| Title |
Research Paper / Surface Treatment : A Study on Zinc Immersion Deposition of Semi - liquid Formed AZ 91 HP Magmesium alloys |
| Authors |
김세광(Shae Kwang Kim); 한혜준(He Won Han); 한범석(Beom Suk Han); 김영직(Young Jig Kim) |
| Abstract |
Magnesium alloys have received an increasing amount of attention in recent years due to their exceptionally low densities and high specific strengths. Among various manufacturing methods for magnesium alloys, semi-liquid forming has advantages of near net shape and the safety over inflammable magnesium alloys. The objective of this paper was to produce a electroplating base for semi-liquid formed AZ91HP magnesium alloy, consisting of activations and zinc immersion deposition. The variations of the surface potentials with time were conducted both during activations and zinc immersion deposition. The results indicate that oxalic/chromic activation sequence can produce a good foundation for zinc immersion deposition and by the double-dip technique, thin and homogeneous zinc immersion deposits can be obtained in shorter time compared with the normal single-dip technique. The growth mode of zinc immersion deposits largely depends on the surface potential deviations caused by the differences of microstructures and phases. |