Oxidation resistance and phase constituents in the brazing interface of WC–TiC–Co hard alloys

The oxidation resistance and phase constituents in the brazing interface of WC–TiC–Co hard alloys have been researched by means of brazing inside a furnace, the scanning electron microscope (SEM) and the X-ray diffraction test, etc. The test results have indicated that a brazing joint in which the interface combines excellently can be obtained by using Cu–Zn–Ni brazing filler alloy, and controlling the heating temperature to 940–960 °C and the holding time 10–15 min employing a suitable post-heat measure. The interface of the hard alloy and the brazing filler alloy is in a good condition. The interface zone consists of WC, TiC, and CuZn (α-phase). There are no micro-cracks, inclusions, etc., near to the brazing interface. The interface zone is formed by the mutual diffusion of elements in the hard alloy and the brazing alloy under the condition of high temperature.