真空条件下钎焊单层金刚石砂轮的研究

Experimental Investigation of Brazing Monolayer Diamond Grinding Wheel under Vacuum Atmosphere

单层高温钎焊超硬磨料砂轮具有电镀砂轮无法比拟的优异磨削性能 .在真空条件下用Ni Cr合金做钎料进行了钎焊单层金刚石砂轮的实验研究 ,实现了金刚石与钢基体间牢固的化学冶金结合 .扫描电镜X射线能谱 ,结合X射线衍射结构分析发现 ,在金刚石界面上有Cr的碳化物Cr3C2 和Cr7C3存在 ,而钢基体结合界面上则生成有 (FexCry)C ,这应是金刚石与钢基体之间具有较高结合强度的主要原因 .通过磨削实验验证了金刚石确实有很高的把持强度 .

The distinct advantages of a brazed monolayer diamond grinding wheel over conventional electroplated diamond grinding wheel is introduced. The bonding between steel and diamond is carried out by induction brazing under vacuum atmosphere. The filled intermediate layer material is reactive Ni Cr alloy slice. The results show that chromium carbide(Cr 3C 2and Cr 7C 3)film is formed on the interface between the diamond and the filled intermediate layer, also(Fe x Cr y )C between steel surface and the filled intermediate layer. Finally a grinding test shows that the wear modes of such a brazed grinding wheel are mainly grit fracture and attrition rather than grit dislodgement from the bond.