932 Cast Products

The first aluminum products, including the first commercial application (a tea kettle), were castings, made by pouring molten aluminum into a mold. They are useful for making complex shapes and are produced by a number of methods [26]. Common methods and their ASTM specifications are:

B26 Sand Castings B85 Die Castings B108 Permanent Mold Castings B618 Investment Castings

Castings are made in foundries. Usually the aluminum to be cast is received in ingot form, but foundries located next to a smelter may receive molten aluminum directly from the reduction plant, and some foundries use recycled material. Castings make up about one half the aluminum used in automotive applications.

The minimum mechanical properties of separately cast test bars of cast alloys are given in Table 9.16. The average tensile ultimate strength and tensile yield strength of specimens cut from castings need only be 75% of the minimum strengths given in Table 9.16, and 25% of the minimum elongation values given in Table 9.16. The values for specimens cut from castings should be used in design because they are more representative of the actual strength of the casting.

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