镁基汽车电池合金的锻造工艺及组织性能

Forging process and microstructure properties of Mg-based automotive battery alloy

采用不同温度进行了Mg1.8Al0.2Ni镁基电池合金的多向等温锻造工艺试验,并与锻造前的合金进行了显微组织、耐腐蚀性能和充放电循环稳定性的对比分析。结果表明:多向等温锻造工艺明显细化了合金晶粒,显著提高了合金的耐腐蚀性能和充放电循环稳定性;随着锻造温度从350℃增至450℃,Mg1.8Al0.2Ni镁基电池合金的内部组织先细化、后粗化,合金的耐腐蚀性能和充放电循环稳定性均先提高、后下降;与锻造前的合金相比,经350℃多向等温锻造后,Mg1.8Al0.2Ni镁基电池合金的腐蚀电位正移了32 mV,充放电循环20次后放电容量保持率增大了21%,合金的耐腐蚀性能和充放电循环稳定性均得到了显著提高。

The multi-directional isothermal forging process tests of Mg1.8Al0.2Ni Mg-based battery alloy were carried out at different temperatures,and the microstructure,corrosion resistance property and charge-discharge cycle stability were compared and analyzed with the alloy before forging. The results show that the multi-directional isothermal forging significantly refines the grains of alloy and improves the corrosion resistance property and charge-discharge cycle stability of alloy. With the increasing of forging temperature from 350 ℃ to 450 ℃,the internal microstructure of Mg1.8Al0.2Ni Mg-based battery alloy is first refined and then coarsened,and the corrosion resistance property and the charge-discharge cycle stability of alloy are first increased and then decreased. Compared with the alloy before forging,the corrosion potential of Mg1.8Al0.2Ni Mg-based battery alloy after multi-directional isothermal forging at 350 ℃ is positively shifted by 32 mV,the retention rate of discharge capacity increases by 21% after twenty charge-discharge cycles,and the corrosion resistance property and the charge-discharge cycle stability of alloy are significantly improved.