Study of Susceptibility to Tearing of AlSi5Cu2Mg Alloy with Addition of Zr and Ti

Abstract

The current trend of continuous improvement of various components constantly pushes the development of new materials forward. The basic goal of research into new and better materials is to improve their properties compared to the original material. One of the essential properties of the newly developed aluminum alloys is their resistance to the formation of tearing. Tears appear during the solidification of the casting and break the integrity due to tension arising while cooling. Several factors influence the susceptibility to tearing, but they can be minimized and reduce the chance of their occurrence. As part of the experiment, the AlSi5Cu2Mg alloy was evaluated in four material variants, without additives (in the reference state), with the addition of transition elements Zr, Ti and their combination Zr + Ti. Susceptibility to the formation of teras was assessed using a qualitative method supplemented by microscopic analysis of the tear profile and determination of the dendritic coherence temperature. The evaluation shows that the addition of Zr increased the susceptibility to tear formation. On the contrary, the addition of Ti had a positive effect and reduced the susceptibility to the formation of tears. The effect of the addition of Zr and Ti in the AlSi5Cu2Mg alloy showed a similar values as without the addition of alloys (reference condition). Microstructural analysis of the tear profile pointed to the negative influence of phases rich in Zr. The subsequent evaluation of the dendritic coherence temperature of individual AlSi5Cu2Mg alloys did not show a correlation with the results of a quantitative evaluation of susceptibility to tears.