Effects of titanium addition on mechanical and corrosion behaviours of AZ91 magnesium alloy

Abstract

The mechanical properties and corrosion behaviour of AZ91 magnesium alloy containing 0.2–0.5wt.%Ti were investigated in this study. Results demonstrate that the enhancement of the ultimate tensilestrength by 18% and yield strength by 47% can be achieved by Ti addition. The corrosion behaviour wasevaluated by immersion tests and potentiodynamic polarisation measurements in 3.5% NaCl solution.The results from the immersion tests and potentiodynamic polarisation measurements showed that thecorrosion resistance of AZ91 alloy increased progressively with the increase of the Ti content of the alloy.ComparedtoAZ91alloy,0.5Tiadditionincreasedthecorrosionresistancebyupto45fold.Themechanismof property enhancement is ascribed to both the suppression of partially divorced -Mg17Al12eutecticsand an increased Al content in -Mg solid solution by Ti addition in AZ91 alloy.