(1. 中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室， 長沙 410083；
2. 中國原子能科學(xué)研究院， 北京 102413)
摘 要: 對以管式爐碳熱還原法制得的平均粒度為20.4μm的碳化硼粉進(jìn)行了氣流粉碎實(shí)驗(yàn)。 結(jié)果表明： 隨著粉碎次數(shù)增加， 粒度迅速下降，其平衡粒度達(dá)到0.45μm， 遠(yuǎn)小于相應(yīng)條件下普通球磨的4μm，振動(dòng)球磨的2μm； 可避免球磨筒和球的磨損對粉末的污染， 而且能連續(xù)作業(yè)， 生產(chǎn)率高；對這種原粉粉碎4次是適當(dāng)?shù)模?可得到約0.6μm的細(xì)粉， 進(jìn)一步增加粉碎次數(shù)其粒度降低不大， 但能耗大大增加。 對氣流粉碎機(jī)理進(jìn)行了探討，氣流粉碎既有很強(qiáng)的沖擊粉碎作用， 又有很強(qiáng)的摩擦粉碎作用， 哪一種機(jī)制起主導(dǎo)作用， 取決于進(jìn)粉粒度： 開始時(shí)粉末粒子較粗， 以沖擊粉碎為主， 經(jīng)過數(shù)次粉碎之后，粒子較細(xì)， 以摩擦粉碎為主； 在粉碎之初， 沖擊粉碎對粉末的細(xì)化， 即對粉末平均粒度的降低， 起決定性的作用； 隨著粉末的細(xì)化， 摩擦粉碎對粉末平均粒度降低的貢獻(xiàn)增加。
關(guān)鍵字: 碳化硼粉；超細(xì)粉； 氣流粉碎； 球磨
boron carbide powder
（1. State Key Laboratory for Powder Metallurgy,
Central South University, Changsha 410083, China;
2. China Institute of Atomic Energy, Beijing 102413, China）
Abstract:The raw powder of boron carbide with a particle size of 20.4μm fabricated by carbon reducing boron oxide in tube furnace was comminuted by air flow attrition. It is concluded that the mean particle size decreases rapidly with the increase of times of air flow attrition. The equilibrium particle size of 0.45μm obtained by it is much less than that by ball mill (4μm) or by vibratory mill (2μm). This method is also a continuous operation process with a higher productivity, and it will not lead to pollution from the wear of balls with jar. The experiment proves that a mean particle size of 0.6μm can be obtained by 4 times attrition, increasing the times further, the particle size decreasing is very limited, but the energy consumption increases much. The mechanisms of air flow attrition are also dealt with. Both impaction and grinding mechanisms are presented in this process. Which one is the dominant one depends upon the particle size of powder feeding into the air flow attritor. At first, the powder is coarser, the momentum of particles is higher, the impaction is the dominant factor; after several times of attrition, the powder is finer, the grinding becomes important. At the same time, a conclusion is also gained: at the beginning the impaction plays an important part in the powder refining; when the particle becomes finer, the contribution of grinding increases.
Key words: boron carbide powder; superfine powder; air flow attrition; bal
