采用氧化锆做绝缘阴模材料，设计研制能对压制中的粉末施加冲击电流的模具。研究电容组在不同的充电电压下，对处于不同压制压力下的汽车带轮用粉末瞬时放电，当电能以冲击电流的形式通过后，可引起压坯密度的变化。实验结果表明，施加冲击电流后，压坯密度增加，充电电压越高或粉末压坯初始密度越低，冲击电流对压坯密度增长的贡献越大。冲击电流作用后压坯温度升高，直径发生收缩，说明压坯密度增加是冲击电流的热效应与电磁效应共同作用的结果。%The pressing mould with die made of insulating material of ZrO2 was developed to apply surge current to compaction of powders using for automobile parts. Tests were conducted by using the capacitor bank under conditions of different charged voltages and different pressures. The surge current produced by discharging from the capacitor bank was passed through the steel powders as soon as it was compacted. It is found that the density of powder parts increases as surge current is applied to compaction of steel powders. Higher the voltage is or lower the part’s initial density is, greater the contribution of surge current for the density increase of powder part is. The test results show that the temperature increases and the diameter contracts as surge current is applied to the compacted part. The thermal effect and electromagnetic effect are main factors that affect the density of powder parts.
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