Automobiles ceramics

Catalytic Support Body Monolithic Honeycomb Unit. The terms substrate and brick are also used to describe the high geometric surface area material upon which the active coating material is placed. Monolithic honeycomb catalytic support material comes in both ceramic and metallic form. Both are used in automobile catalysts and each possesses unique properties. A common property is a high geometric surface area which is inert and does not react with the catalytic layer. 

There has been a rapid growth of the demand for plastics from less than 20 billion pounds in 1970 to nearly 50 billion pounds consumed in the United States in 1986, mostly due to the substitution of traditional raw materials. All over the world, plastics have replaced metals, glass, ceramics, wood papers, and natural fibers in a wide variety of industries including packaging, consumer products, automobiles, building and construction, electronics and electrical equipment, appliances, furniture, piping, and heavy industrial equipment [57-121]. Consumption patterns of PBAs in some countries are shown in Tabies 1 and 2. 

FIGURE 13.37 The catalytic converter of an automobile is made from a mixture of catalysts bonded to a honeycomb ceramic support. 

Within your lifetime, extraordinary changes will sweep through modern technology. Classes and ceramics are two of the advanced materials that will make these changes possible. Optical fibers—which are already playing a major role in communication—will control our computers, and our automobiles will be much lighter and more economical. 

The stability of ceramic materials at high temperatures has made them useful as furnace liners and has led to interest in ceramic automobile engines, which could endure overheating. Currently, a typical automobile contains about 35 kg of ceramic materials such as spark plugs, pressure and vibration sensors, brake linings, catalytic converters, and thermal and electrical insulation. Some fuel cells make use of a porous solid electrolyte such as zirconia, Zr02, that contains a small amount of calcium oxide. It is an electronic insulator, and so electrons do not flow through it, but oxide ions do. 

In this particular example as in many others, a proper analysis of cost is a crucial factor. An example is the production of balls for ball bearings. Coated ball bearings (or monolithic silicon nitride) greatly outperform steel balls but their cost is considerably higher. Steel balls in passenger-automobile applications are satisfactory and normally last the life of the car and the far-longer life of the ceramic balls is not needed. 

Asbestos-containing material Asbestos fibers Automobile tires Car fluff Ceramic waste Coal wastes... 

Uses. Storage batteries paint ink ceramics automobile radiator repair ammunition... 

Like the natural iron oxide pigments, the synthetics are used for colouring concrete, bitumen, asphalt, tiles, bricks, ceramics and glass. They are also used extensively in house and marine paints. Because the shapes of the particles can be accurately controlled and the particle size distribution is narrow, synthetic iron oxides have a greater tinting strength than the natural ones and so, are chosen where paint colour is important, i. e., for top coats. Red iron oxides are used in primers for automobiles and steel structures. 

The modem catalytic converter installed on most automobiles is a washcoat consisting of precious metal oxides, supported on a ceramic monolith. After passage of the... 

Also in an industry where weight and space are at a premium ceramic substrates occupy a larger volume than would a unit of comparable catalytic activity manufactured using Fecralloy as the substrate. In the relatively short time that the alloy has been available for large scale evaluation it has already gained acceptance by many potential users in the automobile industry and, as a result, specialty steelmakers both in the U.S.A. and Britain are now able to offer tonnage quantities in various fabricated forms. 

Monolith reactor This type of reactor is used extensively for the abatement of automobiles exhaust emissions. The gas flows continuously through the reactor, whereas the catalyst is a continuous phase consisting of a ceramic support and the active phase, which is dispersed onto the support. The support is structured in many channels and shapes that achieve large catalytic surface at small volume. A typical application of monolith reactors is the exhaust gas cleaning. 

What advantages do ceramic automobile engines have over metal ones ... 

Converters now in use contain noble metals on a ceramic substrate (e.g., platinum dispersed on alumina). The convener is typically located in the exhaust system in one of two general locations an underfloor location, or a close-coupled location near (he manifold. The operating temperature range lor noble metal catalyst is from 600 In I200 F (316 lo 649 C). which is similar to the exhaust pipe skin temperature range normally encountered or standard automobile engines. 

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