Abstract
A few well known methods of pretreatment for electro-plating on aluminium, are studied.
The results are as follows:
i) The best adhesive property of electro-deposit is obtained by the pretreatment in the nickel chloride bath, but the plated surface is slightly rough.
ii) The electron microscopic observation of the chemically treated surface revealed that the wavy structure is produced by zincate immersion, cleavage like structure by nickel chloride immersion and granular structure by other treatments. The deposit of granular structure is generally less adhesive.
iii) The adhesive property does not always depend on the electrode potential.
