Cutting alumina-based ceramics

Masuda, M., Sato, T., Kori, T. and Chujo, Y. (1994) Cutting performance and wear mechanism for alumina-based ceramic tools when machining austempered ductile iron. Wear 174 147-153. 

Kumar AS, Durai AR, Somakumar T (2006) The effect of tool wear on tool life of alumina-based ceramic cutting tools while machining hardened martensitic stainless steel. J Mater Process Technol 173(2) 151-156... 

In contrast to the above proposals, it is likely that other advanced ceramics-notably alumina, beryllia, sihcon carbide and sUicon nitride (see Chapter 11)-will demonstrate below-average growth rates owing to environmental concerns, competition from other ceramics (see Table 6.4), and an increasing reUance on slower-growing market segments such as cutting tools that are based on ceramic alloys (e.g., modified alumina and SiAlONs). In this situation, whilst alumina will surely remain the prominent material, its market share wiU be eroded by ferrites, and by beryllia- and zirconia-based ceramics. 

In assembling hybrid microcircuits or multichip modules, ceramic interconnect substrates fabricated using thin-film or thick-film processes are attached to the inside base of a ceramic or metal package. Generally, film adhesives that have been cut to size are used to attach large substrates (greater than 1-inch square) while either paste or film adhesives may be used for smaller substrates. Substrates may be alumina, beryllia, aluminum nitride, or silicon. 

Plain oxide ceramics do not enable economical machining of luckel base materials, due to their poor resistance to thermal shock and low firacture toughness. Alumina oxide with titanium-carbide, so-called mixed ceramics, was successful applied with cutting velocities up to 500 m/min for turning operations (Wiemann 2006). 

Ceramics, particularly new ceramic composites, are widely used in the cutting-tool industry. For example, alumina reinforced with silicon carbide whiskers (extremely fine fibers) is used to cut and machine cast iron and harder nickel-based alloys. Ceramic materials are also used in grinding wheels and as abrasives because of tiieir exceptional hardness (Table 12.4). Silicon carbide is the most widely used abrasive. 

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