Experimental investigation of the pseudoelastic behavior on zirconium modified Cu-Al-Be shape memory alloys for seismic applications

This paper examines the effect of 0.05-0.3 wt.% of zirconium-doping on microstructure, transformation temperatures, tensile properties, and pseudoelastic behavior of the parent beta(1)-phase Cu-87.93-Al-11.5-Be-0.57 shape memory alloys (SMAs). Results reveal that alloying zirconium in the evaluated SMA samples exhibits an excellent grain refinement up to 0.15 wt.%. Further, higher additions of Zr >= 0.2 wt.% lowers the grain refinement efficiency due to precipitates agglomeration. Larger the size and volume fraction of Al3Zr precipitates led to higher transformation temperatures. Tensile properties were improved with Zr-doping, resulting enhancements in the maximum tensile strength and ductility with the addition of 0.15 wt.% Zr. The alloy with 0.05 wt.% of Zr-dope showed a good pseudoelastic strain recovery of deformation strain and then lowered by retaining large residual strain, indicating deterioration in the pseudoelasticity of SMAs.