thermal spraying method and coating technology

1.Coating capabilities

When one engineering problem is raised, the first should be clear is to accept the construction of the part of the work-piece by spraying (usually work surfaces of equipment or facilities) in what kind of working conditions, and the function of coating is to identify the main features spraying process and materials basis, while also considering whether to allow the economy.

1.1 Coating diversity

Due to the diversity of spraying coating material of a variety of choice, the process parameters controlled variable and spraying methods. Spraying powder material over then one hundred species, wire and rods are also with dozens, different variations spraying methods and process parameters, enabling the formation of the same material different coating. So, the combination of these variables can get a " menu" type of coating series, when you need to have some kind of coating properties, just take from that is OK.

1.2 Coating category

Spray coating material（such as chronium carbide powder)sprayed can be divided 10 series according to their composition

(1) iron, nickel and cobalt-based coatings

(2) self-fluxing alloy coating

(3) non-ferrous metal coatings

(4) oxide ceramic coating

(5) tungsten carbide coating

(6) chromium carbide and other carbides coating

(7) refractory metal coating

(8) oxide ceramic coating

(9) plastic-based coatings

(10) cermet coating.

1.3 Coating function

On the basis of U.S. FN LONGO classification method of thermal spray coating, the coating can be classified by function:

1) Wearresistant coating. Including antiadhesive wear and surface fatigue wearresistant coatings and coating erosion. Some of the situation with difference of resistance to low temperature (< 538C) wear resistance and high temperature resistance (538 ~ 843C) wear coating.

2) thermal oxidation resistant coating.This kind of coating including high temperature process (which has an oxidizing atmosphere, corrosive gases, erosion and thermal barrier than 843 ℃) and the molten metal process (including the molten zinc, molten aluminum, molten iron and steel, the molten copper) of the applied coating.

3) anticorrosion coating and impregnation atmosphere. Atmospheric corrosion, including corrosion caused by industrial atmosphere, salt atmosphere, atmosphere and other fields immersion corrosion, including fresh drinking water, non-potable fresh water, hot fresh water, salt water, chemical and food processing, etc., causing corrosion

4) the conductance and resistance coating. This kind of coating for conductivity, resistance, and shielding.

5) restore the size coating. This kind of coating for ironbased (can be cut with a grinding of steel and corrosion resistant steel) and nonferrous metals (nickel, cobalt, copper, aluminum, titanium and their alloys) products.

6) mechanical parts clearance control coating. This kind of coating can be grinding.

7) chemical resistant coating. Chemical corrosion including corrosion of acid, alkali, salt, various inorganic and various organic chemical media.