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The mechanical properties of thixoextrusion components can be improved by controllable processing parameters such as the solid fraction of alloy, holding time, punch velocity, heat treatment and die temperature. In this study, the effects of thixoforming parameters on the microstructures and mechanical properties of thixoextrusion ADC12 alloy Aptomat Contact are studied. ADC12 has excellent castability with high fluidity and low shrinkage rate, so it is widely used in industry, especially in automotive and motorcycle engine part casting. It is a near eutectic alloy with high strength and low ductility (1%). The optimization parameters mechanical properties were investigated by changing the punch velocity, specimen temperature and holding time. The results also indicated optimal value at punch velocity (15 mm/s), specimen temperature (560 °C) and holding time (5 min) which was changed microstructure from eutectic dendrite to globular grain, increasing the ductility (3.3%) of this alloy during the semi-solid forming process while the remaining mechanical properties lead to an increase in the quality of finished parts.

The present work presents the results of experimental investigation of semi-solid preparation billet of ADC12 Al alloy using a cooling slope. The experiments have been carried out following central composite design. Three-key process variables at five different levels (pouring temperature, slope angle, and length of travel of the melt) have been considered for the present experimentation. Regression analysis and analysis of variance (ANOVA) have also been performed to develop a mathematical model for particle size of evolution of primary α-Al phase using response surface methodology. Finally, the best processing condition has been identified for optimum particle size (48.27) as slope angle of 65°, pouring temperature of 580 ℃, and 300 mm length of travel of the melt. The effect of pouring temperature, slope angle, and length of travel of the melt were identified to find the most important effects.