How to choose vacuum insulation screen material?

When selecting vacuum insulation screen material, its high temperature performance should be considered. The vacuum furnace can work stably for a long time under high temperature, and the deformation is small. Fast degassing, small volume of air in vacuum, heat shock, no pollution of products and furnace. Small blackness, high surface finish. The vacuum furnace heat shield should have high fire resistance, heat insulation, heat shock resistance and corrosion resistance.

Metal insulation screen: vacuum furnace metal insulation screen is mainly made of tungsten, molybdenum, tantalum and stainless steel.
The number of layers of heat shield is determined by furnace temperature, vacuum furnace power and vacuum furnace structure.
Theoretically speaking, the more layers the thermal insulation screen, the greater the thermal resistance, the smaller the heat loss.
However, having too many insulation screens has its drawbacks:
1. The insulation screen is too long, and the consumption of materials is too much;
2. The furnace structure is complex, which is unfavorable for installation and fixation;
3. The vacuum furnace inner surface suction volume increases, the gas is not easy to release, especially in the hot and humid summer, the vacuum degree is not easy to meet the requirements;
4. After the insulation screen exceeds 5-6 layers, the insulation effect of each layer gradually decreases.

The number of layers of the heat insulation screen should also consider the vacuum furnace capacity (power), if the furnace capacity is large, high furnace temperature, the number of layers of the heat insulation screen can be appropriately increased. Generally, 6-12 layers can be selected between 1700℃ and 2300℃.