Enstatite glass-ceramics

Three different mechanisms and types of processing were used by Echeverrfa and Beall (1991) to develop enstatite-type glass-ceramics  

After the heat treatment, the glass-ceramics contained enstatite and tetragonal zirconia as the primary crystal phases. Glass-ceramics with a composition of 43.7 wt% Si02  

Zr02 crystallized according to the mechanism of surface crystallization The surface crystallization was so dominant that the final glass-ceramic material demonstated very high stress buildup in the surface area 

Flexural strength 250 MPa, WeibuU modulus 11.2, flexural modulus 160 GPa, fracture toughness 3.3 MPa m -, and fracture surface energy 51 J/m  

This type of glass-ceramic material is used to make circuits in the electronics industry. 

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Figure 4-5 Spinel-enstatite glass-ceramic as a magnetic memory disk substrate, in comparison to a canasite disk and a nickel-spinel glass-ceramic.

Li Si O enstatite [14681-78-8] MgSiO diopside [14483-19-3], CaMgSi O and woUastonite [14567-57-2], CaSiO. A number of sihcate glass-ceramic compositions are given in Table 1. 

Fig. 2. RepHca electron micrograph of the fracture surface of enstatite—P-spodumene—zirconia glass-ceramic, showing twinning in the enstatite grains...

Figure 2-12 Microstructure of enstatite- 3-spodumene glass-ceramics showing lamellar twinning in enstatite.

Pure spinel glass-ceramics show other properties distinct from enstatite-spinel glass-ceramic. These include spinel glass-ceramics and are characterized by GTE of 3.4 X 10 K (0 C-300°C) and transparency in the visible spectrum. They are also suitable for the production of highly pol-ishable disk substrates (Fig. 4-5) (Pinckney 1999). 

All four types of glass-ceramics (spinel-enstatite, spinel, lithium disilicate, and canasite) have been produced by Corning Inc., USA. 

Gutzow I., Zlateva K., Alyakov S., and Kovatscheva T, "The Kinetics and Mechanism of Crystallization in Enstatite-Type Glass-Ceramic Materials," J. Mater. Sci., 12, 1190-202 (1977). 

Echeverrfa L.M. and Beall G.H., "Enstatite Ceramics Glass and Gel Routes pp. 235—44 in Ceramic Transactions, Vol. 20 Glasses for Electronic Applications. Edited by ICM. Nair. American Ceramic Society, Westerville, OH, 1991. 

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