INTERNAL-FRICTION AND ANELASTIC PROPERTIES OF VANADIUM AND V-TI-CR ALLOYS

Using an acoustic technique of composite oscillator, the effect of pre liminary deformation on the amplitude dependence (amplitude range from 10(-6) to 3 x 10(-4)) of ultrasound damping and the Young's modulus ( resonance frequencies) for V and V-(4-10)Ti-(4-10)Cr alloys has been s tudied. The alloys differed in composition, manufacture technology and also irradiation type (protons, neutrons), environments and fluence w ere varied. Neutron irradiation (fast reactor, BR-IO) of the samples w as carried out in argon (irradiation temperature T-I = 410 degrees C) and liquid lithium (T-I =480 degrees C) environments. It has been foun d that, for anelastic deformations of the order of 10(-8)-10(-6), irra diation may result in most cases in noticeable anelastic softening of alloys characterized by a Young's modulus decrease. The softening of t he V-4Ti-4Cr alloy irradiated in Ar appeared to be the most significan t. The experimental results of acoustic studies might be explained by changing the mobile dislocation point defect interaction, perhaps addi tionally influenced by existing internal stresses. (C) 1998 Elsevier S cience B.V. All rights reserved.