Research And Development On Advanced Graphite Materials. Vol V - Analysis Of Creep And Recovery Curves For ATJ Graphite

Item

Title
Research And Development On Advanced Graphite Materials. Vol V - Analysis Of Creep And Recovery Curves For ATJ Graphite
Date
1961
Index Abstract
Contrails and DTIC Condensed
Photo Quality
Not Needed
Report Number
WADD TR 61-72 Volume V
Creator
Seldin, E. J.
Draper, R. N.
Corporate Author
National Carbon Company, Inc.
Laboratory
Directorate of Materials and Processes
Extent
44
Identifier
AD0270536
AD0270536
Access Rights
OTS
Distribution Classification
1
Contract
AF 33(616)-6915
DoD Project
7350
DoD Task
73503
DTIC Record Exists
Yes
Distribution Change Authority Correspondence
None
Abstract
Flexural creep tests were made on specimens of ATJ graphite at temperatures ranging from 2300° to 3000°C. The creep curves have been fitted by graphical and analytical means to four equations. Fairly good fits have been obtained with all of the equations which were used. Attempts were made to determine the stress and temperature dependence of several of the parameters in the equations

Of the four equations which were used, one could be related to simple rheological models having some physical significance. A model was found useful not only in describing the creep curves, but also in describing the recovery after creep and relating the behavior in recovery to the behavior during creep. Generally good agreement was found between the qualitative predictions of the models and the observed behavior. Using a model, an activation energy for the steady state creep rate was determined to lie between 70 and 76 kcal/mole. Some deviations were detected between the actual behavior of the material and that predicted by the simple models which suggest some modifications that may be made to obtain a better model. The value of a model is discussed, and several additional experiments are suggested to supplement the information given by creep experiments.
Report Availability
Full text available
Date Issued
1961-09
Subject
Creep
Graphite
High Temperature
Mathematical Analysis
Stresses
Theory
Viscosity
Publisher
Wright-Patterson Air Force Base, OH : Aeronautical Systems Division, Air Force Systems Command, United States Air Force
Distribution Conflict
No
Provenance
Lockheed Martin Missiles & Fire Control
Type
report
Format
1 online resource