Precision blanking of thin sheet metals with the help of chemical etching

It is difficult to separate small parts precisely from thin sheet metals by press blanking. This study describes a countermeasure to the problem by combining press forming and chemical etching. A 0.1 mm beryllium copper sheet was indented along a cut profile and subjected to etching, resulting in separation of the part surrounded by the indented line. Etching time to complete separation was considerably reduced compared with the ordinary etching process. Shape of indented portion also affected the etching time. Two indenting methods were tested in combination with two masking methods. SEM observation showed that every test condition provided a good cut edge having a smooth and fracture-free surface although some thickness reduction or dissolution of the cut edge occurred depending on masking methods.