Plansee uses the creep-resistant tungsten material WVM to manufacture heaters for sapphire growth. These have more than twice the service life of conventional tungsten heaters. Sapphire growth takes place at high temperatures of approximately 2100 °C. In the Kyropoulos process, rod heaters made from pure tungsten are generally used. These often have to be replaced after just a few cycles. This is due to the high level of embrittlement and deformation. It can sometimes be so extreme that the heater rods touch the shielding and cause short-circuits. To meet the needs of ...