This article unmasks the probabilistic nature of high-pressure die casting; specifically, the cause of scatter in the tensile ductility of die-cast Al8Si0·4Mn0·3Mg (wt.%) alloy. Scatter in tensile ductility is related to the size of large pores and non-metallic inclusions. We propose that these non-metallic inclusions form during the pyrolysis of commercial plunger lubricants, and that these large pores derive from dilatational strains introduced during semi-solid deformation. The apparent randomness of pore formation is thus ascribed to the heterogeneous nature of the semi-solid network. Reducing heat loss in the shot chamber is shown to promote a more homogeneous grain structure, leading to a decrease in the maximum pore size from 1.32 mm to 0.37 mm, and an increase in the minimum tensile ductility from 6.8% to 9.4%.

本文揭示了高压压铸的概率性质。具体地说，是压铸Al8Si0·4Mn0·3Mg（wt。％）合金的拉伸延展性发散的原因。拉伸延展性的分散与大孔和非金属夹杂物的大小有关。我们建议这些非金属夹杂物在商业柱塞润滑剂的热解过程中形成，并且这些大孔源自半固态变形过程中引入的膨胀应变。因此，孔形成的明显随机性归因于半固体网络的异质性。降低喷丸室中的热损失可促进晶粒结构更加均匀，从而将最大孔径从1.32毫米减小到0.37毫米，并将最小拉伸延展性从6.8％增加到9.4％。