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AssigneeGM Global Technology Operations LLC
InventorsJongcheol Shin, Jongwon B Park, Inwook Hwang, Bob R. Powell, Jr., Thomas A. Perry, Anil K. Sachdev, Jon T. Carter
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Some die cast aluminum alloy articles have internal cylindrical surfaces such as the round internal cylinder surfaces of a cylinder block for an internal combustion engine. During casting solidification molten aluminum alloys shrink against the metallic permanent mold tools used to mold and define such internal surfaces, and tend to stick to the tool surfaces making it difficult to remove the casting. The tendency of some aluminum casting alloys to solder to the tool can further intensify sticking. In this invention, an aluminum alloy sleeve is placed on and over the tool surface before casting and the sleeve isolates the tool from the molten aluminum. The sleeve becomes bonded to the casting and facilitates removal of the casting from the tool. The sleeve may be (and preferably is) fully machined from the internal casting surface. The sleeve may be of the same composition as the casting, in which case handling and recycling of machining chips would be facilitated. The practice of the invention is also applicable to die casting of magnesium alloys using magnesium sacrificial sleeves.
A method of die casting an aluminum alloy article of predetermined composition and having an internal cylindrical wall surface, the cylindrical wall surface having at least one predetermined internal cross-section dimension and a height, the method comprising:
A method of die casting an aluminum alloy article or magnesium alloy article of predetermined composition and having an internal round cylinder wall surface, the round cylinder surface having a predetermined internal diameter and height, the method comprising:
Dependencies are inferred from the claim text.