Tin plated, also called Sn plated, is the most economical surface treatment. Tin is an type of metal with silver color. It is non-toxic and soft. As we all know, in the piston motion, both the piston and cylinder will be worn. If they are made of same material, it will seizure. Additional, the replacement cost of cylinder is much more expensive than the piston. So we need to protect cylinder. The tin surface is soft and good ductility, it can protect the cylinder from being worn in the high strength motion and save replacement cost. Meanwhile, the tin is antioxidant and tarnish resistant, which can increase the service life of engine piston.
Tin Plated and Anodic Oxidation surface treatment
Manufactured from high quality aluminum alloy materials, the service life and durability of piston can be guaranteed. But the piston motion is an continuous and high-strength movement, suitable engine piston surface treatment can not only improve the abrasion resistance but also can reduce friction and improve operation efficiency.
Engine piston has various surface treatment to extend the service life and protect piston from frequent abrasion, friction and impact.
Tin plated surface treatment is antioxidant and tarnish resistant.
Piston with phosphating surface is in gray-black color. With the development of technology, we need improve the surface treatment to suit the high requirements of piston and internal combustion engine. When the metal meet dilute phosphoric acid or phosphate solution, it will form a phosphate film. The film can protect the piston body from corrosion and improve the adhesion performance. Additional, the phosphating surface treatment can be used for lubrication and attrition reduction.
Phosphating coating can improve the abrasion resistance of piston.
Anodic oxidation surface treatment is an expensive technology, which is commonly used in the piston head for friction resistance and crack resistance. Some high-power diesel engine, especially direct injection diesel engine set the combustion chamber in the piston head. In the high strength and high frequency piston motion, the piston head is easy to cause thermal fatigue and generate cracks. The essence of anodic oxidation is to transfer the aluminum alloy surface to a high density film named as Al2O3. The oxidation film has superb heat-insulating property, which can form a heat block to slow down the heat flow and improve the thermal fatigue resistance.
Anodic oxidation surface treatment in the piston head.
Graphite painting is an film, which is designed for lubrication, increasing service life and protecting engine. The graphite painting is commonly used in the piston skirt. With the development of engine piston, more fuels flow into cylinder, which make the viscosity of lubricating oil decreases and reduce the load capacity of engine. Graphite has outstanding lubrication performance, which can be used as lubricant even in the harsh conditions. Additional, the graphite painting can improve the wear resistance and noise reduction performance. Because the graphite surface has a type of special binder, it will not fall off or be worn off.
Graphite painting on the metal color aluminum piston skirt.