Effect of creating hole corrosion process on the specific capacitance of capacitors anode foil

The creating corrosion test of high purity aluminium foil was carried out in different condition under the H2SO4-HCl corrosion system,then enlarging corrosion 600s in 85℃ enlarging etching solution at 0.15 A/cm2 DC current condition,after formation treatment,the specific capacitance of the foil was measured by static capacity tester.The effect regularity of HCl concentration,current density,time and temperature on the specific capacitance of the foil were studied,and the morphology of corrosion holes were analyzed by SEM.The results show that,with c(HCl) increases,the specific capacitance increases firstly and then decreases,when c(HCl)= 2.0 mol/L,the specific capacitance reaches its maximum;the effect regularity of current density,time and temperature on the specific capacitance are similar to c(HCl),the specific capacitance reaches maximum corresponding to current density,time and temperature is 0.6 A/cm2,80 ℃and 140 s respectively.When c(HCl) 3 mol/L and current density 0.7 A/cm2,the corrosion foil presented obvious combining hole phenomenon.