Physical characteristic of copper (II) sulphate (Cu(II) SO4) etchant on aluminium etching

Abstract

Chemical etching is a process applies a strong chemical solution, called etchant to the surface of a workpiece to gradually remove any unwanted workpiece material. Basically, it is corrosion controlled process and is an irreversible chemical reaction. It is widely used as a nontraditional machining process to produce a geometrically complex and dimensional accurate component. Chemical etching is a useful process to reduce the excess mass of a workpiece material. In this study, Aluminium (Al) was etched in a solution of Copper(II) Sulphate (Cu(II) S04) and Sodium Chloride (NaCl) where Cu(II) S04 act as the limiting reactant or etchant for the electrochemical reaction to occur. The beneficial using this etchant is that there is no production of harmful gases compared to etching with mineral acids such as nitric and hydrochloride acid. The chemical etching of Al was carried out using single side immersion etching method where the Al samples were purposely mounted in epoxy resin with an exposed area of 4 cm 2 for efficient grinding and polishing. The experimental study of the chemical etching of Al was conducted at different etching temperature and also at different concentration of the etchant. The parameter on the selected chemical etching effects on the depth of etch, weight loss, and also the surface finish quality of the Al were investigated. As a result, It was observed that Cu(II) S04 has a fast etch rate and was a useful etchant for Al. When the etching temperature and the etchant concentration increase, the Al etches rate increase, tend to have a greater depth of etch and weight loss which also results in a better surface quality.