Structure of Electrodeposited Zn-Mn Alloy Coatings
Structure of electrodeposited Zn–Mn alloys which are one of the corrosion-resistant zinc alloy coatings suitable for automotive body panels was investigated using X-ray diffraction, SEM and SIMS.<br>The coatings are composed of fine grains or granular grains which contain fine particles, depending on the Mn content. The coatings have an uniform depth distribution of Mn and Zn.<br>X-ray diffraction revealed that the coatings have either single or dual alloy phases which are the following phases, namely η phase, Γ phase, ε phase, γ-Mn phase and α-Mn phase, depending on the Mn content. The ε phase and γ-Mn phase as high temperature phases exist when the range of the Mn content is above 20 mass%. Both phases are stable when heated at 170°C. The γ-Mn phase is transformed to the β-Mnphase and the α-Mn phase by heating beyond 250°C, although the e phase is unchanged.
- ISIJ international
ISIJ international 40(10), 1024-1028, 2000-10-15
The Iron and Steel Institute of Japan