Amplitude-dependent internal friction of molybdenum single crystals

Journal Article · Mon Oct 01 04:00:00 EDT 1973 · J. Phys., F (London), v. 3, no. 10, pp. 1789-1795

DOI:https://doi.org/10.1088/0305-4608/3/10/014· OSTI ID:4385309

Sklad, P S; Gibala, R; Mitchell, T E

The amplitude-dependent internal friction of several highpurity molybdenum single crystals was examined at approximately 100 kHz over the temperature range 4.2 to 300 deg K. The specimens were oriented near the centre of the stereographic triangle and were deformed in tension at 156 and 450 deg K. Increasing the magnitude of the applied strain amplitude was found to increase the background damping in all specimens and to produce an - alpha peak in some instances. The occurrence of the alpha relaxation peak was found to depend on the presence of an optimum dislocation configuration, internal stresses, and applied strain amplitude. The optimum dislocation configuration appears to be one of edge-type segments present after small amounts of deformation and under the influence of locally high internal stresses. Other segments apparently achieve this or other optimum configurations after much larger amounts of plastic deformation when the overall internal dress level is higher. Results are interpreted in terms of the depinning of kinks trapped by point defects as the likely mechanism of the alpha peak. (auth)

• Research Organization: Case Western Reserve Univ., Cleveland
• NSA Number: NSA-29-005515
• OSTI ID: 4385309
• Journal Information: J. Phys., F (London), v. 3, no. 10, pp. 1789-1795, Journal Name: J. Phys., F (London), v. 3, no. 10, pp. 1789-1795; ISSN JPFMA
• Country of Publication: United Kingdom
• Language: English

Related Subjects

*MOLYBDENUM-- INTERNAL FRICTION
AMPLITUDES
BORDONI PEAK
DAMPING
DEFORMATION
EDGE DISLOCATIONS
KHZ RANGE 01-100
LOW TEMPERATURE
MEDIUM TEMPERATURE
MONOCRYSTALS
N50230* --Metals
Ceramics
& Other Materials--Metals & Alloys--Properties
Structure & Phase Studies
RELAXATION
STRAINS
STRESSES
TEMPERATURE DEPENDENCE
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE