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