SAPPHIRE IS HIGHLY ROBUST AT EXTREME TEMPERATURES:
A supported sapphire window can be taken to 1950℃ with no change to
its shape and minimal reduction to mechanical performance. Sapphire
windows are the perfect material for high temperature combustion
chambers, gas processing and lamp shields.
Sapphire flats are ideal for furniture, boats and standoffs in high
temperature furnace systems. Sapphire flats remain flat and
dimensionally "perfect" up to 1700℃. Because of sapphire's extreme
chemical resistance many materials will not stick to sapphire in
spite of high temperatures.
Sapphire windows and flats maintain the highest temperature rating
of all optical materials in both oxidizing and inert atmospheres.
Sapphire windows can withstand considerably higher temperatures
than the closest runner up material, fused silica, with zero
degradation. Fused silica will degrade and devitrify over time at
temperatures almost half the maximum operating temperature of
sapphire
