Composite materials have good mechanical properties such as high strength, high hardness and high wear resistance. They are widely used in the fields of automobiles, civil engineering and many other machine industries. Hopefully it will be used more wide engineering fields such as ship industry and slurry sucking up pumps, in which high resistance for slurry-erosion should be required. And also mechanical properties of the materials are known to depend on the microstructure. In this paper, relationships among microstructure, mechanical properties and slurry-erosion behavior are discussed on the specimens of pure Al, dispersion hardend Al alloys ( Al-Si alloys ), solution hardend alloys ( Al-Mg alloy, Al-Cu alloy ) and SiC particles inserted Al alloys for developing a material for slurry sucking up pump. Based on the experimental results, it was revealed that slurry-erosion resistance of the SiC particles inserted Al alloy shows about seven times higher than that of the dispersion hardend alloys and the solution hardend alloys. It was concluded that the SiC particles inserted Al alloys are a promising materials for the slurry sucking up pump
