| Summary: | The correlation of the thermomechanical parameters and chemical composition, which enables to determine the phases providing properties related to reliable, recoverable strain, was studied for three Cu-(21.6–25.4)Zn-(3.3–5.6)Al alloys. The conventionally cast samples were hot forged and cold-rolled, followed by quenching in different media and aging treatment. The alloy A with low aluminum content (3.3%) has exhibited better tensile strength and elongation than B and C samples, in addition to good low-temperature workability and refined grain. The stress plateau recorded on the stress–strain curve during tensile testing of quenched specimens was related to the recoverable strain of up to 4.2%. Most of the examined specimens have shown shape memory recovery above 90%. The apparent activation energy for microhardness increase in the examined alloys during aging at 200 °C–500 °C for up to 30 h was (55.3 ± 3.9) kJ mol−1 compared with (55.7 ± 4.6) kJ mol−1, which was recorded for the decrease in shape memory recovery. These results suggest a common origin for both changes. The precipitate was formed along the grain boundaries and the matrix. Neither the coarsening of α-precipitate nor γ-precipitate was observed during the aging of examined alloys for up to 30 h. Martensite stabilization was avoided in A and B alloys as a result of the step quenching treatment. A relatively short life expectancy was predicted for alloy C, while good shape memory properties may be expected for alloys A and B during their exposure to temperature up to 50 °C.
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