Introduction to Thermal Spray Coating

What is thermal spraying coating?

Thermal spraying is a new technology that using electric energy or fuel gas as heat energy to let the coating materials become molten state or semi-molten state, and using gas to atomized them into tiny liquid droplets or high temperature particles, then spray them onto cleaned and preprocessed mechanical parts’ surface with high speed and let the mechanical parts have special features. Thermal spraying technology is a new technology of material surface strengthening and protection. It has important status in surface modification technique field and always is national key popularized new technical project.

What are the types of thermal spraying?

According to different heat source, there are plasma spraying, HOVF, electric arc spraying, explosion spraying and laser spraying and so on. If according to coating material’s shape, there are powder spraying, wire spraying and ceramic rod material spraying and so on.

Thermal Spraying Method and Coating Material

• According to different mechanical parts’ different requirement on coating performance, we need to use different thermal spraying method and coating material. Thermal spraying technology can let all kinds of mechanical parts’ surface have a thin, compact and uniform special performance coating which has excellent performance of abrasive resistance, corrosion resistance, Insulation, radiation protection, high temperature resistance, oxidation resistance, heat insulation, electrical conductivity, anti-sticking and so on, thereby recover and prolong mechanical equipments ’ life-span with good economic benefit and social benefit, so thermal spraying technology has been widely used in aerospace, aviation, metallurgy, chemical industry, shipbuilding, machinery, coal, electric power, petroleum, textile and other industrial sectors. Several commonly used thermal spraying methods will be illustrated below.

Anti-Sticking Wear-Resistant Coating

Mainly used in coating machines, printing machines, printing and dyeing machines, tape production machinery, diaper production machinery and other transmission rollers. Usually, some drive rollers of these equipments need to contact the glued surface, printing surface or printing surface, and the undried printing surface and printing surface are easy to contaminate the roller and affect the surface pattern of the product.

Stripping strength of traditional anti-sticking coating “Teflon” is too strong for hot melt adhesive. That is the anti-sticking performance and wear-resistance is not too good which led anti-sticking performance will lose effect in a short time. It will lead to low production efficiency, short maintenance cycle and high cost.

The invention patent (patent number: ZL 2010 1 0543575.X) independently researched and developed by our company "thermal spray anti-stick wear-resistant coating" adopts plasma thermal spray technology, uses nickel-based alloy dispersion bond polymer anti-stick material, and uses bionics "Lotus leaf effect", the coating has extremely low adhesive peeling force and excellent wear resistance, and the overall performance is dozens of times higher than that of Teflon coating, reaching the national leading level in this field.

Conductive Eco-friendly Coating

The plasma sprayed conductive environmental protection coating uses a titanium oxide ceramic material called Magneli phase structure. This coating has unique physicochemical and electrochemical properties, especially excellent chemical stability and corrosion resistance, and at the same time has high conductivity of metal-like materials, and is currently the most chemically resistant conductive material.

Application：

1. Electrochemical oxidation technology is used to treat the protective coating on the surface of the electrode plate of industrial and domestic sewage environmental protection devices.

2. Lead-acid batteries and fuel cells and other new battery plate coating materials.

3. Electrode protective coating for equipment such as hydrometallurgy, electroplating, and precious metal recovery.

Coating material：

Titanium oxide?Ti4O7

Fiber Wear-Resistant Coating

Plasma sprayed ceramic materials are mainly used, mainly aluminum oxide titanium and chromium oxide series oxide ceramics. This kind of material has high hardness, corrosion resistance, and certain toughness. It has excellent and stable wear resistance and wear reduction performance under the condition of insufficient lubrication and heat dissipation. The coating structure is dense, and the surface can be polished to an "orange peel"-like surface morphology with controllable roughness, and has an appropriate friction coefficient, so that the spinning fiber can obtain moderate twist and tension. At the same time, the coating has semiconductor properties, which can eliminate static electricity caused by fiber friction.

Application：

Chemical fiber, cotton spinning, glass fiber and other textile machinery, chemical fiber twisting spindle cup, chemical fiber hot roller groove, short fiber double twister wear-resistant accessories, and wear-resistant coatings for various spinning machine accessories.

Coating material：

1. AT3 (Al2O3/TiO2 97%/3%): Grey coating, good corrosion resistance.

2. AT20 (Al2O3/TiO2 80/20): The coating is dense, with high hardness and good toughness.

3. AT40 (Al2O3/TiO2 60%/40%): dense coating, good toughness, high bonding strength.

4. Cr2O3: High hardness, low friction coefficient, good corrosion resistance, abrasive wear resistance.

Chuangzhi: supply and support of advanced, innovative surface coating technology

As a member of Thermal Spraying Specialized Committee of China Surface Engineering Association, Chuangzhi has been devoted to the R&D and promotion of thermal spraying technology and concentrated on the enterprise management for more than 15 years. Company owns a skilled, high efficiency and high-quality R&D and production team, and has acquired many proprietary technology and patent certification.

Chuangzhi has established a whole set of excellent and advanced thermal spraying technology through the introduction of domestic & foreign advanced equipments, such as plasma spraying equipment, HOVF equipment and electric arc spraying equipment, and varieties of finish machining techniques and testing methods. Chuangzhi has passed the quality management system certification ISO9001:2008. With excellent products and technical services, now our products are exported to Europe, the United States, Japan, Taiwan and many other countries and regions.