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Stress, Temperature, and Strain Rate in Creep of Magnesium Oxide
Author(s) -
HENSLER JOHN H.,
CULLEN G. V.
Publication year - 1968
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1968.tb13321.x
Subject(s) - creep , materials science , activation energy , magnesium , stress (linguistics) , exponent , power law , oxide , composite material , compression (physics) , strain rate , thermodynamics , metallurgy , chemistry , linguistics , philosophy , statistics , mathematics , physics
Hot‐pressed magnesium oxide was deformed in compression at stresses from 1000 to 6500 psi and at temperatures from 1200° to 1500°C. Steady state creep rates from 0.001 to 0.8%/hr were measured. The thermal activation energy was 105 ± 12 or 111 ± 12 kcal/mole, depending on the method of stress compensation used. A power law analysis for stress gave an exponent of 2.6 ± 0.6, and a stress activation analysis yielded a constant of (7.6 ± 1.4) × 10 ‐4 psi ‐1 . The statistical significance of all the constants is high. Deformations as large as 40% occurred, and no change in grain shape was detected. None of the available models for creep mechanisms are completely applicable to these results.