Cast cement

Brick, concrete blocks, or pre-cast cement aggregate panels have been commonly used in the past. These materials tend to be labor intensive to install and are less economical than other methods. 

Figure 15.1. Supercritical fluid carbonation of cast cement. (Top) Idealized chemical reactions occurring during the manufacture of a cast Portland cement. (Bottom) Idealized chemical reactions occurring during the accelerated carbonation using supercritical C02.

Figure 11.13, (a) Comparison between strength and reliability of cast cement and plastic mixed cement, (b) Cement spring made by extruding plastic cement mix and winding It round a tube. 

Large quantities of zinc are used to produce die castings, which are used extensively by the automotive, electrical, and hardware industries. An alloy called Prestal(R), consisting of 78 percent zinc and 22 percent aluminum, is reported to be almost as strong as steel and as easy to mold as plastic. The alloy said to be so moldable that it can be molded into form using inexpensive ceramics or cement die casts. 

The industrial value of furfuryl alcohol is a consequence of its low viscosity, high reactivity, and the outstanding chemical, mechanical, and thermal properties of its polymers, corrosion resistance, nonburning, low smoke emission, and exceUent char formation. The reactivity profile of furfuryl alcohol and resins is such that final curing can take place at ambient temperature with strong acids or at elevated temperature with latent acids. Major markets for furfuryl alcohol resins include the production of cores and molds for casting metals, corrosion-resistant fiber-reinforced plastics (FRPs), binders for refractories and corrosion-resistant cements and mortars. 

Castings Investment Casting Institute 8521 Clover Meadow Dallas, Tex. 75243 American Die Casting Institute 2340 Des Plaines Ave. Des Plaines, lU. 60018 American Poundrymen s Society Gulf and Wolf Roads Des Plaines, lU. 60016 Steel Pounders Society of America 455 State Street Des Plaines, lU. 60016 Cement and Concrete Cement Statistical and Technical Association Mahno Sweden American Concrete Institute P.O. Box 19150 Detroit, Mich. 48219... 

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. 

Cast and Hand-Molded Refractories. Large shapes such as burner blocks and flux blocks, and intricate shapes such as glass feeder parts saggers are produced by casting sHps, hydraulic cement bonded mixtures, or hand-molding clay or chemically bonded materials. Because these techniques are labor intensive, they are reserved for articles that caimot be satisfactorily formed in any other way, owing to complexity or small production quantities. 

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... 

Parameter Carbon and low—medium aHoy steels High speed steels Cast cobalt alloys Carbides Cemented Coated Ceramics Polycrystalline cBN Diamond... 

Cast-Cobalt Alloys. Cast-cobalt alloys were introduced about the same time as HSS for cutting tool appHcations. Popularly known as StelHte tools, these materials are Co-rich Cr—W—C cast alloys having properties and appHcations in the intermediate range between HSS and cemented carbides. 

Most cemented-carbide tools are WC-based and have Co as the binder. Other carbide tool materials based on TiC having a Ni—Mo binder were developed primarily for high (>300 500 m/min) speed finish machining of steels and gray cast irons for automotive appHcations. 

Fig. 2. Tool wear mechanisms, (a) Crater wear on a cemented carbide tool produced during machining plain carbon steel, (b) Abrasive wear on the flank face of a cemented carbide tool produced during machining gray cast iron, (c) Built-up edge produced during low speed machining of a nickel-based alloy.

Refractories and Molds. Citric acid is used as a binder for refractory cements, imparting volume stabiUty and strength in ceramic materials for electrical condensers, foundry and glassmaking molds, and sand molds for metal castings (219—223). 

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