Effect of Ti on Corrosion of Cast AZ91 Magnesium Alloy
Ti addition to AZ91 alloy was been investigated with conventional casting. The Corrosion resistance of all the different Ti addition content alloy was studied in 3.5% NaCl solution through weight loss measurement in constant immersion conditions and potentiodynamic polarization experiments.The results show that addition of Ti with an amount of 0.1~0.8wt% the corrosion resistant of alloy was improved. In the case of AZ91-0.8Ti alloy had minimum corrosion rate value , AZ91-0.4Ti alloy had minimim corrosion current density. After Ti added into alloy, the morphology of β phases was changed, TiAl3 intermetallics appeared. The inhibiting effect of the β phases and TiAl3 intermetallics in the AZ91-Ti alloy predominated in the long period immersion testing, but during short interval of electrochemical testing galvanic corrosion effect in the AZ91-Ti alloy predominated.
X. L. Ai et al., "Effect of Ti on Corrosion of Cast AZ91 Magnesium Alloy", Advanced Materials Research, Vols. 311-313, pp. 1457-1461, 2011