Phase transformations during continuous cooling of polycrystalline â-CuAlBe alloys

SUSANA MONTECINOS; ADELA CUNIBERTI; M.L. CASTRO; ROBERTO BOERI

JOURNAL OF ALLOYS AND COMPOUNDS

ELSEVIER SCIENCE SA

Año: 2009 vol. 476 p. 278 - 283

0925-8388

The transformations during continuous cooling and their effect on the thermoelastic behaviour of -CuAlBe shape memory alloys have been studied by electrical resistometry, microscopy and differential calorimetry. Under slow cooling rates, the alloys show hypereutectoid behaviour asa result of the addition of Be. The sequence of 2 and  precipitation and the ordering of phase were clearly identified. A quasi-binary phase diagram with variable Be content is proposed. Small modifications in the Be content cause noticeable changes in the ranges of phase stability. The precipitation could be avoided with high cooling rates. The precipitation processes produce changes in the matrix composition, which affect the critical temperatures of ordering as well as the -martensite transformation.2 and  precipitation and the ordering of phase were clearly identified. A quasi-binary phase diagram with variable Be content is proposed. Small modifications in the Be content cause noticeable changes in the ranges of phase stability. The precipitation could be avoided with high cooling rates. The precipitation processes produce changes in the matrix composition, which affect the critical temperatures of ordering as well as the -martensite transformation.