ANELASTIC BEHAVIOR OF TANTALUM AND COLUMBIUM

Technical Report · Thu Nov 01 04:00:00 EST 1962

OSTI ID:4133907

Sneed, R J; Fink, E L; Abrams, M C

A theoretical model is developed based on dislocationinterstitial interaction during stress application, which describes the anelastic behavior of bcc metals particularly during yield delay. It is shown that the reorientation of interstitial impurities apparently controls both the preyield microstrain rate and the Lime to yield. The model is supported for tantalum and niobium by the results of yielddelay experiments over a temperature range from -97%DEF to 400 deg F. Activation energies of the yield-delay process, calculated both from microstrain rate data and time-to-yield information indicate that hydrogen diffusion has a controlling effect, with other interstitials contributing to the effective activation energies at the higher temperatures. Temperature- insensitive stress effects are noted. The model is further substantiated by x- ray diffractometry which demonstates the occurrence of anelastic lattice strains during load application and their consequent recovery. A brief resume is given on the initial efforts of a high-temperature study on the anelasticity in tantalum and columbium. This study is aimed at exploring anelastic behavior up to 3000 deg F. (auth)

• Research Organization: General Dynamics/Pomona. Div. of General Dynamics Corp., Pomona, Calif.
• NSA Number: NSA-18-005770
• OSTI ID: 4133907
• Report Number(s): ASD-TDR-62-323; AD-401811
• Country of Publication: United States
• Language: English

Related Subjects

BCC
DEFECTS
DEFORMATION
DIFFRACTION
DISLOCATIONS
ELASTICITY
EXCITATION
HIGH TEMPERATURE
INSTRUMENTS
INTERSTITIALS
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
NIOBIUM
RECOVERY
STRESSES
TANTALUM
TEMPERATURE
TENSILE PROPERTIES
X RADIATION