Sand casting mold

Indirect materials are necessary to manufacture, test, and ship the product. Indirect materials are not part of the finished product. Sand used to build a sand-cast mold is an example of indirect material. There is a cost associated with indirect material, and in some situations the indirect material can be used over. 

Magnesium alloys are available in a variety of metal forms, including cast ingots, slabs, and billets sand, permanent-mold, die, and investment castings forgings extmded bars, rods, tubes, stmctural and special hoUow and soHd shapes and roUed sheet and plate. Magnesium alloys are used widely in a great variety of appHcations. 

S, sand cast P, permanent mold cast D, pressure die cast. Aluminum and impurities constitute remainder. Table 22. Mechanical Properties of Aluminum Foundry Alloys ... 

Property AHoy No. 8, Sand Cast Permanent-Mold Sand Cast Sand Cast, H.T. 

Sand Casting. Sand casting is the most popular method of molding for cast copper alloys. It is the least expensive near net shape process, and pattern costs are low. Dimensional tolerance capabiUties vary widely and are the least accurate when compared with other methods of casting. 

Aluminum bron2e alloys have been successfully cast ia the centrifugal, continuous, permanent, plaster, and sand molding methods. Depending on the alloy, the minimum tensile strengths of sand-cast test bars are 448—620 MPa (65,000—90,000 psi). 

Extracted from the American National Standard for Ductile-Iron Pipe, CentrifugaUy Cast in Metal Molds or Sand-Lined Molds, for Water or Other liquids, ANSI A21.51—1976, with permission of the piihlisher, the American Society of Mechanical Engineers, New York. 

S = sand-cast P = permanent-mold-cast other = temper designations. 

Foundries purchase new, virgin sand to make casting molds, and the sand is reused numerous times within the foundry. However, heat and mechanical abrasion eventually render the sand unsuitable for use in casting molds, and a portion of the sand is continuously removed and replaced with virgin sand. The removed sand becomes spent foundry sand, which is discarded from the foundry facility. 

In open-mold casting, the shape of the desired object is carved as a "negative" depression or hollow into a suitable bulk of material that withstands the temperature required for the process wood is often used for cold casting molds stone, sand, and dry mud, for hot casting. The fluid casting material is then poured into the carved depression, where it is left to set and from which, when solid, it is finally removed. 

Hollow sand casting is a relatively simple process for making cast metal objects that for thousands of years was the most widely used of all casting methods. For the most basic castings, the molds are made from ordinary silica sand mixed with water so as to keep the sand particles compacted together to maintain the required hollow-shaped form. The hot, fluid... 

The casting alloy products comprise sand castings, permanent mold castings, and die castings. Aluminum is the basic raw material for more than 20,000 businesses in the United States. Aluminum is an indispensable metal for aircraft, for example. See Fig. 3. Representative aluminum alloys for a broad classification of uses is given in Table 1. 

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