Title

Ultrasonic Methods in the Study of Fatigue and Deformation in Single Crystals of Aluminum and Sodium Chloride

Date

1963

Index Abstract

Coming Soon

Photo Quality

Not Needed

Report Number

ASD TDR 62-186

Creator

Chick, Bruce

Anderson, George

Findley, William

Elbaum, Charles

Truell, Rohn

Hikata, Akira

Corporate Author

Brown University

Laboratory

Directorate of Materials and Processes

Extent

37

Identifier

AD0408704

Access Rights

OTS

Distribution Classification

1

Contract

AF 33(616)-6945

DoD Project

7360

DoD Task

736002

DTIC Record Exists

No

Distribution Change Authority Correspondence

None

Abstract

The use of ultrasonic methods (and in some cases electrical conductivity measurements) for study ing defect formation and motion in connection with deformation and stress cling experiments in aluminum and sodium chloride single crystals is the subject. Recovery in aluminum single crystals at 195 K was compared with recovery at room temperature and an interesting 'threshold effect' was observed; there appears to be a level of deformation which must be exceeded at this temperature before recovery occurs. The auto matic recording time echo (or velocity) measure ment unit was designed to measure the time be tween two successive echoes in a pulse echo train with a sensitivity of one nanosecond out of one hundred microseconds and to record the measure ment as a voltage capable of driving a recorder so that dynamic changes in time will produce a record. It was found that no change in center frequency or bandwidth is seen over a 40 db range of gain control nor does an artificial change of 40 db in signal level produce a detect able change in measured time.

Report Availability

Full text available

Date Issued

1963-02

Provenance

Lockheed Martin Missiles & Fire Control

Type

report

Format

1 online resource