Preparation of semi-solid A356 aluminum alloy slurry by TBR (Taper Barrel Rheomoulding) technology

Effects of pouring temperature, rotating velocity of inner barrel and shearing temperature on microstructure of semi-solid A356 aluminum alloy slurry which was prepared by self-developed TBR machine were investigated. The results indicate that it is favorable to obtain semi-solid aluminum alloy slurry structure with fine and spherical solid particles uniformly distributed in the eutectic matrix by reducing pouring temperature, increasing rotating speed of inner barrel or decreasing shearing temperature appropriately. The desirable microstructure of semi-solid A356 aluminum alloy with average primary solid phase diameter of 41 jim and shape factor of 0. 89 can be observed with pouring at 660°C and rotating inner barrel at 500 r/min as well as shearing at 590°C . The formation of the semisolid microstructure is controlled by the co-action effects of fragmentation and inhibited growth of dendrite.