Internal friction and anelastic properties of vanadium and V–Ti–Cr alloys

Using an acoustic technique of composite oscillator, the effect of preliminary deformation on the amplitude dependence (amplitude range from 10−6 to 3 × 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 studied. The alloys differed in composition, manufacture technology and also irradiation type (protons, neutrons), environments and fluence were varied. Neutron irradiation (fast reactor, BR-10) of the samples was carried out in argon (irradiation temperature TI=410°C) and liquid lithium (TI=480°C) environments. It has been found that, for anelastic deformations of the order of 10−8–10−6, irradiation may result in most cases in noticeable anelastic softening of alloys characterized by a Young's modulus decrease. The softening of the V–4Ti–4Cr alloy irradiated in Ar appeared to be the most significant. The experimental results of acoustic studies might be explained by changing the mobile dislocation point defect interaction, perhaps additionally influenced by existing internal stresses.