过三点抗弯实验测试上述三种节块的强度,并使用扫描电镜分析预钎焊金刚石磨粒界面和锯片节块断口的微观组织结构。结果表明:预钎焊金刚石磨料界面处存在元素的扩散现象并形成化学结合,且Cu-Sn-Ti钎料对金刚石磨粒的热损伤小;预钎焊金刚石节块的抗弯强度高于镀钛金刚石节块和常规金刚石节块;钎焊金刚石锯片刀头中金刚石与胎体之间同样存在元素的扩散现象,胎体与金刚石磨粒形成化学冶金结合;相同加工条件下,预钎焊金刚石锯片的切削效率相比于镀钛金刚石锯片和常规金刚石锯片分别提高7%和18%。

Interface analysis and performance evaluation of the Cu-based pre-brazed diamond saw blade

Based on high-frequency induction brazing technology with argon atmosphere protection brazing pretreatment was conducted with diamond grits using Cu-Sn-Ti alloy solder. Conventional diamond saw, Ti-coated diamond saw and pre-brazed diamond saw were made by powder metallurgy sintering technology and then conducted with a comparative cutting test. Bending strengths of three chunks were tested by three-point bending experiments, while pre-brazed diamonds＇ surface and micro- organization across section of diamond saw blade were analyzed by SEM. The results showed that metallurgical bonding was established through a cross-diffusion in the interface of the pre-brazed diamond and Cu-Sn-Ti alloy solder caused smaller thermal damage. And the bending strength of pre-brazed diamond saw blade was higher than that of Ti-coated diamond saw blade and conventional diamond saw blade. Besides, element cross-diffusion phenomenon occurred between metal matrix with diamond, then metal matrix and diamond grits formed metallurgical bond. Under the same processing conditions, compared with those of Ti-coated diamond saw and conventional diamond saw, the cutting efficiency of pre-brazed diamond saw increased by 7% and 18% respectively.