Journal or Book Title
Metallurgical and Materials Transactions A
The influence of melt pool behavior on the competition between the nucleation of crystalline solidification products and glass formation is examined for an Fe-Si-B alloy. High-speed imaging of the melt pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt spinning (MS) rates for which fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt pool oscillation may be the dominant factor governing the onset of unsteady thermal conditions accompanied by varying amounts of crystalline nucleation observed near the lower limit. At high rates, the influence of these oscillations is minimal due to very short melt pool residence times. However, microstructural evidence suggests that the entrapment of gas pockets at the wheel-metal interface may play a critical role in establishing the upper rate limit. An observed transition in wheel-side surface character with an increasing MS rate supports this contention.
Copyright 2004 ASM International. This paper was published in Metallurgical and Materials Transactions A, Vol. 35, Issue 5, pp. 1539-1553 and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.
Napolitano, Ralph E. and Meco, H., "The role of melt pool behavior in free-jet melt spinning" (2004). Materials Science and Engineering Publications. 163.