Preparation of High Performance Cemented Carbide by Microwave Sintering

In a variety of sintering technology, microwave heating with heating speed, the overall heating, selective heating and non-thermal effects and other traditional heat conduction heating mode does not have the characteristics. Carbide (WC-Co) powder compact has a good coupling absorption effect on microwave, microwave penetration in the mixture in a large depth, so the microwave sintering technology to prepare hard alloy with the traditional heat conduction heating preparation

Way can not match the advantages. These advantages are manifested in the following aspects: 1, micro-high-performance wave heating fast, the integrity of not only can significantly shorten the preparation cycle and reduce the sintering temperature, simplify the process, and can be prepared microstructure uniform, Fine material. 2, due to the high energy efficiency of microwave and its environment-friendly features, so to lower costs and less environmental pollution to create greater economic value. 3, the characteristics of microwave heating is very conducive to the development of nano-ultra-fine crystal carbide, gradient carbide, carbide coating and other new high-performance cemented carbide. These advantages make the development of cemented carbide and microwave sintering technology combined into an inevitable trend.

University of Pennsylvania with the microwave sintering method successfully prepared WC-Co high performance cemented carbide. Compared with the traditional sintering method, microwave sintering can be in the lower sintering temperature and shorter holding time to get the same degree of contraction, sintered samples in the three dimensions of the same degree of contraction, and the traditional sintering in the vertical direction And the microwave sintered samples have more fine WC grains and more uniform Co phase distribution than the traditional sintered samples. The hardness is higher and the chemical corrosion performance is better. In addition, it was found that there was almost no W atom in the bonded phase of the microwave sintered sample, which was very different from the case where the mass fraction of the conventional sintered sample was about 20% W atom.