| 摘要 |
Shaped metal articles are produced on a continuous basis from semisolid metal preforms. The metal preforms are sequentially heated, then transferred, without substantial deformation or heat loss to a press where they are shaped in the semisolid state into shaped articles. While in the press, a ram is employed to drive the preform into a cavity of adjacent tooling to thereby shape the article. Prior to the forming operation, the ram is first advanced until it lightly engages the preform, then is withdrawn by a spaced distance to a first position defining the beginning of a stroke. Then, the ram is advanced, rapidly, from the first position against the preform to a second position contiguous with the tooling, thereby defining the end of the stroke. The spaced distance is chosen so as to preclude substantial heat drain from the preform and/or forced entry of air into the cavity and/or splashing of the semisolid metal outside of the cavity. Just before reaching the second position, the ram may be accelerated to preclude the formation of voids in the finished article.
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