【摘要】 用活性钎料钎焊单层金刚石砂轮与传统电镀砂轮相比具有磨削锋利、寿命长等优异性能。利用 Ar气保护炉中钎焊的方法 ,用 Ni-Cr合金粉末做钎料 ,适当控制钎焊温度、保温时间和冷却速度 ,实现了金刚石与钢基体的牢固连接。利用扫描电镜和 X射线能谱 ,结合 X射线衍射结构分析 ,发现在钎焊过程中 Ni-Cr合金中的 Cr元素分离出在金刚石界面形成富 Cr层并与金刚石表面的 C元素反应生成 Cr3C2 和 Cr7C3,这是实现合金层与金刚石有较高结合强度的主要因素。重负荷磨削实验表明金刚石为正常磨损 ,没有整颗金刚石脱落更多还原

【Abstract】 The brazing of a monolayer of diamond grinding wheel with active filler metals can show distinct advantages over conventional electroplated diamond grinding wheel in terms of sharper grinding and longer life. The present study has shown that a commercially available Ni-Cr alloy can be used as an active filler material for brazing diamond grit. Furnace brazing was carried out in a current of argon.. SEM-EDS microanalyses have shown that during brazing the Cr present in the alloy segregated preferentially to the surface of the diamond to form a Cr-rich reaction product. X-ray diffraction revealed that the wetting and bonding behaviour on diamond surface by Ni-Cr alloy melt is realized through Cr 3C 2 and Cr 7C 3 which is produced by interaction between Cr atoms of Ni-Cr alloy and C atoms of diamond surface at elevated temperatures. Finally a grinding test showed that the wear modes of such a brazed grinding wheel were mainly grit fracture and attrition rather than grit dislodgement from the bond.更多还原