Ceramics, wear

Aircraft engines Ceramic turbine nozzles in the APU (Auxiliary Power Unit Engine). Seals runners installed in different business jets such as Falcon, Citation and Learjet. Ceramic oil pump spacer enhance engine could start capability on APUs on Boeing 777 and 737 and all Airbuses. Cutter pins, which are used as a safety feature for air turbine starters. Ceramic wear indicator on Airbus APU starter brushes since 1997... 

Srinivasan, S., and Scattergood, R.O. (1991), Rcurve effects in solid particle erosion of ceramics , Wear, 142, 115-33. 

He went on to say that the main problem is that ceramics wear too slowly to release sufficient solid lubricant. This is certainly a major problem, but another important difficulty is what might be called a mis-match between the temperature capabilities of the ceramics and of the more common solid lubricants. The greatest value of ceramics is for temperatures above 350°C, where steel loses its hardness, many non-ferrous metals become very soft, and only a few polymers can be used even for very short periods. Unfortunately this is also the temperature at which even the most stable of the common solid lubricants have limited lives except in vacuum or inert atmospheres. 

The Chemical Dictionary defines porcelain as "ceramic wear made largely of baked clay (kaolin) coated or glazed with a fusible substance." Kaolin is defined as "(china clay white bole argilla porcelain clay white clay). A whiteburning clay, which, due to its great purity, has a high fusion point and is the most refractory of all clays." It gives the composition as "mainly kaolinite (40% alumina, 55% silica) plus impurities and water."... 

ZS-7. [Advanced Refractory Tech.] 2ir-coniumdibotide for oxidation-resistant composites, burnable absorber of neutrons, elec, contacts, molten metal crucibles, refractory toughener, cuttit tool composites, structural ceramics, wear components, metal matrix composites. 

Mechanical ceramics Wear protection ceramics Resistant to abrasion Thread guides, linings, tubes, roll ... 

Abrasive ceramics Wear-resistant Grinding wheels... 

Andersson, P., Water-lubricated pin-on-disc tests with ceramics. Wear, 1992. 154 p. 37-47. 

The exit ports from the feed zone are themselves subject to a considerable range of designs and innovations. It is not usual to have just one exit port. For symmetry and balance an even number of ports is usual, two, four, six or eight. The basic design has these ports fitted with tubular nozzles, often lined with a ceramic wear protection. 

A type of tile construction. The ceramic wear plate has a triangular spigot on its back face mating with a triangular recess on the front face of the backing plate to which it is bonded or brazed. II provides support and extra safety should the bond or braze fall... 

Ceramic wear is more of the abrasive type and is characterized by the generation of debris giving rise to propagation of cracks in type 1 and II mixed (opening and straight sliding). It increases drastically above the critical load. 

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