摘要：The microstructure and mechanical properties of a gravity die and sand cast Al-10%Si-0.4%Mg alloy, which is one of the most important and frequently used industrial casting alloys, were examined. Tensile test samples were prepared from fan blades and sectioned through three positions which experienced different cooling rates. Furthermore, the inherent strength potential of the alloy was revealed by producing homogeneous and well fed specimens with a variety of microstructural coarseness, low content of oxide films and micro-porosity defects, solidified in a laboratory environment by gradient solidification technology. The solidification behaviour of the alloy was characterized by thermal analysis. By means of cooling curves, the solidification time and evolution of the microstructure was recorded. The relation between the microstructure and the mechanical properties was also assessed by using quality index-strength charts developed for the alloy. This study shows that the microstructural features, especially the ironrich needles denoted as ?-Al5FeSi, and mechanical properties are markedly affected by the different processing routes. The solidification rate exerts a significant effect on the coarseness of the microstructure and the intermetallic compounds that evolve during solidification, and this directly influences the tensile properties.
