alfin,oil cooling gallery & head anodized piston

This design is used for highly loaded diesel engines .For additional protection and in order to avoid cracking in the combustion chambar and the crown. the piston has a special hard anodized layer on the piston crown (head anodized )

Alfin piston  

Pistons having a reinforcing member in the top piston ring groove position are well known. Such members are used to reduce mutual wear between the piston ring groove and the co-operating piston ring. This is designed for the first piston ring groove of the inner combustible engine. Because of the high similarity of the thermal expansion indexes of High Nickel Austenitic Cast lron and aluminum-silicon alloy, the use of this type of material will prevent the loose and/or detachment of the carrier from the aluminum piston body due to the fluctuation of thermal and mechanicalloads.

GRAPHITE COATING

To improve wearing state and reduce gap between cylinder and piston Graphite has very high melting point. Under vacuum con-dition, until 3000℃ can it soften to melting, and at 3600℃ it starts to vaporize and sublime. Most materials' intensity well gradually become weaker under high temperature, but graphite's intensity will double when heated to 2000℃. But graphite has bad oxidation resistance. With the increase of temperature, its oxidation speed will also increase.

ANODIC OXIDATION

Anodic oxidation can effectively improve surface hardeness

CAST IRON

The piston is unique for a heavy-duty, high-speed diesel, as it is made of thin wall ductile castiron of 70 kg/sq mm tensile strength. Due to high material strength, coupled with an extremely rigid structure formed by a closed cooling gallery, the piston can withstand very high thermal and mechanical loads.

TIN COATING

Piston plated by tin on the surface in chemical way, the tin layer with little hole has the lubri-cative quality of soft metal. it can absorb more lubricative oil to drop the friction between the piston and cylinder.