Research Of Controllable Thermal Field Of 60kg-Grade Kyropoulos-method Sapphire Furnace

Sapphire has various excellent properties,and thus make it a good performance in the civilian,military,aerospace and other fields.Recently as the trend of LED sapphire made for substrate material rise quickly,as well as sapphire widely used for advanced electronic products' screen such as watches and phones,Sapphire Growth industry developed rapidly,People's demand for high-quality large-size sapphire has a large increase.However Sapphire Growth technology was coming from abroad and domestic-Sapphire Growth technology of large-size are far from perfect,in terms of K yropoulos method,the complexity of the process required make it also very complex doing the research of equipment used.Domestic experts and scholars have been engaged in research in this area,and numerical simulation of structure modification of the equipment were conducted,through computer simulation study.In this paper,for the purpose of exploring thermal field controllability of sapphire furnace of Kyropoulos method,research work we did as follows:Analysis of the componets of 60kg-grade K yropoulos-method sapphire device has been done,as well as various stages of the process.Get known that the seeding stage and constant-diameter stage are essential for the method,and then these two stages were focused on research.Based on the sapphire growth theory and sapphire 's thermal properties,the driving force for crystallization,homogeneous nucleation as well as the principle of non-homogeneous nucleation,the nucleation rate,cold hot ingredients were discussed and illustrated,concluded that in order to avoid crystallization process heterogeneous nucleation and constitutional supercooling phenomenon adversely affect the quality of sapphire,the control of the temperature gradient of the solid-liquid interface and the crystal growth rate is very important.In addition to the energy transfer equation of Kyropoulos-method sapphire growth device and various boundary conditions were theoretical elaboration,we decided to adopt DO radiation model,melting solidification models in ANSYS / FLUENT to solve the problem.60kg-grade sapphire furnace of K yropoulos-method 3D modeling,and the corresponding 2D model to ANSYS / FLUENT for simulation,seeding stage and constant-diameter stage's approximately thermal field structure were obtained.Thermal field structure convection causes,how it affects the temperature gradient of the crystal growth and adjust the direction of suitability were carried out a detailed analysis,combined with references were discussed.Causes of convection in the thermal filed,and how it affects the temperature gradient of the crystal growth were analyzed,and adjust the direction of suitability and carried out a detailed analysis,combined with references referred.Concluded that Thermal field control of seeding stage is difficult due to the high precision demand of the seeding temperature however the device cannot provide reliable temperature feedback value.Guidance phenomenon on Artificial seeding process such as "crescent shaped ring" "wavy lines" are difficult for machine recognition as judgment conditions,to design automatic seeding program must design new detecting device which can be used for machine recognition provides sensitive and reliable seeding state.Furthermore,good control of thermal field by adaptive fuzzy controller design to achieve.