1, thermal spraying
Thermal spraying is the use of certain source coating material is heated to a molten or semi-molten state, at the same time, with the help of flame and high speed gas which is atomized, and the atomized particle jet to the substrate surface, depositing a coating having a certain function. Thermal spraying for the workpiece surface with wear and corrosion resistance, high temperature resistant coating. Coating material and the substrate typically exists between three kinds of combination of mechanical, physical: binding and metallurgical bonding. With the low pressure plasma spraying, high energy, high speed plasma spraying, flame spraying technology, coating performance can be further improved the porosity can be decreased to 15% ～1%:; bonding strength between coating and substrate can reach 70～ 140MPa.
Research shows that, by using supersonic flame spraying ( HVOF ) and plasma spraying ( ASP ) technology, respectively, in 0Cr13Ni5Mo stainless steel substrate preparation of Fe-based amorphous alloy coating and iron base amorphous and nanocrystalline coatings, studied two coating at room temperature on the friction and wear characteristics, the results show that two kinds of spraying process for the preparation of iron base the coating has high hardness and low porosity, tight organization, is a typical layered structure, improve the coating wear resistance.
In order to make up for the stainless steel soft abrasion, friction coefficient of weakness, conventional electroplating method improve the stainless steel transmission shaft with pieces of the surface hardness and self lubrication performance. Stainless steel is a kind of surface passivation of metal, in must be removed before plating passivation film on the surface of stainless steel, deoiling, impregnation, activation, electroless nickel plating and electroplating process can be obtained, zinc, chromium, copper, tin, and other precious metals plating.
Research shows that, in the stainless steel turbine parent material, with periodic reverse plating rare earth chrome, plating thickness of about 013mm, coated by metal matrix phase and the second phase particles of rare earth salt composition, hardness can reach 900～ 1000Hv, coatings of abrasion resistance as parent material of 25 ~ 28 times, the product service life than the original pieces of stainless steel tall 2 ～6 times.