The structure–phase transformations and mechanical properties of the shape memory effect alloys based on the system Cu–Al–Ni

Abstract

The effect of the alloying with 9 to 14 wt % aluminum and high-temperature thermo-mechanical treatment on the structure–phase transformations in ternary Cu-Al-Ni shape memory effect (SME) alloys has been studied using methods of optical and electron microscopy, electron and X-ray diffraction analysis. The obtained results have demonstrated the possibility of the dendrite substructure elimination and prevention of an embrittlement-providing decomposition in cast alloys upon certain thermo-mechanical external action via employment of the processes of controlled recrystallization in an austenite state and subsequent quenching. The authors have established specific features of the improvement of the mechanical properties, grain structure of β austenite, and microstructure of the β’1 and the γ’1 martensite in dependence of the chemical composition of alloys and their thermo-mechanical treatment.