(南京航空航天大学 机电学院 江苏省精密与微细制造技术重点实验室，南京 210016)
摘 要: 采用Ni-Cr合金活性钎料，在高真空炉中实现金刚石与钢基体牢固的钎焊连接。借助扫描电镜、能谱分析仪和X射线衍射仪阐述真空钎焊金刚石的钎焊机理和界面特征，分析钎焊金刚石圆锯片在干式加工铸铁过程中磨粒的磨损特性。结果表明：在铸铁管加工方面，钎焊金刚石圆锯片表现出优越的高效切割性能，磨粒磨损主要以破碎为主，磨削高温引起切屑粘附在破碎磨粒表面；揭示在铸铁干式加工过程中金刚石磨粒表面出现轻微的石墨化磨损等现象；实验表明磨粒的强度依然能满足加工要求。研制出适用铸铁材料高效加工用的高锋利度、高强度、安全的钎焊金刚石切割片。
关键字: 金刚石圆锯片；铸铁管；真空钎焊；磨损机理；干式加工
（Jiangsu Key Laboratory of Precision and Micro-manufacturing Technology,
College of Mechanical and Electrical Engineering,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:Diamond grains were brazed onto steel (0.45%C) matrix in high vacuum furnace using Ni-Cr active powder filler alloy. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffracometry (XRD) techniques were applied to investigate the interface characteristics of brazing diamond abrasive crystals to steel substrate and the wear characteristics in dry cutting cast iron process. The results show that the brazing diamond saws have obvious advantages in terms of high efficiency cutting cast iron. The main wear of the grains is grits fracture from the brazed combined zone. The iron chips are adhered to the surface of the broken grains at high grinding temperature. The graphitization of diamond grits slightly occurred and the diamond strength is enough to meet the requirements of machining process when dry-cutting cast iron. The super sharp, high strength and safety brazed diamond saw was developed for the high efficiency machining cast iron materials.
Key words: diamond saws; cast iron pipe; vacuum brazing; wear mechanism; dry-cutting
