Determination of pressure in the extradendritic liquid area during solidification

• Published in: Journal of thermal analysis and calorimetry 2018-06, Vol.132 (3), p.1661-1667
• Main Authors: Svidró, P., Diószegi, A., Jönsson, P. G., Stefanescu, D. M.
• Format: Article
• Language: English
• Subjects: Algorithms; Analytical Chemistry; Austenite; Casting defects; Castings; Chemistry; Chemistry and Materials Science; Clausius-Clapeyron equation; Computational fluid dynamics; Dendritic structure; Extradendritic liquid pressure; Fourier thermal analysis; Graphite; Inorganic Chemistry; Lamellar graphite iron; Latent heat; Liquid flow; Mathematical analysis; Measurement Science and Instrumentation; Physical Chemistry; Polymer Sciences; Solidification; Volume change measurement
• ISSN: 1388-6150; 1588-2926; 1588-2926
• DOI: 10.1007/s10973-018-7088-z

Complex-shaped lamellar graphite iron castings are susceptible to casting defects related to the volume change during solidification. The formations of these recurring defects are caused by the flow of the liquid in the intradendritic area, between the austenite dendrite arms, and in the extradendritic area between the austenite grains. The conditions for the liquid flow, in turn, are determined by the solidification behavior. The present study suggests a new measurement method and a novel calculation algorithm to determine the pressure of the extradendritic liquid during solidification. The method involves a spherical sample suspended in a measurement device, where the temperature and the volume changes are measured during solidification. The calculation algorithm is based on the numerical interpretation of the Clausius–Clapeyron equation where the temperature variation, the volume change and the released latent heat are processed to determine the local pressure of the extradendritic liquid area during solidification.