Effect of aluminum powder on properties of induction braze coated diamond layers in atmospheric environment

Braze coating of diamond is an important technical method to improve the surface morphology and properties of materials. Due to the superhard characteristics of diamond, it is difficult to match the properties between diamond and brazing filler metal in braze coated layers. Effect of aluminum powder to nickel-based filler metals on microstructures and wear resistance of induction brazed diamond coating in the atmospheric environment was studied. The results showed that, addition of aluminum can reduce the porosity of the coating and improve its wear resistance due to in-situ formed Al₂O₃ phases. The deoxidation effect of active aluminum powder in induction braze coating and the wear resistance of in-situ oxide ceramics have been found in this paper. Al₂O₃ can also refine the microstructure of the brazing filler metals, modify the coating morphology and increase the coating thickness. In addition, it is clarified that the mechanisms of deoxidation of aluminum powder to reduce pores and the enhancement of Al₂O₃ hard phase to increase hardness and wear resistance.