Mg量对过共晶Al-18%Si合金组织与性能的影响

Effect of Mg Content on Microstructure and Mechanical Properties of Hypereutectic Al-18% Si Alloy

为改善Al-18％Si组织形貌,利用扫描电镜与金相显微镜观察了不同含Mg量过共晶Al-Mg-18％Si合金的显微组织,并测试相应的力学性能,研究了强化处理的作用。结果表明:镁在过共晶Al-Si合金中的作用是通过热处理来实现,随镁含量的增加,合金的强度稍有增加,但伸长率有所下降。为了提高金相组织与力学性能,Mg量应控制在0．5％-3．0％。

With the view of improving morphology, SEM and optical microscope were used to observe the changes of the microstructure on hypereutectic Al-18% Si casting alloys with different content of Mg, and relative mechanical properties were tested. The effects of intensifying treatment had been investigation. Experimental results show that the effect of Mg in hypereutectic Al-Si casting alloys is come true by heat treatment. With Mg increasing in alloys, strength will increase, but elongation decline. To improve morphology and increase the mechanical properties of hypereutectic Al-18% Si alloys,the content of Mg should be limited within 0.5%～3.0%.