等通道转角挤压法对Pb-Ag合金电极组织及电化学性能的影响

Effects of Equal Channel Angular Pressing Method on Microstructure and Electrochemical Properties of Pb-Ag Alloy Electrode

铅银合金作为湿法冶金的首选电极材料,但仍存在成本高、综合性能不佳及稳定性差等方面的不足。通过对铅银合金的大塑性变形,在不增加成本的基础上改善了合金综合性能。即,在模角为90°的模具中,对Pb-Ag合金以C路径进行等通道转角挤压,然后进行100℃保温1 h退火。对挤压后试样的显微组织、导电性及电化学性能进行了研究。结果表明:随着挤压道次的增加,晶粒不断细化,合金的综合性能也发生显著变化。与铸造合金相比,6道次挤压后的合金电极的电阻率减少32.6%,电极极化电位降低12.4%,能耗降低28.8%。因此,等通道转角挤压法可用于制备新型节能型电极。

Pb-Ag alloy is the preferred material for electrode in hydrometallurgy, but there still exist some disadvantages of high cost, poor integrative performance, bad stability and so on. On the basis of not increasing costs, the integrative performance of Pb-Ag alloy was improved by severe plastic deformation, Namely, Pb-Ag alloy was extrued by equal-channel angular pressing （ECAP） with C route in the die of die angle of 90°, and then annealing at 100 ℃ for 1 h was carried out. Microstructure, electrical conductivity and electrochemical properties of samples after ECAP were investigated. The results show that the grain is continuously refined, and the integrative performance of the alloy also changes significantly with the increase of the extrusion passes. Compared with casting alloy, the electrical resistivity, polarization potential and energy consumption of Pb-Ag alloy electrode after extrusion of 6 passes decrease by 32.6%, 12.4% and 28.8% respectively. Therefore, ECAP can be used to produce a new type of energy saving electrode.