The preparation and properties of some lithium zinc silicate glass-ceramics |
| |
Authors: | I. W. Donald B. L. Metcalfe D. J. Wood J. R. Copley |
| |
Affiliation: | (1) Atomic Weapons Establishment, Aldermaston, Berkshire, UK;(2) School of Materials Science and Physics, Thames Polytechnic, London, UK;(3) School of Chemical Physics, University of Bristol, Bristol, UK |
| |
Abstract: | Lithium zinc silicate glasses are of interest for the preparation of moderately high thermal expansion glass-ceramics which are suitable for sealing to a number of nickel-based superalloys. The effect of composition, in particular the variation of nucleating species, on the crystallization behaviour of a number of these glasses has been examined using differential thermal analysis, X-ray diffraction, and electron microscopy. Various crystal phases have been identified, including cristobalite, quartz, tridymite and0 Li2ZnSiO4. In addition, most of the glass-ceramics also contain an unidentified phase which may be related to the-series of lithium zinc silicates. Heat-treatment schedules have been derived on the basis of these results in order to produce a number of glass-ceramic materials. The resultant thermal expansion characteristics of the glass-ceramics have been monitored using dilatometry, and expansions in the range 12.3 to 17.1×10–6° C–1 (20 to 460° C), have been obtained, depending on the precise glass composition and heat-treatment schedule employed. In addition, the mechanical properties of a number of selected samples have been monitored, employing a biaxial flexure technique. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|