Characteristics and history of molybdenum alloys
Molybdenum alloy, in 1910 began to use powder metallurgy process to produce molybdenum products. Until 1945 the powder metallurgy process was the only industrial process for the manufacture of sheet, wire and bar molybdenum. A non-ferrous alloy with molybdenum as matrix and other elements added. The main alloying elements are titanium, zirconium, hafnium, tungsten and rare earth elements.
Molybdenum alloy is a non-ferrous alloy composed of molybdenum matrix and other elements. The main alloying elements are titanium, zirconium, hafnium, tungsten and rare earth elements. Titanium, zirconium and hafnium can not only strengthen molybdenum alloy by solution, but also form stable and dispersive carbide phase, and improve alloy strength and recrystallization temperature. Molybdenum alloy has good thermal conductivity, electrical conductivity and low coefficient of expansion. It has high strength at high temperature (1100 ~ 1650℃) and is easier to process than tungsten. It can be used as gate and anode of electron tube, support material of electric light source, and used to make die casting and extrusion mold, spare parts of spacecraft, etc. Molybdenum alloy has low temperature brittleness and welding brittleness, and is easy to oxidize at high temperature, so its development is limited. Molybdenum alloy produced by industry has molybdenum titanium zirconium system, molybdenum tungsten system and molybdenum rare earth system alloy, more applications is the first kind. The main strengthening ways of molybdenum alloy are solution strengthening, precipitation strengthening and work hardening. Through plastic processing, molybdenum alloy sheet, molybdenum alloy strip, molybdenum alloy foil, molybdenum alloy pipe, molybdenum alloy bar, molybdenum alloy wire and profile can be produced, and its strength and low temperature plasticity can be improved.
An alloy based on molybdenum with other elements added. Among refractory metals, molybdenum and its alloys have good thermal and electrical conductivity and low coefficient of expansion (similar to the glass of electronic tube), high strength at high temperature (1100 ~ 1650℃), easy to process compared with tungsten, Therefore, it is used in electron tubes (gate and anode), electric light source (support material), metal processing tools (die casting and extrusion die and perforated tip) manufacturing sector and aerospace industry. Molybdenum resists etching by molten glass and its oxides do not contaminate the glass. Molybdenum has been used as a heating electrode in the glass industry since 1943. Mo-30w alloy has excellent corrosion resistance of molten zinc and has been successfully used in zinc smelting industry. Molybdenum is also used to make parts such as heat exchangers and valves in sulphuric acid production.
In 1910, molybdenum products were produced by powder metallurgy. Until 1945 the powder metallurgy process was the only industrial process for the manufacture of sheet, wire and bar molybdenum. In order to meet the needs of atomic energy, aviation and aerospace technology, Mo-0.5Ti-0.02C alloy and Mo-0.5Ti-0.1Zr-0.02C (TZM) alloy have been developed. From the late 1960s to the early 1970s, Mo-HF-C alloys with higher strength were made. China began to produce molybdenum products from powder metallurgy billets in the late 1950s. Later, two kinds of billets, powder metallurgy and smelting, are used to produce bars, wires, plates, foil, tubes and rectangular tubes for molybdenum and its alloys.
