| Summary: | 碩士 === 南臺科技大學 === 機械工程系 === 105 === Pulse anodizing is a technique that can inhibit Joule heat accumulation. Compared to conventional DC anodizing, it can be carried out at room temperature (25 ° C). It can make the aluminum alloy surface to achieve high gloss. The anodic oxide layer has a flat interface layer to improve the mechanical properties. Therefore, this study used this technique for surface treatment of 7003 aluminum alloys. This article compared the pulse DC anodized surface treatment for 7003 aluminum alloy. The experiment is divided into three parts. Respectively, pulse waveform, anodizing parameters and pulse cycle. Investigated the effects of these experimental parameters on the optical properties, microstructure and mechanical properties of anodic oxide. The first part discusses the effects of pulse waveforms. The result is single pulse (SP) that can most effectively inhibit Joule heat accumulation, so the anodic oxide layer has excellent quality. The second part is to adjust the electrolyte concentration and current density. Use a 0.8 ASD constant current at 25 ° C for different electrolytic temperatures. When the concentration of electrolyte is 50 g / L, the anodic oxidation reaction reaches the most stable state. And then use 50 g / L of the electrolyte concentration with different current density, it was found that 0.8 ASD current density produced a small amount of Joule heat, can make the anodic oxidation reaction to balance. As can be seen from the above, at an electrolysis temperature of 25 ° C, using 50 g / L electrolyte concentration with 0.8ASD current density parameters. Can produce the best properties of the anodic oxide layer. The experimental results show that the pulse anodizing treatment, the same glossiness as DC can be prepared at room temperature (25 ° C) and has good mechanical properties. The optimal parameters for the use of single pulse (SP) at 50 g / L electrolyte concentration with 0.8 ASD with 5: 5 (s) pulse period. This parameter can effectively inhibit the Joule heat accumulation, and can achieve a stable anodic oxidation reaction, so the anodic oxide layer grows steadily and can improve the quality. The last part explores the effects of pulse cycles of 5 seconds, 10 seconds and 15 seconds at 50% ratios. The results show that the cycle is 15 seconds also achieve high gloss and increase the hardness. But the anodic oxide layer had a corrosion defect and reduced adhesion.
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