Method for thermal processing alumina-enriched spinel single crystals

Patent · 09 May 1995

OSTI ID:46308

Jantzen, C M

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. 12 figs.

• Research Organization: E I Dupont De Nemours & Co Inc
• DOE Contract Number: AC09-76SR00001
• Assignee: Dept. of Energy, Washington, DC (United States)
• Patent Number(s): US 5,413,973/A/
• Application Number: PAN: 8-190,940
• OSTI ID: 46308
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
HEAT TREATMENTS
MAGNESIUM OXIDES
MECHANICAL PROPERTIES
MICROSTRUCTURE
MONOCRYSTALS
OPTICAL PROPERTIES
SPINELS