SINGLE CRYSTAL CONVERSION CONTROL

摘要

PURPOSE: An improved method for conversion of a single crystal to a polycrystalline article and controlling method thereof are provided which are useful for conversion of polycrystalline alumina to a solid state for providing single sapphire. CONSTITUTION: A method comprises the steps of providing a predetermined spatial temperature profile thereat having a maximum temperature approaching a melting temperature thereof by applying heat at a first end of the article; initiating conversion at the first end by maintaining the temperature profile; and correspondingly propagating the conversion along the article by moving the heat along the article toward an opposite second end.