Calculation of cooling rate of amorphous aluminum alloy melt-spun ribbons
(1.中南大学粉末冶金国家重点实验室，长沙4100832.湖南省长沙市中南工业大学粉末冶金国家重点实验室3.湖南省长沙市中南大学粉末治金国家重点实验室)
Abstract: Based on the heat transfer theory and liquid solidification theory, the heat transfer during the rapid solidification process of amorphous ribbons prepared by melt spinning was approximately modeled by one-dimensional heat conduction equation. Besides, integration with the temperature gradient, the relationship between the ribbon thickness and solidification time was derived according to the boundary conditions of ribbon-copper wheel. A simply theoretical model was obtained to calculate the cooling rates of aluminum amorphous ribbons. According to the above theoretical model, the critical cooling rate of aluminum amorphous ribbons by melt spinning is above 106 K/s, which proves that the aluminum based alloys belong to the marginal glass forming ability of alloys. The calculated results are in good agreement with other estimated values reported previously.
Key words: aluminum amorphous ribbon; rapid solidification; cooling rate; melt spinning; heat transfer