Influence of Deformation on the Microstructure and Low-temperature Refining Behavior of Al-3.5P Master Alloy

In this paper, the influence of deformation on the microstructure and low-temperature refining behavior of Al-3.5P master alloy was investigated. The results show that the average size of AlP particles can be reduced obviously from 15.3 μm to about 2.1 μm by deformation. However, it exhibits entirely opposite influence on refining performance when Al-3.5P master alloy was deformed at room temperature and high temperature, respectively. Only when Al-3.5P master alloy was subjected to thermal deformation, can an improvement of low-temperature refining performance be obtained. In this condition, primary Si in A390 alloy can be refined from 137 to 21 μm, making it a potential candidate for die casting production. A mechanism associated with the transformation of particle-matrix interface during deformation has been proposed and further experiment has been designed to validate it.