Ni-Cr合金钎焊单层金刚石砂轮界面结构的研究  

A Research on the Framework of Organization of Brazed Mono-layer Diamond Grinding Wheel with NiCr Alloy

作　　者：武志斌[1] 徐鸿钧[1] 姚正军[1] 肖冰[1] 傅玉灿[2] 

机构地区：[1]南京航空航天大学机电学院,江苏南京210016 [2]中国科技大学材料设计与材料力学性能开放实验室,安徽合肥230001

出　　处：《应用科学学报》2002年第1期10-13,共4页Journal of Applied Sciences

基　　金：国家自然科学基金资助项目 ( 5 9675 0 5 7)

摘　　要：以 Ni Cr合金粉做钎料适当控制钎焊工艺条件 ,成功研制了单层钎焊金刚石砂轮 .利用扫描电镜和 X射线能谱 ,结合金相及试样逐层的 X射线衍射结构分析 ,剖析了 Ni Cr合金与金刚石和钢基体钎焊界面的微区组织结构 ,揭示了 Ni Cr合金对金刚石和钢基体的浸润性及钎焊机理 .钎焊过程中 Ni Cr合金中的 Cr元素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 Cr7C3;在钢基体结合界面上 Ni Cr合金和钢基体中的元素相互扩散形成冶金结合 .这是实现合金层与金刚石及钢基体之间都有较高结合强度的主要因素 。We have successfully developed a brazed mono layer diamond grinding wheel with NiCr alloy under Ar atmosphere. SEMEDS microanalyses have shown that during brazing the chromium present in the alloy segregated preferentially to the surface of the diamond to form a chromium rich reaction product. Xray diffraction revealed that the wetting and bonding behavior on the diamond surface by NiCr alloy melt is realized through Cr 7C 3 which is produced by interaction between Cr atoms of NiCr alloy and C atoms of the diamond surface at elevated temperatures. The analyses also revealed that the bond between the alloy and the steel substrate was established through a cross diffusion of iron and chromium and the formation of (Fe x Cr y )C type carbides. Finally a grinding test showed that the wear modes of such a brazed grinding wheel were mainly grit fracture and attrition rather than grit dislodgment from the bond.

关 键 词：NI-CR合金 钎焊 单层金刚石砂轮 界面结构 镍-铬合金 

分 类 号：TG743[金属学及工艺—刀具与模具]