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

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.

Key words:Continuous brazing; Ultra-high frequency induction heating; Interfacial microstructure; Residual stress