Relative to other materials, tungsten & molybdenum used as heat shield have the

characteristics of low vitalization in high temperature,less pollution to crystal, furnace clean,

long service life, not easy to deformation and so on, so it is widely applied in sapphire thermal field.

REFRA will take in design concept of high temperature furnace and apply this concept in sapphire

thermal field. Heat shield has advantages of free expansion in high temperature, strong

resistance to deformation, so relatively with long service life.

http://www.c-rmm.org