Molybdenum is a refractory metal, melting point is 2630℃, recrystallization temperature is about 900℃, high strength at high temperature, good processing performance, both heat resistant coating material, but also heat resistant hydrochloric acid metal material. Molybdenum has low friction coefficient and good wear resistance.
When spraying molybdenum, the molten molybdenum on the surface can be dissolved into the metal matrix, and even metallurgical bonding can be formed on the surface of the cut smooth workpiece. The thickness of the bonding layer is about 1 cm, so it is also commonly used as the bottom material. Molybdenum and a lot of metals such as ordinary carbon steel, stainless steel, cast iron, aluminum and its alloy matrix form a good combination, so molybdenum coating is often used as the machine bed guide coating bottom.
In addition, some MoS2 impurities will remain in the molybdenum coating, or react with sulfur to produce MoS2 solid lubrication film, so the molybdenum coating can be used as wear resistant coating, such as piston ring, brake pads, aluminum alloy cylinder and other friction surface working coating.
Molybdenum spraying, the use of flame wire spraying, this is because of the low cost of the process, simple operation, easy to achieve automation. Plasma spraying molybdenum powder has the advantages of dense coating and low oxide content, and molybdenum powder can be mixed with other powder materials, which creates favorable conditions for plasma spraying molybdenum powder.
The main disadvantage of molybdenum is easy oxidation, its oxide (MoO3) melting point (about 780 degrees) is low, and volatile, therefore, higher than the melting point will be rapidly consumed by oxidation.
