Amplitude-dependent and amplitude-independent internal friction has be
en studied in martensite and during temperature induced martensitic tr
ansformation in CuAlNi single crystals after different heat treatments
. The measurements of intrinsic damping were performed in ultrasonic a
nd infrasonic frequency ranges. Low frequency measurements were combin
ed with the direct observations of the stress-anelastic strain hystere
tic loops. Observed regularities do not correspond to the breakaway mo
del of amplitude-dependent internal friction both for quenched and age
d samples. The conclusion is drawn, that during ageing in beta-phase t
he behaviour of the pinning obstacles changes from highly mobile at ro
om temperature and forming atmospheres around the mobile defects, pres
umably dislocations, to rather immobile and homogeneously distributed
in the bulk of the crystal. Amplitude dependent and amplitude independ
ent internal friction components, measured at ultrasonic frequencies,
exhibit different temperature dependences during direct martensitic tr
ansformation. A maximum of the non-linear anelasticity was observed ne
ar the M(s) temperature, implying a significant contribution of the pr
emartensitic phenomena to the amplitude-dependent internal friction du
e to phase transition.