Fabrication and properties of in situ (Al 3Zr + Al 2O 3) p/A356 composites cast by permanent mould and squeeze casting

Abstract

The A356 alloy and Zr(CO 3) 2 components are used to fabricate the in situ Al 3Zr, Al 2O 3 particles reinforced A356 aluminum alloy matrix composites by direct melt reaction method. The average particle sizes are in the range of 1–2 μm. The composite melt is cast by permanent mould (composite A) and squeeze casting (composite B). In composite B the conventional casting defects are less and the grains are finer than those in composites A. The casting process has little apparent effect on the granularity of particles. The tensile strength and elongation of composite B is 345 MPa and 15.07%, respectively, which are enhanced by 1.6 and 2.15 times than those of composite A. The abradability and corrosion resistance are also improved obviously. The better properties including tensile, abradability and corrosion resistance of composite B are attributed to the high density and finer grain of matrix via squeeze casting.