Ceramics machining characteristics

Reinforcing aluminum alloys with ceramic fibers can provide a useful increase in elastic modulus (especially at elevated temperatures) and improve creep strength and heat erosion resistance. The disadvantages are decreased elongation to fracture and more difficult machining characteristics. 

Parks JR, Hill MJ (1959) Design of extrusion augers and the characteristic equation of ceramic extrusion machines. J J Am Ceram Soc vol 42 No Ipp 1-6... 

To establish the necessary characteristics for the abrasive belts and the machine tools, using them such that high stock removal can be achieved on ceramic materials while maintaining good output precision and surface quality. 

Some examples of the grain-size effect in ceramics are illustrated below Ti3SiC2 was chosen as one exemplar, since this ternary compound exhibits a unique combination of properties. It is a layered material that is as machinable as graphite. At the same time, CG (100-300 pm) samples of Ti3SiC2 have been observed to be damage-tolerant, not susceptible to thermal shock and oxidation resistant. The specimens are fully dense, bulk, single-phase polycrystalline samples of Ti3SiC2. This material exhibits brittle failure characteristics at RT, but is plastic at 1,300 °C with yield points of 300 and 100 MPa under compression and flexure, respectively. 

With regard to applications, these include mixing, aero- and hydrodynamics, heat dissipation and chemical reactions. One could use the features to, for example, change the location of transition from laminar to turbulent flow, or change the drag characteristics of a surface. Curved protrusions could be used to create swirl, and the holes could function as micro-injectors - even for chemicals - or to increase cooling. Surfl-sculpt could also function as a mechanical interlock. Shape memory alloys could also be improved in their functionality. Many materials could be processed in this manner metals, polymers, ceramics and glass are all feasible. The time to process 5 cm of material is a few seconds, and the equipment needed includes an electron beam machine and a vacuum chamber. 

By precipitating crystal phases in the base glass, however, new exceptional characteristics are achieved. Among these, for example, are the machinability of glass ceramics resulting from mica crystallization and the minimum thermal expansion of chinaware, kitchen hot plates, or scientific telescopes as a -... 

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