Inscriere cercetatori

On the influence of austenitization on the morphology of alpha-phase in tempered Cu-Zn-Al shape memory alloys

Domenii publicaţii > Stiinte ingineresti + Tipuri publicaţii > Articol în revistã ştiinţificã

Autori: Leandru-Gheorghe Bujoreanu

Editorial: Elsevier, Materials Science and Engineering A, 481-482, p. 395-403, 2008.


The paper reports some austenitization effects on the -phase morphology in a tempered martensitic Cu-21.57 Zn-7 Al (wt.%) shape memory
alloy (SMA). By means of differential scanning calorimetry, X-ray diffraction and optical and electron microscopy, it has been shown that the
effects of the stress-state induced in austenite persist even after martensitic transformation and tempering at 773 K. The two analyzed austenitization
states, hot-pressed and homogenized, respectively, aimed to reproduce two steps of an industrial technologic flow for SMA manufacturing.
Basically, austenitic hot-working diminished the size of disoriented -phase precipitates while austenitic homogenization enabled the formation
of a Widmanst¨atten structure with oriented long -phase needles, among which those corresponding to (1 1 1) intersect at about 70◦ and those
corresponding to (200) at 90◦.

Cuvinte cheie: Revenire retinuta; Incercari de educare-ciclare la incovoiere; Formarea bainitei; Faze stabilizate; Formarea preferentiala a fazei alpha // Constrained recovery; Training-cycling tests in bending; Bainite formation; Stabilized phases; alpha-Phase preferred formation