Zn和SiC_p对挤压铸造镁合金组织和性能的影响

Influence of Zn Content and SiC_p Addition on Microstructure and Properties of Squeeze Casting Magnesium Alloys

根据微观结构及物相分析、静态失重法、极化曲线试验,研究了Zn及SiC_p对镁合金组织和性能的影响。结果表明,相比于Mg-8Zn-0.6Zr,Mg-12Zn-0.6Zr与SiC_p/Mg-12Zn-0.6Zr中Mg_7Zn_3相的含量及分布明显发生改变。对应的3种合金在90℃、3%的KCl溶液中的分解速率分别为2.30、5.62、7.24 mg·cm^(-2)·h^(-1)。分解过程中抗压强度随镁合金质量损失呈线性下降。分解速率提高的主要原因是α-Mg相的阳极溶解、微小粒子的脱离及腐蚀产物对分解过程无阻滞作用。

Effects of Zn content and SiC addition on structure and decomposition behavior of magnesium alloys were investigated by static weight loss, polarization curve and the micro-morphology characteriza- tion. The results indicate that the content and distribution of MgTZn3 in Mg-12Zn-0.6Zr and SiCp/Mg- 12Zn-0.6Zr are different from Mg-SZn-0.6Zr. By increasing Zn content and SiC addition, decomposition rate of three magnesium alloy is increased from 2.30 to 5.62, 7.24 mg· cm-2· h-1 , respectively. The compressive strength of the alloy is decreased linearly with the weight loss of the magnesium alloy during the degradation process, which is attributed to the anode dissolution of α-Mg matrix, the detachment of tiny particles and the no negative effect on degradation process of degradation products.