| 摘要 |
PURPOSE:To improve the strength and toughness of an Al casting by the synergistic effect of the dispersion strengthening of specific fine particles for strengthening and the precipitate formed by a heat treatment by dispersing said particles in molten Al and casting the molten Al. CONSTITUTION:Fine particles for strengthening such as SiC or others of <=10mu are added and dispersed in molten Al or Al alloy at <=20% volume ratio at intervals within 10mu. Such molten metal 12 is admitted through a charging port 10 into a plunger sleeve 4, and a counter chip 8 is gradually lowered to introduce the molten metal through a gate 9 into a casting cavity 3 for product formed of upper and lower dies 1, 2 to 1/4-1/3 of the space is said cavity. A pressurizing plunger 5 is thereafter screwed down to force the molten metal in the sleeve 4 into the cavity 3 and to solidify the molten metal. After the molten metal is held for 8hrs at 515 deg.C, the metal is hardened in water and is then tempered at 170 deg.C. The disperison strengthened Al alloy which is uniformly dispersed with the fine particles for strengthening, is dispersed with the fine particles in dendrite as well and has excellent strength with the precipitation of the resulting product of the heat treatment is obtd.
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