脉冲电流对Cu-40%Pb合金显微组织及性能的影响

Effect of Pulse Current on Microstructure and Properties of Cu-40%Pb Alloy

对Cu-40%Pb(wt)合金凝固过程施加脉冲电流,研究了合金显微组织变化及对力学性能的影响。结果表明,在未加脉冲电流情况下,显微组织中Pb元素偏析严重,组织不均匀;当施加300~900A/cm^(2)的脉冲峰值电流时,随着脉冲峰值电流密度的增加,显微组织中的富Pb相逐渐细小均匀。同时,随着脉冲峰值电流密度的增加,Cu-40%Pb合金显微硬度呈增加的趋势;未加脉冲电流时,显微硬度为29.2HV0.5,施加900 A/cm^(2)脉冲峰值电流时,合金的显微硬度增加至32.9HV0.5。合金的摩擦系数以及磨损量也随着脉冲峰值电流密度的增加呈降低的趋势。

A pulse current was applied to the solidification process of Cu-40%(wt)Pb alloy. The change of microstructure of alloy and its influence on mechanical properties were studied. The results show that the Pb element segregation in microstructure is serious and the microstructure is uneven without pulse current. When a pulse peak current of 300-900 A/cm^(2) is applied, the rich Pb phase in the microstructure becomes small and uniform as the pulse peak current density increases.Meanwhile, the micro-hardness of Cu-40%Pb alloy shows an increasing trend with the increase of electric pulse peak density.The micro-hardness is 29.2 HV0.5 without electric pulse applied, while the micro-hardnes increases to 32.9 HV0.5 when electric pulse peak density of 900 A/cm^(2) is applied. The friction coefficient and wear amount of the alloy show a decreasing trend with the increase of the electric pulse peak density.