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Title: Method for thermal processing alumina-enriched spinel single crystals

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.

Inventors:
 [1]
  1. Aiken, SC
Issue Date:
Research Org.:
E I DUPONT DE NEMOURS & CO INC
OSTI Identifier:
869876
Patent Number(s):
5413973
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
C - CHEMISTRY C04 - CEMENTS C04B - LIME, MAGNESIA
DOE Contract Number:  
AC09-76SR00001
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; thermal; processing; alumina-enriched; spinel; single; crystals; process; age-hardening; alumina-rich; magnesium; aluminum; obtain; desired; combination; characteristics; hardness; clarity; flexural; strength; toughness; comprises; selection; time-temperature; pair; isothermal; heating; followed; quenching; selected; region; precipitate; sought; crystal; isothermally; heated; pass; phase; pre-precipitates; metastable; precipitates; stable; secondary; matrix; slowly; avoid; shock; rapidly; thermal shock; single crystal; single crystals; single phase; thermal processing; comprises selection; flexural strength; thermal heat; heating followed; phase precipitate; /501/

Citation Formats

Jantzen, Carol M. Method for thermal processing alumina-enriched spinel single crystals. United States: N. p., 1995. Web.
Jantzen, Carol M. Method for thermal processing alumina-enriched spinel single crystals. United States.
Jantzen, Carol M. Sun . "Method for thermal processing alumina-enriched spinel single crystals". United States. https://www.osti.gov/servlets/purl/869876.
@article{osti_869876,
title = {Method for thermal processing alumina-enriched spinel single crystals},
author = {Jantzen, Carol M},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1995},
month = {Sun Jan 01 00:00:00 EST 1995}
}

Works referenced in this record:

Knoop Microhardness Anisotropy of Single-Crystal Stoichiometric MgAl2O4 Spinel
journal, April 1987


Precipitation in non-stoichiometric magnesium aluminate spinel
journal, April 1974


Precipitation Strengthening in Non-Stoichiometric Mg-Al Spinel
book, January 1974


Strength of Flame - Fusion - Grown Magnesium - Aluminum Spinel
journal, December 1969


Die Entmischung Al 2 O 3 -übersättigter Mg - Al -Spinelle
journal, January 1957


Precipitation and Toughness in Alumina-Rich Spinel Single Crystals
book, January 1986


Precipitation in non-stoichiometric spinel crystals
journal, November 1969


Precipitation in non-stoichiometric spinel
journal, May 1982