Casting core sands

Dehydrated Sodium Silicate Bound Core Sand for Aluminum Casting... 

A process has been developed at Ford Motor Company that uses dehydrated sodium silicate as a core binder for aluminum casting Silicate sand binders are attractive for their environmental qualitiesy such as the lack of organic emissions and odory and for other properties beneficial to the casting process O). 

The final step in a core process is the destruction of the core within a solidified casting and the removal of used core sand. The time necessary to remove used core sand is called the shake-out time. The technique used for de-coring aluminum castings is to hit them with an impact hammer (13) ... 

To investigate formulation and process variables, the amount of core sand shaken out of a casting is monitored as a function of impact hammer exposure. Fig. 12 shows shake-out data for one silicate solid concentration and one cast metal to core sand weight ratio. The most obvious effect is that the more angular lake sand shakes out of castings faster than round grain sand. This was found true for all silicate ratios and silicate binder contents investigated. Low ratio silicates,... 

Core sand can be removed from cooled castings in 0 1 to 0 2 minutes using impact hammer techniques ... 

Emission and consiunption levels for permanent moulding processes depend on the type of alloy used, the surface area of the melt, the quantity of the sand cores which are inserted in the mould, and the siuface/volume rate of die casting. The sand cores are the main sources of emissions. There is no important difference between the different casting techniques. Due to the wide variety of processes and applications, it is not possible to give average data. [202, TWG, 2002]... 

Metalodlew s.a. (2002). "A site for regenerating of self-hardening moulding core sands in the cast steel foundry Metalodlew s.a.", Metalodlew. 

Coordination number liquids, 6, 7 solids, 7 Cope, 135 Core sands, 139 Cores, 135, 151 Coring, 62, 63, 119 Cost of casting processes, 164 Critical nucleus, 16, 22 Critical radius, 16, 23 Crossjoint, 178 Crystal growth see Growth Crystallography of dendl-itcs, 65... 

Sandarac [9000-57-1] Sandblasting Sand casting Sand cores Sander Cramer test Sandimmun(e) Sand-lime brick Sand mills Sandofan... 

Foundry Resins. In the foundry industry, phenoHc resins are used as the binder for sand in the manufacture of sheU molds and cores. The two mating halves are joined by clamps or a bonding agent to form a sheU mold into which the molten metal is poured for castings. The sheU is formed by depositing a resin—sand mix on a hot metal pattern plate. After a certain period the pattern is inverted and the excess resin sand is removed. The sand particles are bonded by an oven cure, and the sheU is ejected from the pattern plate. 

Fillers are used in tooling and casting application. Not only do they reduce cost but in diluting the resin content they also reduce curing shrinkage, lower the coefficient of expansion, reduce exotherms and may increase thermal conductivity. Sand is frequently used in inner cores whereas metal powders and metal oxide fillers are used in surface layers. Wire wool and asbestos are sometimes used to improve impact strength. 

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