Experimental Study of Correlation of Mechanical Properties of Al-Si Casts Produced by Pressure Die Casting with Si/Fe/Mn Content and Their Mutual Mass Relations

The submitted contribution addresses problems concerning influence of alloying elements (Si/Fe/Mn) of Al-Si pressure die casts (HPDC) on values of residual deformation. On the basis of results of executed experiments, mutual correlations are analyzed and described, while not only measurements results are evaluated but also metallographic outputs of obtained compounds from the view of their formation, occurrence, and size. The development of intermetallic phases structures Al(FeMn)Si as well as intermetallic ferritic phase Al3FeSi was observed. More verification experiments follow in order to apply obtained knowledge for improvement and/or preservation of casts properties on required level. 1. Introduction Parts manufactured by pressure die casting distinguish by suitable properties in relation to their mass. In present, these products/casts are utilized in various spheres of industries, significant share of which is automotive industry [1]. An important requirement in this sphere is resultant mass of products, whilst all claimed properties are preserved. The trend of mass reduction leads to application of aluminium-based materials, while demands on strength, extensibility, and other mechanical properties are on the same level as for Fe-based materials. The paper describes basic impacts of chosen alloying elements on permanent deformation as a significant mechanical property. Mutual correlations between chosen alloying metals and resulting deformation measured on a group of casts are described. Consecutively these relations are observed during variation of content of the alloying elements in order to increase resulting strength of the cast. Providing stability in casting process is of great importance, since it has direct impact on resulting cast properties [2–4]. Aluminium alloys are die cast under pressure on casting machines with cold chamber [5, 6]. Significant factor of the process is corrosive effect of liquid aluminium alloys particularly at higher temperatures, this effect makes it impossible to employ casting machines with hot chamber [6–8]. Horizontal cold chambers are relatively simple, and it is possible to apply higher specific pressure on the cast metal. Thus, it is possible to cast light-walled casts with smooth surface and high mechanical properties. These advantages of horizontal chamber make it possible to design large casting machines with voluminous loading chamber and closing force up to 30？MN, with gross cast mass 30？kg or more, in casting of aluminium alloys (charge utilization of 80%) [6, 9, 10]. The quality of aluminium casts