Effect of hydrogen on the temperature dependence of the elastic constants of tantalum single crystals

Journal Article · Sat Jan 01 04:00:00 EST 1977 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.323327· OSTI ID:7330857

Stewart, III, W L; Roberts, J M; Alexandropolous, N G; Salama, K

An investigation was undertaken to determine whether or not a significant Snoek relaxation mechanism exists when hydrogen is dissolved in tantalum. The experimental approach involved the determination of the changes in the absolute values and the temperature (in the range 136--298 degreeK) dependence of the elastic constants of single crystals charged with varying amounts of hydrogen up to 10.3 at %. Changes in the absolute values of the elastic constants, as a function of hydrogen concentration, were found to be linear, with positive slopes for C/sub 11/, C/sub L/, and C/sub 44/, and a negative slope for C'. The small negative slope of C' yields the distortion parameter (lambda/sub 1/-lambda/sub 2/) value of 0.0274. The bulk modulus and the Voight average Young's modulus were found to increase when hydrogen was introduced into the crystal lattice. The elastic constants exhibit no change in their temperature dependence when either the temperature (in the range 245--298 degreeK) or the hydrogen concentration (in the range 0--10.3 at.%) was varied. It is concluded that a Snoek relaxation attributed to tetrahedral symmetry of the locally distorted tantalum cubic lattice by hydrogen is insignificant. (AIP)

• Research Organization: Department of Materials Science, Rice University, Houston, Texas 77001
• OSTI ID: 7330857
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 48:1; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
CRYOGENIC FLUIDS
CRYSTALS
ELASTICITY
ELEMENTS
FLUIDS
FRICTION
HYDROGEN
INTERNAL FRICTION
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
MONOCRYSTALS
NONMETALS
REFRACTORY METALS
STRESS RELAXATION
TANTALUM
TEMPERATURE DEPENDENCE
TENSILE PROPERTIES
TRANSITION ELEMENTS
YOUNG MODULUS