アルミニウムの陽極酸化皮膜に及ぼす加工条件の影響(第6報)

硫酸皮膜交流電解に於ける電解液温度および電解電圧の影響について

抄録

In the Part 4 and Part 5 of this report, we discussed about the effects of voltage and concentration and time on the properties of anodic oxide film which is formed by the alternating current sulphuric acid process.
In this Part, we examined the effects of bath-temperature and voltage on properties of anodic oxide film in alternating current sulphuric acid process. In this examinations, bath-temperature is variede from 10 to 30°C, voltage is varied from 10 to 20 V and the other factors are held in constant, i. e., concentration is 20% and time is 40 minutes. The inspection methods for the properties of oxide 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 bath-temperature and voltage is shown by following experimental formula. (See Fig. 2, Fig. 3, Fig. 4 and Table 2.)
T=0.845e (0.0392h+1.035V)
(10<h<25 10<V<20)
[T=Thickness (μ) h=Bath-temperature (°C)V=Voltage (V)]
When the bath-temperature reaches 30°C., this formula can not be applied because of the severe corrosive attack of sulphuric acid.
(2) The relation between thickness of film and electric power is shown by the same formula as in the Part 4. (See Fig. 5.)
T=1.8+0.35W
(10<h<25 10<V<20 time=40mins)
[T=Thickness (μ) W=Electric power (A/dm₂×V)]
When the bath-temperature reaches 30°C., this formula can not be applied.
(3) The relation between corrosion resistance and bath-temperature and voltage is shown by following experimental formula. (See Fig. 6, Fig. 7, Fig. 8, and Table 3.)
S=(20.2-0.27h)e (0.0036h+0.022)V
(10<h<25 10<V<20)
[S=Corrosion resistance (sec.) h=Bath-temperature (°C.) V=Voltage (V)]
When the bath-temperature reaches 30°C., this formula can not be applied.
(4) "Specific corrosion resistance" (corrosion resistance for unit thickness of film) of the film is reduced as the bath-temperature rises and the reducing rate is higher in the lower voltage than in higher voltage. In comparison with the D. C. anodizing method, this reducing tendency of "specific corrosion resistance" is more remarkable in the A. C. anodizing method. (See Fig. 9)
(5) The relation between abrasion resistance and bath-temperature and voltage is shown by following experimental formula. (See Fig. 10, Fig. 11, Fig. 12 and table 4.)
A=1.59e (0.0533h+0.23V)
(10<h<20 10<V<20)
[A=Abrasion Resistance (sec.) h=Bath-temperature (°C.) V=Voltage]
At the bath-temperature of 25°C. and 30°C., this formula can not be applied.
(6) The relation between abrision resistance and thickness of film is shown by the same experimental formula as reparted in the Part 4 and Part 5 of this report. (See Fig. 14.)
A=30T-100 (10<h<20 3<T<15)
[A=Abrasion Resistance (sec.) T=Thickntiss (μ)]
At the bath-temperature of 25°C, and 30°C., this formula can not be applied.