The invention provides a
thermal analysis and detection method and device for solidification grain size of a
magnesium alloy melt and belongs to the fields of
magnesium alloy melt treatment and
casting solidification. The
thermal analysis and detection method provided by the invention comprises that certain amounts of
magnesium and
magnesium alloy melt are poured into a sampling cup to be cooled, two thermocouples are adopted for respectively determining temperatures at the center and the edge of the melt in a solidification process in a
magnesium alloy melt cooling process, a temperature acquisition device is used for acquiring temperature data, a
computer program is used for recording variation of the temperatures at the center and the edge of the melt in the solidification process along with time, then dendritic
crystal coherence point
solid phase fractional number is determined by virtue of a
thermal analysis and detection method, and the dendritic
crystal coherence point
solid phase fractional number is compared with a standard value to judge a refining or roughening effect on the grain size of a
magnesium alloy by modification, grain refining or alloying element addition. According to the thermal analysis and detection method and device provided by the invention, recalescence is not required in a thermal analysis
cooling curve of the solidification process, the thermal analysis and detection method and device provided by the invention are especially applicable to the magnesium
alloy with lower solidification
latent heat release, a modification effect can be represented within a wider solidification speed range, and solidification grain size can be predicted.