Corrosion behaiver of CuZnAl shape memory alloy in three different media

Abstract

Copper based shape memory Alloys are interesting group of metal alloys that have
a widespread potential in medical and industrial applications . Cu-based shape memory
alloys of Cu-22Zn-4Al alloy as master alloy have been prepared by powder metallurgy
technique with and without the addition of( 0.2 and 0.4) wt.% of Zr. After mixing the
powders for 5hr, the alloys were prepared using 650MPa compact pressure. Thealloys
were subjected to sintering process in vacuum tube furnace with three steps. Several tests
such as microstructures observation and phase analysis using scanning electron
microscope, and X-ray diffraction analysis have been done. Electrochemical corrosion tests
for alloys with and without the addition of(Zr) was carried out usingpotentiodynamic
polarization techniquein three different solutions (HCl,NaOH,NaCl). XRD
andmicrostructural analysis showed that all alloys compositions consisted of the
predominating Cu5Zn8 phase.Corrosion test results have showed that the highest corrosion
resistance was found in the addition of (0.4 wt.% Zr) which give the lowest corrosion rate(
30.31mpy) in 3.5% NaCl solution.Noted that the corrosion rate of base alloy was
(86.88)mpy