Ambient temp. phosphating - using accelerator contg. bath to produce coating espec. amenable to accepting electrophoretic paint coatings

摘要

The workpieces, of Al, Zn or Fe base materials are treated in a Zn-Mn phosphate soln. contg. 0.1-30 mg/l Cu ions, pref. the grm. atom ratios of Zn : Cu and Zn : Mn being respec. 100-1500 and 3-15 resp. The bath has a free acid value of 0.1-0.5 and the accelerator is espec. in the form of a nitrate, nitrie or chlorate.