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Auto Alfin Steel 4D31 Mitsubishi Pistons Custom Made , ME012145 3300CC
Piston Technology
Graphite Sprayed at Piston Skirt/Graphite Printing
Graphite is characterized as good lubricating, which helps lubricant adhering to coating surface. The coating will reduce friction and scratching. The thickness is between 0.01 and 0.02 mm.
Tin Coating
Tin is coated by electro analysis or heat dipping at thickness between 0.001 and 0.003mm. Tin is characterized as soft and oil-friendly which improves running-in efficiency of piston and liner. This coating is most commonly used.
Piston roof anodizing
The piston roof is anodized by electro bath, forming thin layer of Al2O3 , This treatment will improve heat resistance (above 500), heat conductivity and anti-corrosion, it helps prevent piston roof burn-up. The thickness is normally 0.02 to 0.05mm. If the thickness increases by 0.01mm, the heat conductivity will decrease by 25%, the roof temperature when running will be lower from 30 to 50. Anodizing technology and processing is normally complicated.
Piston roof MoS2 Spraying
The function is close to roof anodizing improving heat resistance. The MoS2 is also good at lubrication. (The bigger piston below is piston roof anodizing, the smaller one is MoS2 Spraying)
Phosphate
The phosphate is aimed to improve initial running-in performance. The phosphate layer is easy to wear off and helpful to improve running-in.
Ceramic Spraying
The treatment performance is similar to anodizing and heat insulation performance is better. The ideal thickness is 0.2 to 0.3mm. When running under high temperature, the ceramic is easy to crack and wear off. It is not commonly used due to high cost
Piston Type
Steel-insert piston
Steel-insert piston allows more uniform thermal expansion and tight fitting clearance.
