Research Of Temperature Field And Thermal Stress Of SiC Mirror During High-temperature Vacuum Sintering

Carborundum is becoming the prime material of reflection mirror, as material science develops. The main equipment of SiC mirror preparation is vacuum high-temperature vacuum sintering furnace. The previous researches reveal that temperature distribution, heat transfer and temperature gradient changes within sintering furnace has important influence on Carborundum reflection mirror sintering process. The performance-price ratio of the experimental study on large-scale Carborundum reflection mirror sintering is rather low, because of long sintering period, costs and difficulty in detection of mirror billet temperature data. So, Numerical simulation is becoming a mainly method in the research of Lens mold agglutination.This article take silicon carbide reflector vacuum high temperature sintering furnace as the object of study, the paper analysed the actual hot working process characteristic of the furnace body idiographicly, has carried on the simplification to the structure which was lesser influenced in heat transfer analysis, constructs the reasonable physical model. Based on this, obtains from the heat transfer differential equation, as studies the tool auxiliary take ANSYS, establishes the three dimensional unsteady state value simulation model which in the sintering furnace transfers heat, using the hot transient state finite element method to carry on the value simulation to the vacuum high temperature sintering furnace’s temperature field, using radiation matrix unit to construct the vertical boiler internal radiation model, the lens mold temperature field conducts the numerical simulation research to the sintering furnace. Through enlarging the furnace body heat insulating layer size and the enhancement thermal rating analysis furnace binding and the hot craft to the lens mold temperature field influence.Through in thermal energy coupling unit computation burn and undercooling lens mold internal thermal stress distributed situation.The result indicated that the maximum temperature difference is6.09℃, it does not exceed10℃requirement; enlarging the heat insulating layer size to be possible to improve the lens mold average temperature, enlarging the thermal power will cause the lens mold temperature difference to elevate. In the foundation of obtaining the lens mold transient state temperature distribution, using the cylindrical work piece thermal load numerical calculus model, carries on the numerical simulation to lens mold’s transient state thermal stress, obtains the biggest thermal stress load to appear in the lens mold edges and corners place, the biggest thermal stress value is5.78MPa, in allowable stress scope. The furnace binding and the hot craft satisfy the silicon carbide reflector burn requestion, then getting the improvement through the numerical simulation method to the furnace binding and the hot craft, to instruct the practice production.