摘要 |
A casting is formed by inserting a metal reinforcement coil into a mold cavity and injecting a plastic casting material into the cavity such that the coil becomes embedded within the plastic casting material. Prior to being placed in the cavity, the coil is heat treated to relieve stresses therein, and a layer of plastic is sintered to the outer surface of the coil. Plastic is injected into the mold at a temperature lower than the heat-treating temperature, but hot enough to melt an outer portion of the layer and become joined therewith. An inner portion of the layer remains sintered to the coil. <IMAGE> |