Kv. Sapozhnikov et Sb. Kustov, ACOUSTOPLASTIC EFFECT AND AMPLITUDE-DEPENDENT INTERNAL-FRICTION DURING DEFORMATION OF IMPURE ALUMINUM SINGLE-CRYSTALS, Journal de physique. IV, 6(C8), 1996, pp. 293-296
Time, temperature, plastic strain, strain rate and oscillatory stress
amplitude dependences of the acoustoplastic effect and dislocation amp
litude-dependent absorption of ultrasound causing this effect have bee
n studied during three-point bending of aluminium single crystals. The
acoustoplastic effect was observed not only during macroplastic defor
mation, but during microplastic deformation on ''elastic'' loading and
during strain recovery on unloading as well. The time dependence of t
he acoustoplastic effect shows two components: ''fast'' (time-independ
ent) and ''slow'' (time-dependent). Data obtained evidence for the dis
tinction in defect structure levels responsible for the acoustoplastic
effect and amplitude-dependent internal friction. Dislocation - dislo
cation interaction is suggested as a basic source of the acoustoplasti
c effect. Dislocation - point defect interaction plays a secondary par
t in mechanism of the acoustoplastic effect, even in case of dynamic s
train ageing.