Abstract

To achieve the brazed diamond tools with low thermal damage, the diamonds were brazed using Ni–Cr base filler metals containing up to 1.5 weight percent Nd. The microstructure of Ni–Cr base filler metals and the surface morphology and interfacial microstructure of brazed samples were characterized. The results show that by the addition of Nd, the microstructure of filler metals is obviously refined and becomes uniform. Meanwhile, Nd doping effectively reduces the graphitization degree and thermal residual stress of brazed diamonds. In addition, a variety of carbides (such as Cr₃C₂, Cr₇C₃, and SiC) which have low hot cracking tendencies are formed through occurring chemical/metallurgical reactions. The microstructural NdNi₄B particles contribute to reducing the thermal damage of the brazed diamonds after brazing. At a doping level of 1.0 wt.% of rare-earth Nd, the maximum residual stress of brazed diamond was reduced by 20% and the material removal increased by 45.1%.

中文翻译：

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Nd元素对Ni-Cr钎料钎焊金刚石显微组织和力学性能的影响

摘要

为了获得具有低热损伤的钎焊金刚石工具，使用含有高达 1.5 重量% Nd 的 Ni-Cr 基填充金属对金刚石进行钎焊。对 Ni-Cr 基填充金属的微观结构以及钎焊样品的表面形貌和界面微观结构进行了表征。结果表明，Nd的添加使填充金属的显微组织明显细化且变得均匀。同时，Nd掺杂有效降低了钎焊金刚石的石墨化程度和热残余应力。另外，通过发生化学/冶金反应形成具有低热裂纹倾向的多种碳化物(例如Cr ₃ C ₂、Cr ₇ C _3和SiC)。微观结构NdNi ₄ B颗粒有助于减少钎焊后钎焊金刚石的热损伤。当稀土 Nd 的掺杂量为 1.0 wt.% 时，钎焊金刚石的最大残余应力降低了 20%，材料去除率提高了 45.1%。