利用微弧氧化法探討電解液濃度的不同對7075-T6鋁合金陶瓷膜層之影響

The influence of electrolytic concentration on the peoperties of ceramic coating on 7075-T6 Al alloy by micro-arc oxidation

魯子駿(Tzu-jiun Lu)

指導教授 ： 楊木榮

大同大學/工程學院/材料工程學系所/碩士(2011年)

摘要

在許多表面處理技術當中，微弧氧化處理( Micro-Arc Oxidation；MAO)是一種新興的表面處理技術，此技術雖和傳統陽極處理 ( Anoding Oxidation )有些類似，但陽極處理製程程序長，且需使用大量強酸或強鹼電解液，對環境會造成破壞，反觀微弧氧化技術，製程簡單且使用對環境較不汙染的鹼性電解液，處理過後之試片表面所生成的陶瓷膜層的許多特性都優於陽極處理( Ex：抗腐蝕、耐磨耗、高硬度…等等)。鋁金屬具有質輕 ( 比重約2.7 )、高比強度、高耐磨耐蝕且易成型之特性，使輕金屬在近年來被廣泛應用於民生、汽車、航太或國防工業等方面。
本實驗是由雙極脈衝電源供應器控制電源參數，使用磷酸氫二鉀(K2HPO4)及氫氧化鉀(KOH)為電解液對7075-T6鋁合金進行微弧氧化處理。於處理時間20分鐘，磷酸氫二鉀粉末量為14g/L、16g/L及18g/L，可發現當電解液濃度提高，在低占空比，膜層表面破裂情況嚴重，而將占空比提高，會發現膜層表面有大面積的片狀燒蝕結構出現，當出現此類結構時，能有降低膜層粗糙度及提升耐蝕性。而對相組成而言，電解液濃度並未對其造成太大的改變，仍是由α-Al2O3和γ-Al2O3所組成。

關鍵字

抗腐蝕 ； 微弧氧化 ； 鋁合金

並列摘要

Micro-Arc Oxidation is a new surface coating technology, although this technique is similar to the traditional anodic coatings, traditional anodic coating is an many-step process and has to use many strong acid and alkali. It is not friendly to environment. Micro-arc oxidation is a simple process, and environment- friendly electrolytes are used only. The characteristic of ceramic coating is better than anodizing (for example, anti-corrosion, anti-wear, high hardness). Aluminum is well-known as light weight, high specific strength and easy to shape. Through suitable surface modification to improve its wear and corrosion resistance, it can be applied in wide application on commodity sector, automobile, aerospace and national defense industry.
In this work used by pulsed bi-polar power supply, the effect of concentration of the aqueous electrolytes (containing K2HPO4 and KOH) on MAO coating on 7075-T6 substrate was investigated. When the electrolyte concentration (among 14g/L, 16g/L and 18g/L) increased, at low duty ratio, it has seriously broken on the surface film; at high duty ratio, it can find many large area of re-melted shell on the film surface. This structure is beneficial to anti-corrosion and smoothness. Whether the electrolytic composition used in this study, the phases of MAO coatings of all samples are α-Al2O3 and γ-Al2O3.

並列關鍵字

anti-corrosion ； Micro-arc oxidation ； Al alloy

參考文獻

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