... (lighter in weight and higher thermal conductivity); Senior Cast Iron (heavier in weight, greater strength and resistance to wear); ... Si Alloy, Eutectic Al-Si Alloy, Multi-Cast Iron and Ductile-Cast Iron etc.Piston ProcessCasting, Forging, Melted Metal Squeezing. ... Three or Four Ring Grooves, Ceramic Spraying and Hard Iron Plating etc.AdvantagesAnti-high Temperature,No Deformation,Hard-wearing and Easy ...