| 摘要 |
<p>A fiber reinforced porous preform (58) is positioned within a die cavity (55) defined by upper and lower die members (48,52), and the lower die member defines a gate opening (62) in the center portion of a water cooled shot sleeve (18) which receives a vertically moveable shot piston (18). The area of the gate opening is small relative to the area of the shot sleeve, and the lower die member defines an annular recess (65) above the inner surface of the shot sleeve for entrapping a shell of pre-solidified metal. Air vent slots (68) extend outwardly between the shot sleeve and lower die member and are closed by the shell of pre-solidified metal. The structure prevents pre-solidified metal and air from entering the die cavity.</p> |
