Effects of wavelike sloping plate rheocasting and spheroidisation on microstructures and properties of Al-18%Si-5%Fe alloy

A novel method of preparing hypereutectic Al-Si-Fe alloy was proposed by wavelike sloping plate(WSP) rheocasting device,and the rheocasting and spheroidisation treatment of Al-18%Si-5%Fe alloy were investigated.The results reveal that the morphologies of primary crystal Si,Al18Si10Fe5 and Al8Si2Fe phase in this alloy can be improved obviously by WSP rheocasting.With the decrease of pouring temperature,various phases tend to be refined and spheroidised.The formation of microstructures in this alloy originates from three mechanisms such as crystal nucleus multiplication brought by crystallization rain,crystal restraining growth under strong cooling of sloping plate and crystal break-up under flow shear.The WSP rheocasting and spheroidisation treatment further improve the microstructure of Al-18%Si-5%Fe alloy.The Vickers hardness of the alloy is 87.5.The wear rate of Al-18%Si-5%Fe alloy under dry friction is 5.4 mg/h.