Correlations between Defect Content, Mechanical Properties and Fractographic Investigation of AlSi9Cu3(Fe) Alloy Reference Castings

Abstract

High Pressure Die Casting (HPDC) is a foundry process particularly suitable for high production rates and applied in several industrial fields, but the amount of scrap, caused by defects or incomplete filling, is sometimes very high. Thus it is important to know which are the main causes of defect formation and their effects on microstructure and mechanical properties. This paper presents, within the European MUSIC project, the qualitative and quantitative results of a study conducted on AlSi9Cu3(Fe) alloy castings, referred to as Horse-shoe Reference Castings, specifically designed to generate different kinds of defects with different severity levels. The work focuses on the correlations obtained between the casting mechanical properties, their defect content in terms of porosity and oxide films and the process parameters adopted, mainly second phase plunger velocity and intensification pressure. The three point bending test was carried out on the four specimens obtained from the two appendixes of the casting. The fracture surfaces were studied by scanning electron microscopy (SEM) and optical microscopy (OM) highlighting that the defect content is clearly correlated to the mechanical properties and the process parameter settings.

Functional and Environmental Advantage of Cleaning Ti5B1 Master Alloy

“…The presence of oxide films in master alloys causes various opinions among experts. While some view a reasonable amount of oxide films as excellent nucleation sites [28,29] the other reason that oxides have a little contribution in instigating crystallization but have a detrimental effect on mechanical properties in the final structure [30][31][32]. In current work, the commercial master alloy has an order of magnitude more oxide agglomerates than clean master alloy, but it didn't change liquidus, primary undercooling, or recalescence temperatures in a favorable direction.…”