In the Part 4 of this report, we discussed about the effects of voltage and concentration on the properties of anodic oxid film which is formed by the alternating current sulphuric acid process for 40 minutes. In succession to the preceding experiments, We examined in this report the effects of time and concentration on properties of anodic oxid film in alternating current sulphuric acid process. In this experiments, time is varied from 20 to 60 minutes, concentration is varied from 10 to 30% and the other factors are held in constant, i. e., voltage is 15V, and, and temperature of bath is 15°±1°C. The inspection methods for the properties of oxid film are the methods specified in JIS P 10431, 1951, which were used in the preceding experiments.
The results of experiments are as follows.
(1) The relation between thickness of film and time and concentration is shown by following experimental formula. (See Fig. 1., Fig. 2, Fig. 3 and Table 2.) T=(0.037C+0.056)t+0.05C+1.1 (10<C<30 20<t<60) (T=Thickness(μ) C=Concentration(%) t=Time(min.))
(2) The relation between thickness of film and electric power is shown by following experimental formula. (See Fig. 4, Fig. 5 and Table 3.) T=(0.0065t+0.09)W+0.035t+0.6 (10<C<30 20<t<60 0.6<A/dm
2<1.4) (W=Electric Power (A/dm
2×V))
(3) The relation between corrosion resistance and time and concentration is shown by following experimental formula. (See Fig. 6, Fig. 7, Fig. 8 and Table 4.) 1/S=a5.21/t+b5.2 (10<C<30 20<t<60) (S=Corrosion Resistance (Sec.)) Coefficients, a
5.2 and b
5.2 vary with concentration as shown in Fig. 8.
(4) The relation between abrasion resistance and time and concentration is shown by following experimental formula. (See Fig. 9, Fig. 10 and Table 5.) A=(0.21C-0.7)t-2(C+1) (10<C<30 20<t<60) (A=Abrasion Resistance (sec.))
(5)The relation between abrasion resistance and thickness of film is shown by the same experimental formula as reported in the Part 4 of this report. (See Fig. 13.) A=30T-100 (3<T<15)
(6) The relation between abrasion resistance and electric power is shown by following experimental formula. (See Fig. 11, Fig. 12 and Table 6.) A=(0.313t-2)W-2(0.7t+1) (10<C<30 20<t<60 0.6<A/dm
2<1.4)
(7) Specific abrasion resistance increases with time and concentration. (See Fig. 14.)
