| 摘要 |
PURPOSE:To prevent a piston from damage due to fusion or out of lubrication without causing increase in its weight by making the top land and head, at the piston basis consisting of a light metal, from a composite material with good heat resistance and small coefficient of thermal expansion. CONSTITUTION:Fibers 5 with lower coefficient of thermal expansion and higher heat resistance than light alloy such as aluminum alloy or magnesium alloy to constitute the piston basis 1 are embedded in the top land 4 and head part 2 of the basis 1 to form a layer 6 of composite material composed of fibers and light alloy. As fiber material is selected among such long filaments as alumina, silundum and carbon, such short fibers as alumina, alumina-silica and carbon and such whiskers as silundum, silicon nitride and potassium titanate. |
