Research on fractal characteristics of primary phase morphology in semi-solid A356 alloy

Zheng LIU 1,2),Xiaomei LIU 1),Chunhui HU 2) and Weimin MAO 3) 1) Faculty of Mechanical and Electronic Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China 2) Jiangxi Nonferrous Metal Processing Engineering Research Center,Ganzhou 341000,China 3) School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China

摘 要：Semi-solid slurry of A356 alloy was prepared by low superheat pouring and slightly electromagnetic stirring,and the fractal characteristics of morphology in semi-solid primary phase was researched.The fractal dimensions of primary phase morphology in the semi-solid A356 alloy were calculated by the program written to calculate the fractal dimensions of box-counting in the image of solid phase morphology in semi-solid metal slurry.The results indicated that the morphology of primary phase in semi-solid A356 prepared by low superheat pouring and slightly electromagnetic stirring is characterized by fractal dimension,and the primary phase morphology obtained by the different processing parameters has different fractal dimensions.The morphology of primary phase at the different position of ingot has different fractal dimensions,which reflected the effect of solidified conditions at different positions in the same ingot on the morphology of semi-solid primary phase.Solidification of semi-solid alloy is a course of change in fractal dimension.

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