Casting costs

Daniels, J.A. and J.A. Doulhett "New Alloys Cut Auto-Casting Costs." Advanced Materialr A Prates so. 211 tFebruary 990i. 

The efficiency of gas turbines is limited by the maximum allowable turbine inlet temperature (TIT). The TIT may be increased by cooling of the blades and vanes of the high pressure turbine. Cooling channels can be casted into the components or may be drilled afterwards. Non-conventional processes like EDM, ECD or Laser are used for drilling. Radiographic examination of the drilled components is part of the inspection procedure. Traditional X-Ray film technique has been used. The consumable costs, the waste disposal and the limited capacity of the two film units lead to the decision to investigate the alternative of Real-Time X-Ray. 

Solution Casting. The production of unsupported film and sheet by solution casting has generally passed from favor and is used only for special polymers not amenable to melt processes. The use of solvents was generally very hazardous because of their flammabiUty or toxic nature. The cost of recovery and disposal of solvents became prohibitive for many lower price film appHcations. The nature of the drying operations leads to problems with solvent migration and retention that are not problems with melt-processed polymers. 

The resin, catalyst, and microhalloons are mixed to form a mortar which is then cast into the desirable shape and cured. Very specialized electrical and mechanical properties may be obtained by this method but at higher cost. This method of producing cellular polymers is quite appHcable to small quantity, specialized appHcations because it requires very tittle special equipment. 

Poly(vinyl chloride). To be converted into film, poly(viayl chloride) [9002-86-22] (PVC) must be modified with heat stabilizers and plasticizers, which increase costs. Plasticized PVC film is highly transparent and soft, with a very high gas-permeation rate. Water-vapor transmission rate is relatively low. At present, PVC film is produced by blown-film extmsion, although casting and calendering are employed for heavier gauges (see Vinyl POLYAffiRS). 

The automotive industry is the principal user of P/M forgings, primarily for transmission and differential components, but also for engine parts. Other markets are in power tools and farm machinery. Cost effectiveness is generally the reason for substituting P/M forgings for conventionally forged, cast, or machined parts. 

Synthetic Marble. Synthetic marble-like resin products are prepared by casting or molding a highly filled monomer mixture or monomer—polymer symp. When only one smooth surface is required, a continuous casting process using only one endless stainless steel belt can be used (52,53). Typically on the order of 60 wt % inorganic filler is used. The inorganic fillers, such as aluminum hydroxide, calcium carbonate, etc, are selected on the basis of cost, and such properties as the translucence, chemical and water resistance, and ease of subsequent fabrication (54,55). 

Iron is the preferred metal for casting steel and nonferrous metals are used in smaller amounts. Most castings are made in green sand molds, ie, uncured molds of sand, clay, and water. However, the use of sheU mol dings is growing, because such mol dings permit reproducibUity of castings with close dimensional accuracy. In addition, the simplicity of equipment procedures reduces costs. 

Total hip implants of the nature described have hospital Hst prices ia the range of 5000— 8000. Fully custom-made implants cost approximately 10,000. The low end basic total hip implant is forged or cast stainless steel, cemented ia place, one size fits all, and costs 1000. 

A wide range of cutting-tool materials is available. Properties, performance capabilities, and cost vary widely (2,7). Various steels (see Steel) cast cobalt alloys (see Cobalt and cobalt alloys) cemented, cast, and coated carbides (qv) ceramics (qv), sintered polycrystalline cubic boron nitride (cBN) (see Boron compounds) and sintered polycrystalline diamond tbin diamond coatings on cemented carbides and ceramics and single-crystal natural diamond (see Carbon) are all used as tool materials. Most tool materials used in the 1990s were developed during the twentieth century. The tool materials of the 1990s... 

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