静电分离去除高温合金粉末中非金属夹杂物

摘要

用人工方法把不同粒度的Al2O3颗粒掺入到粒度为50~100μm的洁净镍基高温合金粉末中，采用静电分离(ESS)方法去除粉末中的Al2O3颗粒，研究ESS工艺参数对Al2O3颗粒去除效果的影响以及在最佳工艺参数条件下去除不同粒度 Al2O3颗粒的效果。结果表明，电晕电极电压和金属辊筒的转速影响 Al2O3颗粒的去除效果。ESS最佳工艺参数为：电晕电极电压40 kV，金属辊筒转速50 r/min。在该工艺参数条件下，不同粒度Al2O3颗粒的去除效果不同，粒度为100~150μm的Al2O3颗粒的去除效果最佳，去除率为83.3%，去除Al2O3颗粒的最大尺寸为200μm。对单个非金属夹杂物颗粒的受力分析表明，去除非金属夹杂物的最佳尺寸 dc与最大尺寸 dmax之间存在dc=2/3dmax的关系，计算值与实验结果相吻合。%Mixed powder was prepared by adding Al2O3 particles with different size into high temperature alloy powder sized 50−100μm in diameter. Such mixed powder was treated by electrostatic separation (ESS) with different processing parameters and the treated powder was observed under stereoscope to determine removing effects of Al2O3 particles. The results show that the removing effect is enhanced with increasing electrical corona electrode voltage and decreasing rotating rates of drum. The ideal removing effect is obtained under electrical corona electrode voltage of 40 kV and drum rotating rates of 50 r/min, which shows that ESS can effectively remove 76%of Al2O3 particles under 200μm and 83.3%of Al2O3 particles in the range of 100−150μm in diameter. Mechanical analysis of single Al2O3 particle shows that ESS has different removing effects on Al2O3 particles with different size. There exists an optimum Al2O3 particles size dc, and the maximum Al2O3 particles size of 200μm for the removing effect. It is confirmed by the calculation and experiment that the relationship between dc and dmax is dc=2/3dmax.