The products of tungsten and molybdenum for sapphire long crystal furnace are mainly made of tungsten materials and molybdenum materials with purity higher than 99.95%, including tungsten crucible, tungsten plate, tungsten sheet, tungsten wire, tungsten electrode screen, tungsten cylinder and tungsten heat shield and molybdenum crucible, molybdenum heat shield, molybdenum heater, molybdenum heat field, molybdenum support frame and molybdenum electrode screen, etc. In addition to tungsten molybdenum products, tungsten rhenium wire is also a necessary product in sapphire furnace.
Sapphire furnace tungsten products are steel gray to tin white hard metal, very pure tungsten can be sawed (pure tungsten is very brittle, not easy to process). The processing methods of tungsten include forging, drawing and impact. The highest melting point of tungsten is 3415 ℃, the lowest vapor pressure and the highest tensile strength (1650 ℃). The corrosion resistance is very good, and most inorganic acids have little corrosion on it. A protective oxide is formed on its surface in the air, but it will completely oxidize at high temperature. Molybdenum products are also refractory metals with high temperature resistance and high melting point.
Sapphire growth furnace aims to cultivate sapphire single crystal by bubbling method. This method is to heat the raw material (alumina) in the tungsten crucible to its melting point 2050 or above, then gradually reduce the melting temperature, and make it crystallize into special particles. The furnace is constructed in a closed mold with a special insulated shell, cover and heater Therefore, tungsten and molybdenum products for sapphire long crystal furnace have emerged.
