Piston plated by 0.5-3u tin on the surface in chemical way ,the tin layer with little hole has the lubri-cative quality of soft meta...

• 在活塞表面用化学方法镀覆05.；-3的锡层，多孔的锡层有软金属的良好润滑特性，能吸附较多润滑剂，降低了活塞与气缸音的摩擦功