WSEAS Transactions on Heat and Mass Transfer
Print ISSN: 1790-5044, E-ISSN: 2224-3461
Volume 14, 2019
Unsteady numerical analysis of heat transfer and phase change during crystal growth process
Authors: , , , ,
Abstract: Controlling the melt-crystal (m-c) interface during Kyropoulos crystal growth and understanding the origin of re-melting phenomenon are challenging tasks for sapphire crystal growers. In this paper, a transient model is used to investigate the evolution of the melt-crystal interface in Kyropoulos crystal growth of sapphire. Internal radiation in semi-transparent sapphire is modelled with the discrete ordinates model (DO) and the phase change with the enthalpy method. During crystallization, the maximum convexity of the m-c interface coincides with the development of an angle on the m-c interface near the free surface leading to the appearance of re-melting zone that affects the sapphire single crystal quality and reduces significantly the ingot diameter. This simulation also shows that the m-c interface shape and the crystal length obtained at different growth stages agree well with the experimentally grown crystals including re-melting zones phenomenon.
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Keywords: heat transfer, crystal growth, Sapphire, unsteady simulation, re-melting phenomenon, mc interface.
Pages: 77-84
WSEAS Transactions on Heat and Mass Transfer, ISSN / E-ISSN: 1790-5044 / 2224-3461, Volume 14, 2019, Art. #9