高溫鉬酸銨溶液預浸置處理對鋁陽極氧化膜的影響

THE INFLUENCE OF PRE-IMMERSING IN HIGH TEMPERATURE SOLUTION OF AMMONIUM MOLYBDATE ON THE ANODIC FILM OF ALUMINUM

陳瑰瑋(Kuei-Wei Chen)

指導教授 ： 施幸祥

大同大學/工程學院/化學工程學系所/碩士(2004年)

摘要

本研究主要目的在研究高溫鉬酸銨及氟化銨混合溶液預浸置處理過程中，鉬酸銨濃度、浸置時間及浸置溫度對陽極氧化皮膜性質之影響。結果發現較高的浸置溫度有助於水氧化鉬膜的生長。除此之外，浸置時間及鉬酸銨濃度對水氧化鉬膜的生長也有很大的影響，但對於陽極氧化膜膜厚卻無正面影響。適當的水氧化鉬膜膜厚有利於陽極氧化膜硬度的提升，但太厚的水氧化鉬膜會抑制陽極氧化膜的增長，對硬度沒有明顯的幫助。由SEM，當浸置溫度超於80℃時，不會形成孔洞小且分佈均勻的陽極氧化膜，這對氧化膜硬度是沒有幫助的。此外由EDS及ICP分析知，氧化膜中含有鉬離子，證明鉬為增加陽極氧化皮膜硬度的理由之一。腐蝕測試證明經80℃之預浸置溫度可得到最佳抗腐蝕之陽極氧化膜。當浸置條件為0.025 mol/L 鉬酸銨，於80℃浸置40分鐘，而陽極氧化之電流密度為5A/dm2，可得到最高硬度約627HV之陽極氧化膜。

關鍵字

鉬酸銨 ； 陽極氧化膜 ； 溶膜試驗 ； 高浸置溫度

並列摘要

The main purpose of this research is to study the effects of the ammonium molybdate concentration, immersing time and immersing temperature on the anodic films of aluminum sheets which was pre-immersed in the solution that contains ammonium molybdate and ammonium fluoride at high temperature.
The higher immersing temperature surely promote the formation rate of molybdic oxyhydroxide film. Except the immersing temperature, the immersing time and ammonium molybdate concentration do effect the molybdic oxyhydroxide film thickness very much but not the anodic film thickness. Appropriate molybdic oxyhydroxide film thickness would be conducive to obtain a harder anodic film. But too thicker molybdic oxyhydroxide film will inhibit the growth of anodic film.From SEM, it can be known that the immersing temperature over 80℃ can not make the pores on the anodic film smaller and distributed uniformly. It’s not helpful for film hardness. The EDS analytic chart show that the molybdenum atom is found in the anodic film, it’s one reason why the anodic film microhardness increases. From ICP test, it also reveals that the concentration of Mo is helpful for the anodic film hardness. From corrosion test, the anodic film obtained through an immersing temperature of 80℃ has the best corrosion-resistance.Under the immersing conditions of 0.025 mol/L ammonium molybdate, 80℃, 40 min and an anodizing current density of 5A/dm2 (p.c.), a maximum anodic film microhardness of 627 HV can be obtained.

並列關鍵字

Ammonium molybdate ； anodic film ； dissolution test ； high immersing temperature

參考文獻

[2] D. R. Gabe and I. H. Dowty, Surf. coat. technol., 30(1987)309.

[3] S. Wernick and R. Pinner, The Surface Treatment and Finishing of Aluminum and its Alloy, Vol. 1(1972)297.

[5] H. Konno, Y. Baba and R. Furuichi, Mat. Sci. Forum, 192/194(1995)379.

[6] F. Keller, M. S. Hunter and D. L. Robinson, J. Electrochem. Soc., 100(1953)411.

[7] G.E. Thomson, Thin Solid Films 297(1997)191.