Characterization of the effect of Sr and Ti on liquid quality in Al8Si3Cu

Abstract

Al8Si3Cu alloy was studied to investigate the effect of casting conditions on melt quality of the molten metal. While Sr and Ti master alloys were used as additional parameters, holding time was performed for effect of held liquid. Experimental study was tried before and after degassing. The reduced pressure test machine was used to produce samples which are five samples for each parameter. Samples were prepared by metallographic methods to be analyzed with via digital image processing. Pores on the surface of the samples were measured in number density and distribution of them was examined statistically. Results showed that while Sr addition and holding time increased casting defects by increasing porosity, degassing decreased the number density of defects, as expected. Therefore, it is a vital result that degassing process must be applied to every casting. In addition, Ti addition was found to have a slight positive effect to reduce porosity, but it was almost negligible when compared to that of degassing process. © The Minerals, Metals & Materials Society 2019.