基于Ag-Cu-Ti钎料的超高频感应连续钎焊金刚石界面结构及残余应力

Interfacial Micrustructure and Residual Stress of Diamond Continuous Brazed with Ultra-high Frequency induction Using Ag-Cu-T

摘要:

采用Ag-Cu-Ti合金钎料基于超高频感应连续钎焊工艺实现了金刚石磨粒与大尺寸钢基体的连接，借助扫描电镜（SEM）对不同扫描速度条件下钎焊的金刚石界面微观结构形貌进行观察分析，采用Raman光谱对钎焊后金刚石的残余应力状态进行分析。结果显示：超高频感应连续钎焊金刚石表面TiC晶体的生成处于非平衡态的过程，TiC晶体形貌偏离理想的正八面体，呈球状和岛状。钎料层内部出现富Cu枝晶组织，而在45钢基体表层形成了马氏体组织。钎焊后的金刚石磨粒顶部受压残余压应力，最大值为500MPa，磨粒底部受到残余拉应力，最大值为150MPa，这中分布趋势与传统真空炉中钎焊方法获得的残余应力分布刚好相反。

Abstract:

Continuous brazing with ultra-high frequency induction was proposed to braze the monocrystalline diamond grains using Ag-Cu-Ti filler alloy. The interfacial microstructure and residual stress of the brazed diamond was investigated and analogized by scanning electron microscopy (SEM) and Raman spectroscope. The experimental results revealed the fact that the formation of TiC crystal was in non-equilibrium state during continuous brazing with ultra-high frequency induction. The morphology of the formed TiC appared granular and island-like structure, far away from the equilibrium state. A little dendrite with Cu-riched was observed in filler alloy, and martensite was formed near the surface of steel substrate. The maximum compressive stress in the brazed diamond was 500MPa at the top, while the maximum tensile stress is 150MPa at the bottom. This result was opposite to the residual stress distribution obtained by furnace brazing.