Tungsten Strengthening Alloy
Tungsten alloy includes solid solution strengthening alloy, dispersion strengthening alloy, precipitation strengthening alloy, compositing strengthening alloy, and tungsten composited alloy containing copper, silver, or cemented carbide.
Solid solution strengthening alloy includes lanthanated tungsten, tungsten molybdenum, and tungsten tantalum alloy. Lanthanated tungsten is one of the representative solid solution strengthening alloys. It has a high melting point, strength, hardness, ductility, recrystallization temperature, and electrical resistance. It also has low vapor pressure, low electron work, and ductile to brittle transition temperature.
Dispersion strengthening tungsten alloy can be grouped into two types. One is oxidized dispersion strengthening alloy composed of tungsten and oxidized rare earth metals. The other is cemented dispersion strengthening alloy composed of Si, Al, and K elements in tungsten. Rhenium composed tungsten has a higher DBTT than pure tungsten and also a stronger tensile strengthening than tungsten under 1500oC. K metal composed tungsten processes an excellent sagging resistance and a higher DBTT than pure tungsten. Besides, K metal improves the tungsten alloy’s ductility under its recrystallizing status.
High density tungsten alloys are tungsten alloys with nickel and iron or nickel and copper additions. Cemented tungsten alloys include tungsten carbides containing 3%-25% zirconium as the only rest composite and tungsten carbides containing titanium and zirconium with specific compositing ratios.
Molybdenum Strengthening Alloy
Molybdenum’s alloying process theoretically employs the same strengthening methods as the tungsten alloying process, including solid solution strengthening, dispersion strengthening, precipitation strengthening, and compositing strengthening.
Rhenium can increase the strength of molybdenum both at room and high temperatures. It also raises the recrystallization temperature and ductility of molybdenum. K metal boosts the high-temperature strength and ductility of molybdenum wire and rod materials.
Molybdenum copper perfectly combined both the molybdenum and copper’s favored properties with a wide range of compositing ratios. Copper and molybdenum both have high thermal and electrical conductivity. Copper has a high thermal expansion rate, low hardness, and low melting point. In contrast, molybdenum has a low thermal expansion rate, high hardness, and high melting point while keeping excellent conduction. By adjusting the composing percentage ratio of molybdenum and copper, molybdenum copper can achieve an expected thermal expansion rate and ductility for a specific application while keeping the thermal and electrical conductivity high. When the working temperature of molybdenum copper reaches above the melting point of copper, liquidized copper can bring the inner heat out while evaporating to cool down the molybdenum copper.