亚洲AV中文字幕无码久久,国产精品日韩欧美一区二区三区,欧美性色欧美a在线在线播放,国产AV无码专区毛片|天天天天天天天天爽|亚洲成人网钻|亚洲一区二区在线播放懂色AV

Vacuum Furnace Molybdenum Heat Shield and hearing Belts

Refractory metals have a high melting point, low vapor pressure, low coefficient of thermal expansion, excellent high temperature strength and creep resistance. Through alloying, their processing properties and high temperature performances are further improved, and the service life of products is extended. Therefore, tungsten, molybdenum, tantalum and niobium metals are widely used in all kinds of high temperature furnaces as structural materials, heating body and insulation layer.