Compositions: ceramic – Ceramic compositions – Refractory
Patent
1994-02-03
1995-05-09
Group, Karl
Compositions: ceramic
Ceramic compositions
Refractory
501153, C04B 3510
Patent
active
054139732
ABSTRACT:
A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly.
REFERENCES:
patent: 3531308 (1970-09-01), Bagley
patent: 3990902 (1976-11-01), Nishizawa et al.
patent: 4543346 (1985-09-01), Matsui et al.
patent: 4584157 (1986-04-01), Matsui et al.
W. F. Eppler, "Uber das Hartem Sgnlhetischer Spinelle", Angew. Mineral 4:345-362, 1943.
M. H. Barnes, "Synthetic Sapphire and Spinel Reduction in Germany", Tech. Rept. F.I.A.T. 655: pp. 1-17, 1945.
J. G. Grabmeier et al., "Strength of Flame-Fusion-Grown Magnesium-Aluminum Spinel", J. Am. Ceram. Soc. 52:645-650, 1969.
C. C. Wang, "Growth and Characterization of Spinel Single Crystals for Substrate Use in Integrated Electronics" J. Appl. Physics 40:3433-3444, 1969.
P. F. Becher, "Press-Forged Al.sub.2 O.sub.3 -Rich Spinel Crystals for IR Applications", Am. Ceram. Soc. Bull. 56:1015-1017, 1977.
H. Saalfeld et al., "Die Entmischung Al.sub.2 O.sub.3 -Oberscattigter Mg-Al Spinelle", Z Kristallgor. 109:87-109, 1957.
M. H. Lewis, "Precipitation in Nonstoichiometric Spinel Crystals", Phil. Mag. 20:985-998, 1969.
"Magnesium Aluminate Spinel", Phil. Mag. 29:709-722, 1974.
W. F. Eppler, "Bearing Jewels of Hardened Synthetic Spinel", F.I.A.T. Final Report #1038, pp. 1-40, 1947.
A. Mangin et al., Abstract of: Cont. Rend. 242:1893-1895, 1956 (Chem. Abst. vol. 50, #11757H, (1956).
A. Lejus et al., "Formation of a Metastable Intermediate Phase During the Decomposition of a Nonstoichiometric Spinel", Cont. Rend. 251:959-961, 1960 French Original and English abstract (Chem. Abstr. vol. 55, #21483B (1960).
D. Lewis et al., "Precipitation and Toughness in Aluminum-Rich Spinel Single Crystals", Fracture Mechanics of Ceramics, vol. 8, Plenum Press, N.Y., pp. 61-68 (in press) no date.
Y. Akimune et al. "Knoop Microhardness Anisotropy of Single-Crystal Stoichiometric MgAl.sub.2 O.sub.4 Spinel", J. Am. Ceram. Soc. 70:C84-C86 1987 no month.
Donlon et al., "Precipitation in Non-Stoichiometric Spinel", J. Of Mat. Sci. 17 (1982) pp. 1389-1397.
Bansal et al., "Precipitation Strengthing In Non-Stoichiometric Mg-Al Spinel", Fracture Mechanics of Ceramics, vol. 2, pp. 677-690 (1974).
Dixon Harold M.
Group Karl
Moser William R.
The United States of America as represented by the United States
Tumm Brian R.
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