Assessment of Grain Size and Grain Refinement Efficiency by Calculation of Released Heat Attributed to Formation of Primary Aluminum Crystals During Solidification of Al7Si4Cu Alloy

Assessing heat released only related to the formation of primary crystals provides results with a significantly higher sensitivity than a traditional assessment of undercooling value. In this work, two similar Ti5B1 master alloys (commercial and refined) are used for grain refinement of Al7Si4Cu aluminum alloy to assess narrow differences in heat release during primary crystallization. The heat released related to primary crystallization is 2.50 ± 0.03, 3.16 ± 0.12, and 7.92 kJ kg−1 for samples treated with the refined master alloys, commercial master alloys, and sample solidified without grain refinement, respectively. The acquired results showed that the suggested method is more efficient in comparison with traditional metallographic or undercooling methods for the assessment of grain refining efficiency with the potential to extend the suggested approach on a wide range of metallic structures where solidification occurs by eutectic-type primary crystallization characteristics.