Under what circumstances can I use spraying coating process

       

Spraying coating process should be adopted
in the following cases:

1) The hardness of the coating is HV130-350,
the thickness of the coating is from 0.3 to several millimeters, and the
surface roughness is Ra10-25 μ m. The surface roughness of the coating after
grinding can reach Ra0.8-0.4 μ m. Such as the bearing parts of various shafts.

2) It is required to be resistant to
cavitation and water erosion, and the roughness after machining shall not
exceed Ra0.4 μ M surface, such as imported automobile crankshaft, train
crankshaft, marine crankshaft, etc.

3) The material is copper alloy, aluminum
or aluminum alloy and other non-ferrous metals, which need to restore the size
or improve the surface wear resistance.

4) Copper based powder or aluminum powder
is the best choice for spraying on non-ferrous metal workpieces such as copper
alloy, aluminum or aluminum alloy.

5) When used in corrosive medium, the
coating is required to be dense without pores. According to the working
environment, working temperature, medium concentration and composition of the
workpiece, the plastic, ceramic or corrosion-resistant metal that can meet the
service conditions shall be selected. After spraying, the coating shall be
sealed with appropriate sealing agent.

6) Bonding strength of spraying layer and
substrate: the tensile bonding strength of traditional flame spraying layer is
generally 20-30N / mm2. ZK8032 powder multi-function high-speed flame spraying
gun newly developed and produced by Shaanxi Zhongke Surface Engineering Co.,
Ltd. is used to spray aluminum clad nickel composite coating on the surface of
nodular cast iron after sand blasting, and the shear bonding strength of the
coating can reach 63.7N/mm2; Although the bonding strength of the spray coating
is not as high as that of the spray welding coating, it is enough to meet the
needs of repairing the parts with lubricating metal friction and failure
resistance; For Dongfanghong 75 tractor, it is only 5.5N/mm2, which is far
lower than the shear strength of the coating.

7) Wear resistance of spray coating: take
the spray coating of automobile crankshaft as an example, the sprayed main
journal has higher wear resistance than the new crankshaft. Our company once
sprayed the Hino automobile crankshaft made in Japan, and the wear amount of
the repaired main journal is 0.022-0.03mm after overhaul, while the wear amount
of the main journal without spray coating is 0.2-0.25mm, which is almost ten
times different, From this example, it can be shown that the spray coating has
good wear resistance, even in the case of engine oil shortage, it can still
keep running for several hours without burning the Bush and holding the shaft.

If you want to know more about spraying
coat powder or spray welding powder,

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