Determination of Rigidity point/temperature using thermal analysis method and mechanical technique

•New approach defines rigidity temperature using cooling curve analysis.•It will be a novel application of thermal analysis in aluminum casting industry.•Dendrite coherency and rigidity temperature define the interdendritic feeding region.•New feeding parameters will be used as input data for simulation.•Dendrite coherency and rigidity temperatures give understanding of defects formation. The aim of this paper is to introduce a new method for determining Rigidity temperature applying cooling curve analysis. The determined values of Rigidity temperatures for three AlSi8Cu3 alloys with different contents of Strontium using thermal analysis technique have been compared with Rigidity temperatures obtained using mechanical technique (viscosity measurement). It was established that there is good correlation between measured values of Rigidity temperatures determined using both above mentioned techniques. Characteristic solidification temperatures such as liquidus, dendrite coherency point, Rigidity and solidus temperature have been recognized as important parameters of solidify aluminum alloys because they mark transitions between several types of feeding mechanisms. So far the Rigidity temperature can be only determined using mechanical technique. Potential application of Rigidity temperature as an input parameter for simulation software has been also discussed.