Optimization of processing parameters of cooling slope process for semi-solid casting of ADC 12 Al alloy

In the present work, the effect of processing parameters of cooling slope techniques (pouring temperature, slope angle and slope length) of ADC 12 Al alloy on its microstructural evolution has been studied in detail. A series of cooling slope casting experiments were conducted by varying the pouring temperature (580, 585 and 590 °C), slope length (400, 500 and 600 mm) and slope angle (30°, 45° and 60°). The effect of processing parameters on the response factors, viz. degree of sphericity and particle size, has been investigated by applying analysis of variance (ANOVA), interaction graphs obtained using response surface methodology. The obtained results infer that optimum values of the degree of sphericity (0.865) and particle size (49.30) are observed for the following set of processing parameters, namely 585 °C pouring temperature, 500 mm slope length and 45° slope angle. ANOVA results show that the pouring temperature is the most significant input variables that influence degree of sphericity and particle size followed by slope length and slope angle. The values of output variables obtained from confirmation experiment, performed at 95% confidence level, ensure that they are well within the permissible limits