(1. 中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083；2. 湖南頂立科技有限公司，長沙 410111)
摘 要: 以碳酸鈷為原料，采用氫氣還原法在帶式無舟皿連續(xù)還原爐中制備超細球形鈷粉。考察還原溫度和還原時間對鈷粉粒度的影響。結(jié)果表明，在420~460 ℃還原180 min左右，可以制備費氏粒度為0.9 μm左右的超細球形鈷粉。采用二氧化碳氣體鈍化處理技術(shù)降低了鈷粉的氧含量。采用制備的鈷粉為超細晶粒硬質(zhì)合金的粘結(jié)劑，用低壓燒結(jié)工藝制備出鈷相高度分散、晶粒均勻的超細晶粒YG10硬質(zhì)合金。其晶粒度為0.4 μm，矯頑磁力達38.0 kA/m，硬度大于93.0 HRA，抗彎強度高于3 700 MPa。
關(guān)鍵字: 超細球形鈷粉；氣體鈍化；超細晶粒硬質(zhì)合金
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;2. Hunan Denli Technology Co. Ltd, Changsha 410111, China）
Abstract:Ultra-fine cobalt powder was prepared by the reduction of carbonate using a belt continuous boat-less reducing furnace in hydrogen. The influences of reduction temperature and time on the particle size of cobalt powder were studied. Ultra-fine spherical cobalt powder with particle size of around 0.9 μm was prepared at 420−460 ℃ for 180 min. The influence of CO2 passivation treatment on the oxygen content of cobalt powder was discussed. Ultra-fine WC-10Co cemented carbides were prepared by vacuum/pressure sintering technology using the obtained cobalt powder as raw binder material. YG10 ultra-fine cemented carbide was prepared with uniform distribution of cobalt phase, homogeneous grain size of around 0.4 μm, hardness equal to HRA93.0, bending strength equal to 3 700 MPa and coercive force equal to 38.0 kA/m.
Key words: ultra-fine spherical cobalt powder; CO2 passivation treatment; ultra-fine cemented carbides
