再生WC-Co复合粉及高耐磨性硬质合金涂层的制备

Preparation of recycled WC-Co composite powder and high wear resistance cemented carbide coating

以WC-6Co废旧硬质合金块体和Co_3O_4粉末为原料,采用氧化-还原碳化法制备再生WC-12Co复合粉,将复合粉经过造粒和热处理制备再生热喷涂喂料,进而采用超音速火焰喷涂(HVOF)制备再生WC-Co硬质合金涂层,比较再生硬质合金涂层和商业购买热喷涂喂料制备涂层的显微组织、耐磨性及其机制。结果表明:当配碳量为16.70%(质量分数)时,再生复合粉的碳含量适中;制备的再生热喷涂喂料由WC和Co相组成,热喷喂料球形度好,粒径分布均匀,平均粒径为23μm;再生WC-12Co硬质合金涂层的结构致密,WC晶粒尺寸分布均匀。与商业化热喷涂粉制备涂层显微组织和性能相比,再生涂层的磨粒磨损性能明显优于商业喷涂粉制备涂层的,其根本原因是两者的磨损机制不同。

Using the cemented carbides WC-6Co scraps and Co3O4 powder as the raw materials,the recycled WC-12 Co composite powder was prepared by a short-term recycling technique which contains the oxidation and reductioncarbonization procedures.The thermal spray feedstock powder was fabricated by the process consisting of spray drying and heat-treatment.The recycled WC-Co cemented carbide coating was fabricated by high velocity oxy fuel（HVOF）method.Moreover,the microstructure,wear resistance and its mechanism of the coating prepared by the recycled composite powder and the commercial feedstock powder were compared.The results show that when the carbon addition is 16.7%（mass fraction）,the recycled WC-Co composite has the appropriate carbon content.The fabricated feedstock only contains WC and Co phases,with homogeneously distribution of spherical particles and average particle size of 23μm.The recycled WC-12 Co coating has a high density and a homogeneous WC grain distribution.Compared the microstructure and properties of the coating fabricated by commercial feedstock powder,the recycled coating has better wear resistance,which is caused by different wear mechanisms.