| Title |
Corrosion Properties of Squeeze Cast Mg-5wt%Al alloy containing Zirconium |
| Authors |
박진영(Jin Young Park) ; 박주현(Joo Hyun Park) ; 홍준표(Chun Pyo Hong) ; 김도향(Do Hyang Kim) ; 박익민(Ik Min Park) |
| Abstract |
The effects of Zr addition and heat treatment on the corrosion properties of the squeeze cast Mg-5wt%Al alloy have been investigated by potentiodynamic polarization test, impedance measurement and immersion test in deaerated 3.5wt%NaCl solution. Mg-5wt%A1-0.6wt%Zr alloy was solution heat-treated at 415℃ for 24hrs and then artificially aged at 220℃ for 55hrs (T6). The results show that the Zr addition in the squeeze cast Mg-5wt%Al alloy increases the corrosion resistance mainly due to the grain refinement and uniform distribution of Mg_(17)Al_(12) phases. Heat treatment affects greatly the microstructures and corrosion properties of Mg-5wt%Al-0.6wt%Zr alloy. The corrosion resistance of Mg-5wt%Al-0.6wt%Zr alloy decreases in the order, T6, as-cast, solution heat-treated condition. The superior corrosion resistance in T6 heat-treated condition is considered to be due to the effective pit propagation barrier behavior of Mg_(17)Al_(12) discontinuous precipitates. |