Experimental Investigation Of Rheological Gravity Forming By LSPSF Method

Semi-solid slurry of A356 aluminum alloy with bulk volume, semi-solid hub and stock of 6063 aluminum alloy were produced by Low Superheat Pouring with a Shear Field (LSPSF) technology, which was self-designed and built. The effects of different parameters on slurry and casting's macro-micro quality were analysed, those mechanical properties were tested, and corrective measures for different defects were proposed. The main research results are as follows:Semi-solid slurry of A356 aluminum alloy with bulk volume was prepared successfully by LSPSF process. The evolvtion regular of pouring weight, rotating speed of the duct, tempreture, cooling rate, and holding time on primary phase microsturcture were studied. The results showed that the semi-solid slurry quality was high and steady, the mean equivalent diameter and shape factor of the primary phase was 37.8μm and 0.85. Otherwise, the requirement of prepare semi-solid slurry on production line rapidly was satisfied. The microsturcture of cooling time in 60 seconds showed that the slurry's quality was fine, and mean equivalent diameter and shape factor of primary phase was 32.1μm and 0.85.Semi-solid hub of A356 and stock of 6063 aluminum alloy were prepared by LSPSF technology. Those quality and property were analyzed from exterior, internal structure and machanical property. The experiments and results showed that the hub's surface glazing, obviours defects were not found, internal cut neat, and gas porosities were discovered. The crystal grain of semi-solid slurry and hub was small and uniformity, its shape rounding. The semi-solid hub's tensile strength was 150MPa, yield stress was 85MPa, elongation strain was 2.0%. Semi-solid stock'surface has not obvious defects, its quality was high. The stock of 110mm and 130mm diameter's mean equivalent diameter was 67.5μm and 75.9μm respectively, its shape factor was 0.80 and 0.83. Tensile strength of the stock was 147.42MPa and 153.96MPa separately. Contrast with traditional process, LSPSF could increase production efficiency, accelerate crystal grain tessellate and shape rounding, the effect of mechanical propertiy has not found. LSPSF technology's process is simple, efficient, and its semi-solid slurry's quality good, it has great prospect.