Influences of Master Alloys and Their Preparation Conditions on Microstructures of Semi-solid A356 Alloy Slurries

The influences of four treatment processes on the microstructures of semi-solid A356 alloy slurries are experimentally studied,respectively using A356 alloy powder,pure Al powder,Al-5Ti-B powder and Al-5Ti-B deformation alloy.The results show that with the multiple technology of melt treatment+reversible electromagnetic stirring and the addition of 0.15wt.% Al-5Ti-B alloy powder with average size of 100 μm,the semi-solid A356 slurry with shape factor of 0.8 or above and grain size of 80 μm(in air-cooling state) would be prepared in about 1 min;that the addition of 10%-15% pure Al powder with order of magnitude of micron would obtain the grain refinement effect equivalent to that of Al-5Ti-B deformation alloy;and that the mixed solid-liquid cast technology,using A356 alloy powder with average size of 100 μm,don't fit to serve the rapid preparation of semi-solid A356 alloy slurry.