Isothermal decomposition of the Cu–22.72Al–3.55Be at.% alloy

Kinetics of isothermal decomposition in polycrystalline β CuAlBe alloys

“…A similar behaviour has been reported for the Cu-22.71Al-2.57Be (at%) alloy [19]. However, other authors have reported the formation of g 2 phase as the first precipitate in Cu-22.72Al-3.55Be (at%) [7] and Cu-22Al-3Be (at%) [6] alloys. If attention is focused on the Be content, the sequence of phase transformation does not exhibit a clear trend in the mentioned alloys, and no explanation can be definitively given about which phase will first nucleate.…”

“…These shapes would present a better crystallographic adjustment with the matrix, minimizing the superficial tension [5]. Since the a 0 phase is richer in copper than the b phase [6,7], the matrix surrounding the a 0 particles is depleted in copper. In those zones, after 48 h aging at 670 K, the presence of g 2 phase and eutectoid embryos, corresponding to alternated plates of a 0 and g 2 phase, is observed.…”

“…If attention is focused on the Be content, the sequence of phase transformation does not exhibit a clear trend in the mentioned alloys, and no explanation can be definitively given about which phase will first nucleate. Nevertheless, the formation of a 0 or g 2 phase increases or decreases the aluminum and beryllium content of the matrix respectively [6,7], promoting the formation of the other phase. Thereafter the final microstructure in all case is the eutectoid (a 0 þ g 2 ).…”

Effect of γ2-phase precipitates on the martensitic transformation of a β-CuAlBe shape memory alloy

“…For higher fvg 2 , the cycles become flatter, and the critical transformation temperatures increase. The The g 2 composition has been estimated as Cu-27.9Al-4.6Be (at%) [17], being richer in Al and Be than b phase. Consequently, g 2 precipitation depletes the matrix of these elements.…”

Effect of Deformation on the Transformation Temperatures of Martensite and Bainite Structures in Cu-9.97%Al-4.62%Mn Alloy

“…Three transformations were observed; one during heating and three during cooling. These peaks correspond to reverse β 1 → β 1 + γ 1 transformation and (β → α + γ 2 ) eutectoid decomposition [7][8][9][10]. The β ordered austenite undergoes an eutectoid decomposition where equilibrium state, at slow cooling, in copper-based alloys [11].…”