EFFECT OF DEFORMATION ON EXTINCTION OF ULTRASOUND IN MOLYBDENUM AND NIOBIUM MONOCRYSTALS (VPLYV DEFORMATSIYI NA ZAHASANNYA ULTRAZVUKU V MONOKRYSTALAKH MOLIBDENU I NIOBIYU),
Abstract
The paper aims to explain the effect of deformation on ultrasound damping in single crystals of Mo and Nb in the form of cylinders and cubes of zone purity with planes removed and heated to 1100C for several hours to relieve polishing stress. Measurements were made at 10 and 30 Mc by the pulse method of crystals deformed by compression perpendicular to the (100) plane and recorded the ultrasonic damping as a function of deformation. In molybdenum slight deformation results in great damping with a maximum at 1% deformation and leveling off at 2%, which is attributed to shortening and widening of the dislocation loop. Ultrasonic damping in Nb rises linearly at both frequencies with no maximum at room temperatures. This is attributed to intense restoration of elastic properties. Further experiments showed restoration of damping in a single crystal of Mo to be insignificant, while it is more pronounced in the deformed Nb specimens. Temperature dependence of the damping factor in single Nb crystals was also studied and found to be of the same order as deformation changes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 16, 1967
- Accession Number
- AD0836591
Entities
People
- M. S. Mordyuk
Organizations
- National Air and Space Intelligence Center