汽车发动机缸体用Al-Si-X合金的复合铸造工艺研究

Research on Composite Casting Technology of Al-Si-X Alloy for Automobile Engine Cylinder Body

在熔炼过程中采用不同振动频率的机械振动辅助搅拌复合铸造工艺进行了汽车发动机缸体用Al-7Si-0.4Mg、Al-7.5Si-4Cu合金的制备,并进行了显微组织、力学性能和耐腐蚀性能的测试与分析。结果表明,随着机械振动频率从20 Hz增大到75 Hz,汽车发动机缸体用Al-7Si-0.4Mg、Al-7.5Si-4Cu合金的平均晶粒尺寸先减小后增大、室温抗拉强度先增大后减小、腐蚀电位先正移后负移;机械振动频率优选为50 Hz。

The Al-7Si-0.4Mg and Al-7.5Si-4Cu alloys for automobile engine cylinder body were prepared by using different frequencies mechanical vibration assisted mixing during smelting process. The microstructure, mechanical properties and resistance corrosion testing and analysis were carried out. The results show that with the increase of the mechanical vibration frequencies from 20 Hz to 75 Hz, the average grain sizes of Al-7Si-0.4Mg and Al-7.5Si-4Cu alloy for automotive engine cylinder body first decrease and then increase; the tensile strength at room temperature first increases and then decreases; the corrosion potential occurs the first positive shift and then negative shift; the mechanical vibration frequency of selective preference is 50 Hz.