| 摘要 |
<p>The piston is cast in a die cavity which is shaped in conformity to the desired exterior surface of the piston. An annular ring (30) of wear resistant austenitic iron material is disposed in the die cavity. A predetermined amount of molten aluminium alloy is poured into the die cavity over the ring, and the die cavity is closed by a punch (70) which applies a force to the aluminium alloy as it solidifies. The pouring is facilitated by a pouring disc (50) placed in the top of the die cavity to distribute the molten alloy, via apertures (54) arranged around its periphery, over the insert ring (30); the disc (50) also includes a vent (58). Prior to its placement in the mould, the ring (30) is dipped in molten aluminium to pre-heat and coat it. <IMAGE></p> |
