The improvement of microstructures and mechanical properties of near eutectic Al–Si multicomponent alloy by an Al–8Zr–2P master alloy

In this article, the improvement of microstructures and mechanical properties of near eutectic Al–Si multicomponent alloys modified by an Al–8Zr–2P master alloy was analyzed. The phosphides exist in the form of granular ZrP particles with an average size of 30.0 μm in Al–8Zr–2P master alloy. By using this modifier, the average size of primary Si can be remarkably decreased from 78.6 μm to 11.6 μm under the optimal conditions determined by an orthogonal test. Besides the solid solution strengthening effect, it is investigated that the Zr element induced by Al–8Zr–2P master alloy has an improvement on the distribution and morphology of intermetallic phases. Therefore, the σb,20°C and σb,350°C (ultimate tensile strength) of the Al–Si multicomponent alloy modified by Al–8Zr–2P master alloy can be increased by 10.1% and 4.4% respectively, compared with that modified by Al–3.5P master alloy.