Microstructure Transition of Liquid Metal Al During Heating and Cooling Processes

A simulation study of the transition properties of microstructures of liquid metal Al during heating and cooling processes has been performed by the molecular dynamics method. It is demonstrated that in the temperature range of 1800--350K, the 1551, 1541, 1431, 1311, 1321, and 1422 bond types represented by the Honeycutt-Andersen index play an important role. Especially, the 1551 bond type plays a leading role and is the decisive factor for the change of the second peak of the pair distribution function from a smooth sine peak into two split secondary peaks via a platform during all the processes of microstructure transitions. From the variation curve of the
1551 bond type, it can be clearly seen that there are five rapidly changing ranges corresponding qualitatively to the critical transition points of microstructures of the system detected experimentally.