ACOUSTIC TESTS OF ELASTIC AND MICROPLASTIC PROPERTIES OF V-TI-CR ALLOYS

The non-linear acoustic properties of V-10Ti-5Cr alloy before and afte r proton irradiation (dose 2.2 x 10(14) p/cm(2)) were investigated usi ng a composite oscillator technique at longitudinal vibration frequenc ies of about 100 kHz. Acoustic parameters (decrement and resonance fre quency) of the samples demonstrated noticeable amplitude dependencies of hysteretic type both in undeformed and deformed states. An unusual influence of plastical pre-straining on irradiated sample was found wh ich resulted in small decreases in damping and increases in resonance frequency, and hence, of the elastic modulus. Damping in an irradiated sample was higher and its resonant frequency was lower as compared wi th a non-irradiated sample. This acoustic effect correlated with the r esults of microhardness and yield strength measurements. The experimen tal results are discussed in the framework of a model which predicts t he creation by proton irradiation of defects which aid the motion of d islocations in V-alloys.