| 摘要 |
A die casting method using vacuum and partial squeeze is provided to improve compactness of a product texture by providing optimal conditions in a step of performing a processes of vacuum die casting and squeeze casting of a die cast article with a 30 to 50 mm thick-walled part. A die casting method using vacuum and partial squeeze comprises: a first step of pouring a melt of an Al-Si alloy with a temperature of 665Œ20 deg.C into an injection port of an injection sleeve(13); a second step of pushing the melt at a transfer speed of 0.25 to 0.5 m/s by an injection plunger(20); a third step of creating a vacuum or 20 mm Hg or less in a casting-forming part(11) of a mold(10) within 0.6 to 1 second right after the injection plunger passes through the injection port of the injection sleeve; a fourth step of pushing the melt at a transfer rate of 2 to 3 m/s by the injection plunger to inject the melt into the casting-forming part; and a fifth step of pressurizing a thick-walled part(11a) of the melt into the casting-forming part at a pressure of 3010 to 3020 kgf/cm^2 for 1 to 1.5 second by a squeeze cylinder(30) with the passage of a predetermined time after completing supply of the melt into the casting-forming part, wherein the thick-walled part has a thickness of 30 to 50 mm.
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