Effect of processing parameter on the quality of hot dip galvanising (HDG) coating
Loading...
Date
2019-05
Authors
Azfar Husni Bin Idris
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Zinc-aluminium alloy coatings have been used in certain atmospheric applications instead of zinc in this latest centuries. Three type of metal substrate, copper, aluminium and iron has been used to study the effect of process parameter on the quality of hot dip galvanising (HDG) coating. In this research an attempt have been made to study the effect of processing parameter on the quality of hot dip galvanising coating. The substrate were dipped into zinc-aluminium coating solution with 10 second, 20 second and 30 second dipping time. The coating solution were prepared by heat up zinc pellet at 650℃ in furnace. The molten zinc were then added with (0.1g, 0.2g, 0.3g, 0.4g, 0.5g, 0.6g, 0.7g) aluminium powder and cool to room temperature. Coated sample were characterized with corrosion test, TGA/DSC testing, Energy Dispersive X-ray (EDX) and Vickers microhardness test. The results revealed that Zn4Al exhibited the highest corrosion resistance for copper substrate, Zn-5Al for aluminium substrate and Zn-6Al for iron substrate. TGA/DSC was conducted to determine the melting temperature of the different coating composition for the maximum homogenity of molten zinc-aluminium during the coating process. The melting temperature was slightly different for 6 coating composition in Thermogravimetric Analyzer (TGA)/Differential Scanning Calorimeter (DSC) except for Zn-4Al. Hardness of the substrate was increased after been coated on the surface.