Consolidation and properties of porous Cu–Al–Ni shape memory alloys manufactured by powder metallurgy

A.P. GOMEZ; G. URRETAVIZCAYA; A. BARUJ; M.T. MALACHEVSKY

POWDER METALLURGY

Taylor & Francis

Lugar: London; Año: 2023

0032-5899

A method to manufacture a porous Cu–Al–Ni shape memory alloy by powder metallurgy usingspace holders is presented. Two aluminium powders with different particle morphologies wereemployed to investigate their influence on phase formation, microstructure and mechanicalproperties. The variation of the relative amount of space holders in the mixture allows toobtain different porosities. Samples prepared with irregular-shaped aluminium powderinclude both 18R and 2H martensitic phases and exhibit the shape memory effect andpseudoelastic behaviour under uniaxial compression tests. In contrast, the samples madewith aluminium flakes present the α phase accompanying the 18R martensitic phase, anddo not exhibit the shape memory effect. Both the aluminium flakes flat shape and thehigher proportion of aluminium oxide associated with its larger surface area to volume ratiohindered the interdiffusion of the metals, resulting in an aluminium-depleted martensiticphase surrounded by an aluminium oxide-rich layered structure.