Formation of Layer WC-(Co,Ni,Al) Structure on the Cutting Plate Surface of WC-7(W,Ti)C-10Co Cemented Carbide in the Contact Area with Ni3Al Melt

Abstract

It reported that a new type of the structure was found on the cutting plate surface of the WC-7(W,Ti)C-10Co cemented carbide of T5K10 brand after contact with the Ni₃Al melt at 1530°C in a vacuum, which includes external WC-(Co,Ni,Al) and intermediate WC-(W,Ti)C-(Co,Ni,Al) layers with varying chemical and phase composition by thickness. The maximum content and dimensions on the Co-based phase are characteristic of the structure on the boundary of the outer and transition layers, which by 1.7 and 2 times, respectively, exceed the similar indicators in the basic structure of this sample. The formation of such a structure occurs by the output of W, C and the Co-based phase from the volume on the surface of the plate and the subsequent absorption of it by N and Al from the Ni₃Al melt. It is shown that in the formed layer structure on the plate surface there is a residual microporosity but less than that in the basic structure outside the surface layer, which also decreased in comparison with the level of microporosity in the structure of the initial plate.