A356铸造铝合金中孔洞缺陷对应力应变集中程度的影响

Effect of Porosity Defects on Stress Concentration in A356 Aluminum Casting

针对铸造过程中出现缩孔、气孔等缺陷,导致大载荷条件下应力集中,产生局部高应力应变区引起局部屈服,从而降低零件服役寿命的问题,采用有限元简化建模和试验分析验证相结合的办法,系统地研究了A356铸造铝合金中孔洞与自由表面距离、孔间距、孔形貌,以及孔角度对应力应变集中程度的影响,建立了孔洞各缺陷特征对应力应变集中影响的关系,并通过试样内实际孔洞对所建立的关系进行了验证。

In response to the occurrence of defects such as shrinkage and porosity during the casting process,which lead to stress concentration under high load conditions,produce local high stress-strain zones and local yielding,resulting in reducing the service life of the parts.By using a combination of finite element simplified modeling and experimental analysis verification,the effects of the distance between micropores and the free surface,the distance between the pores,the porosity morphology and the distribution angles on the stress concentration in A356 cast aluminum alloys are systematically studied.The relationship between the influence of each defect feature on the stress-strain concentration is established,and the established relationship is verified by actual pores in the sample.