Quantification of microstructure to reveal the solidification path of an alloy

Abstract

This paper reports on the development of Solidification Continuous Cooling Transformation diagrams that relate the solidification paths to the inherent microstructures of binary and ternary alloys. The methodology is based on the quantification of a solidified microstructure for its various phase fractions. This measured data is combined with well-established solidification models and phase diagrams to yield undercooling temperatures of individual phases. The thermal history and undercooling of different phases in the solidified alloy are estimated for a wide range of cooling rates (from 10-2 °Cs-1 to 105 °Cs-1). To describe the methodology, dedicated samples of Al-Cu, Al-Cu-Sc and Al-Si alloys were studied. With said alloys being solidified in a controlled manner, over a wide range of cooling rates and undercoolings, via Impulse Atomization, Electro-Magnetic Levitation, and Differential Scanning Calorimetry