PT Journal
AU Bradac, J
   Sobotka, J
TI Influence of Draw-Beads Geometry on the Surface Quality of Zn-Mg Coating
SO Manufacturing Technology Journal
PY 2023
BP 758
EP 768
VL 23
IS 6
DI 10.21062/mft.2023.088
DE Zn-Mg coating; Draw-beads; Car body stampings; Electron microscope; Surface quality
AB In terms of surface protection of outer car body parts, zinc coatings are currently highly used in automotive industry. Concretely, hot dip galvanized (HDG) sheets are used in most cases. However, other possible alternatives such as zinc-magnesium coatings (Zn-Mg), which are usually referred to as ZM coatings, are also more frequently applied. Thanks to magnesium, the corrosion resistance is significantly increased, which also positively influences the coating thickness. On the other hand, the presence of magnesium makes this coating harder and brittle, which significantly limits its use to produce complex car-body stampings. To prevent the stamped material being drawn into certain parts of the drawing die, special types of draw-beads (so-called edge beads) are used. The effect of draw-beads geometry on the level of damage of ZM coating using experimental tests is evaluated in this article. For comparison, the same experiments were also done for HDG zinc coated specimens. Then the comparison of both methods using TESCAN MIRA3 scanning electron microscope was used and the level of damage of both tested coatings was assessed.
ER