Study of Thermal Analysis for Monitoring of Liquid Metal in Production of Aluminum Casting

Abstract

The main objective of this study is to present the elementary path to develop applications of thermal analysis technique from the solidification in casting of hypoeutectic aluminum-silicon alloy. In order to successfully use the technique as a monitoring tool for an appropriate production of aluminum casting, all affecting process conditions must be taking into accounts when cooling curves are used as indicators. Although, the cooling curves can indicate the solidification characteristics, previous studies on casting trials designed by Taguchi method show that thermal analysis can be complex and sensitive. Also, there are many factors that influence the characteristics of cooling curves when grain refinement becomes more prominent. This study is to determine the effects of grain refiners and magnesium contents on the undercooling of nucleation of Alpha (α) aluminum phase. Different cooling rates and different magnesium contents were studied and the undercooling temperatures were measured. The cast samples were then subjected to the metallurgical analysis by macrostructure study to determine the average grain size. Under a controlled casting condition, it was found that grain refinement tended to decrease degrees of undercooling temperature. Also, higher magnesium content led to the suppression of the undercooling temperature.