Thermal sprayingis a series of process,in the process, fine and dispersed metal or non metal coating material in a molten or semi molten state, deposition to a substrate surface after preparation, forming a spray deposition layer. The coating material can be powdered, banded, filamentous or rod-shaped heat. Spray gun from fuel gas, arc or plasma arc with the necessary heat, the thermal spraying material is heated to a plastic state or molten state, and then subjected to acceleration of compressed air, the constrained particle beam impact onto the substrate surface. The impact to the surface of the particles, and the deformation by stamping, forming a laminate sheet. The adhesion after substrate surface preparation, then cooled and piled up, eventually forming a layered coating. The coating for different coating materials can realize high-temperature corrosion resistance, abrasion resistance, heat insulation, anti electromagnetic wave function.

The correct choice of thermal spray coatingmaterial is the key to ensure the work required for the properties of the coating. The coating materials selection, should first consider the working conditions and performance of workpiece coating required, but also consider the workpiece material, batch, economy and intends to adopt the method of thermal spraying coating. According to the function of the coating can be divided as the corrosion resistant coating, abrasion resistant coatings, friction reducing and sealing coating,high temperature resistant thermal barrier coatings, insulation or conductive coating, the size of repair coating.

The surface of the workpiece after coating in the rejection caused by failure reason is often not a single factor, so can meet the requirements of working conditions and performance of the coating does not necessarily exist simple relationship should be analyzed in detail. According to the working conditions,and reference and experimental data on the coating structure, physical, chemical, mechanical and other comprehensive performance consider, in order to determine one or several kinds of coating materials.

Wear resistant coating is one of the main fields of the application of surface coating technology. Although there is a general relation between the hardness and wear resistance, hardness and wear resistance but not entirely representative of the surface coating. Because of the different types of wear properties of material is not the same, and in the wear and often accompanied by shock, corrosion influence of fatigue, and temperature.

The choice of surface coating materials can not blindly pursue high performance or high price of the coating material, resulting in unnecessary waste of material price can not be used as selection of thermal spray coating quality standards, in order to meet the working conditions of reaction requirements, as far as possible the use of cheap coating materials, is particularly important in mass production when for example, can use the material of Ni based alloy coating without cobalt base alloy coating materials.

Posted by: hannahgwendolyn at 09:15 AM | No Comments | Add Comment
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