PURPOSE: To improve durability by forming a piston with high-temperature magnesium alloy, by providing its skirt with a chemically applied or electrodeposited metallic sliding layer which has given thickness and hardness, and by coating the inside surface of the piston with a plastic cracker.
CONSTITUTION: A piston 1 is formed with pressure-diecast of magnesium alloy belonging to a material group Mg5Nd, a skirt reinforced by 20 vol.% of aluminum oxide fiber is coated with a chemically applied nickel layer (sliding layer) 3 which has a thickness of about 10-30 μm (preferably 16-24 μm) and a hardness of about 740-850 HV0.01. The inside surface of the piston 1 is coated with a layer 2 formed with a plastic cracker having a thickness of 15 μm. Particles of chromium oxide or similar ceramic oxide material is buried in the sliding layer 3, and the magnesium alloy 2 contains 2-6% of neodymium.
BORUFUGANGU HENINGU
FURANTSU BAISU
KAARU GEERUDAA
NISSAN MOTOR
ATSUGI UNISIA CORP