汽车用铝合金在搅拌摩擦加工下的组织改性与力学性能分析

Microstructure modification and mechanical properties analysis of aluminum alloy for automobile with friction stir processing

探讨了搅拌摩擦加工对汽车用YL112铝合金显微组织和力学性能的影响。结果显示,经搅拌摩擦加工后, YL112铝合金的孔隙率明显降低, α-Al内部的树枝状结构遭受严重破坏, YL112铝合金中较大的第二相粒子和针状Si相得到有效分解。分解后的产物在搅拌摩擦加工的熔核区域均匀重分布,进而使YL112铝合金的微观结构得到细化。此外,搅拌摩擦加工显著提升了YL112铝合金的抗拉强度及断后伸长率。在低延展性及高孔隙率存在的区域, YL112铝合金容易发生断裂,而经过搅拌摩擦加工处理, YL112铝合金的微观组织被重组改善,最终展现出更优异的综合力学性能。

The effects of friction stirring processing(FSP)on the microstructure and mechanical properties of YL112 aluminum alloy for automotive were investigated.The results show that the porosity of YL112 aluminum alloy is significantly reduced after friction stirring processing,the dendritic structure insideα-Al is severely damaged,and the larger second phase particles and the needle-like Si phase in YL112 aluminum alloy are decomposed effectively.The decomposed products are uniformly redistributed in the melting core region of friction stirred processing,which refines the microstructure of YL112 aluminum alloy.In addition,the friction stir processing significantly increases the tensile strength and elongation after fracture of YL112 aluminum alloy.In the region with low ductility and high porosity,YL112 aluminum alloy is susceptible to fracture,and the microstructure of the YL112 aluminum alloy is restructuring after friction stir processing,the YL112 aluminum alloy shows superior comprehensive mechanical properties.