The Fundamental Research Of The In-situ Synthesized Tungsten Carbides Reinforced Composite Coating

As a typical boride ceramics, WC ceramics have become a researched hot point because of its high melting point, good chemical stability, high hardness and good resistance to abrasion. The WC granule is in-situ synthesized during the reaction of the alloy powders employing the TIG powder surfacing.The thesis adopts abrasive wear test for main trial method, apply the hardness tester, metalloscope, the scanning electric mirror, energy spectrum analysis instrument, abrasive wear tester and other test equipment, to the performance of the testing sample that make to have progress analysis test. The microstructure and morphology of the tungsten carbide coating is observed and analyzed. The tungsten carbide coating is composed of solid solution and dispersion hard phase such as carbides and borides. The elements of both the coating and the substrate diffuse to each other. The excellent metallurgy bonding is formed between the coating and the substrate.The composite coating's hardness is much higher than the base metal hardness,in the tungsten powder and silicon carbide for the preparation of the composite coating, base metal, the average hardness of 215 HV, coating the hardness of up to 824 HV;in the iron and graphite to tungsten for the preparation of the composite coating, base metal, the average hardness of 172 HV, coating the hardness of up to 698 HV;in the iron and silicon carbide tungsten preparation for the composite coating, base metal, the average hardness of 252 HV, coating the hardness of up to 665 HV;in the iron and boron carbide tungsten preparation for the composite coating, base metal, the average hardness of 202 HV, coating the hardness of up to 882 HV;in the tungsten powder and boron carbide for the preparation of the composite coating, base metal, the average hardness of 193 HV, coating the hardness of up to 897 HV.At room temperature abrasion conditions, tungsten and silicon carbide powder was prepared samples of the best wear resistance, it is 2.24 times of the comparative sample;tungsten iron and graphite materials for the preparation of the sample,the wear-resistance of which is 1.82 times of the comparative sample;tungsten iron and boron carbide for the preparation of the wear resistance of the sample is 1.15 times that of the comparative sample; boron carbide and tungsten powder was prepared samples of the wear-resistance is 1.16 times that of the comparative sample; tungsten iron and silicon carbide for the Preparation of the samples of the worst wear resistance is 0.84 times that of the comparative sample.The results of the thesis show that we can get good performance of high-temperature coating by heating with TIG, which provides a theoretical foundation for the industrial practical application of WC composite coating.