(北京工業(yè)大學(xué)材料科學(xué)與工程學(xué)院，北京100124)
摘 要: 以WC-6Co廢舊硬質(zhì)合金塊體和Co3O4粉末為原料，采用氧化-還原碳化法制備再生WC-12Co復(fù)合粉，將復(fù)合粉經(jīng)過造粒和熱處理制備再生熱噴涂喂料，進(jìn)而采用超音速火焰噴涂(HVOF)制備再生WC-Co硬質(zhì)合金涂層，比較再生硬質(zhì)合金涂層和商業(yè)購買熱噴涂喂料制備涂層的顯微組織、耐磨性及其機(jī)制。結(jié)果表明：當(dāng)配碳量為16.70%(質(zhì)量分?jǐn)?shù))時，再生復(fù)合粉的碳含量適中；制備的再生熱噴涂喂料由WC和Co相組成，熱噴喂料球形度好，粒徑分布均勻，平均粒徑為23 mm；再生WC-12Co硬質(zhì)合金涂層的結(jié)構(gòu)致密，WC晶粒尺寸分布均勻。與商業(yè)化熱噴涂粉制備涂層顯微組織和性能相比，再生涂層的磨粒磨損性能明顯優(yōu)于商業(yè)噴涂粉制備涂層的，其根本原因是兩者的磨損機(jī)制不同。
關(guān)鍵字: 再生WC-Co復(fù)合粉；硬質(zhì)合金涂層；磨損性能；配碳量；熱噴涂粉末
（College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China）
Abstract:Using the cemented carbides WC-6Co scraps and Co3O4 powder as the raw materials, the recycled WC-12Co composite powder was prepared by a short-term recycling technique which contains the oxidation and reduction- carbonization 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 23 mm. The recycled WC-12Co 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.
Key words: recycled WC-Co composite powder; cemented carbide coating; wear resistance; carbon addition; thermal spray feedstock
