Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/9865
DC FieldValueLanguage
dc.contributor.advisor汪俊延zh_TW
dc.contributor.advisorJun Yen Uanen_US
dc.contributor.authorLee, Ching Feien_US
dc.contributor.author李青霏zh_TW
dc.date2004zh_TW
dc.date.accessioned2014-06-06T06:43:50Z-
dc.date.available2014-06-06T06:43:50Z-
dc.identifier.urihttp://hdl.handle.net/11455/9865-
dc.description.abstractAbstract Magnesium alloy has not been used as widely as aluminum, partly because of its poor corrosion resistance. In this study, aluminum and alumina thin film were deposited on the AZ91D substrate by radio frequency unbalance magnetron sputtering technique. The Mg17Al12 β film was formed due to solid diffusion between aluminum film and substrate after heat treatment. The alumina thin film was deposited on AZ91D substrate, and the alloy's corrosion performance was substantially improved. HF/H2SO4 pre-treatment is effective for reducing the Icorr value of die-cast AZ91D. Experimental results showed that Icorr decreases from 300μA/cm2 to 10μA/cm2 after pre-treatment. Aluminum film deposited on the pre-treated sample can not further decrease the Icorr value. Heat treatment for the Al film/pre-treated AZ91D sample was performed to obtain a Mg17Al12  phase right beneath the aluminum film. It was found that heating at 300℃ for 3hr will result in the formation of Mg17Al12 β phase. However, small cracks occurs while the sample cooling in air after heat treatment, leading to inferior corrosion performance. The sample will not have cracks while furnace cooling is carried out after heat treatment. The study found that a continuous β film covering the substrate will improve corrosion performance. Heating rate is an important factor to control the morphology of the β phase. When low heating rate was applied, β phase in irregular shape will form beneath the aluminum film, leading to severe corrosion. Alumina film with 100 nm in thickness, which can effectively protect the AZ91D alloy, resulting in high Ecorr (-0.7V) and low Icorr (0.428μA/cm2).en_US
dc.description.abstract摘要 本研究以非平衡磁控濺鍍的方式,沉積純鋁及氧化鋁薄膜於AZ91D基材上,以熱處理的方式藉由鋁膜與基材間的固態擴散產生β(Mg17Al12)相的連續膜,改善其腐蝕性質;而氧化鋁膜則是以短時間沉積極薄的膜達到其保護效果,並進行表面結構觀察及腐蝕特性等分析。 由實驗結果可知試片在經前處理後其腐蝕電流有明顯下降,約略由300μA/cm2降至10μA/cm2。而經前處理後的試片鍍純鋁膜的腐蝕電流與前處理後的試片相近,並無明顯改善。將鍍純鋁膜後的試片做300℃熱處理;當試片以空冷的方式冷卻,膜與基材會有裂縫產生,且腐蝕性質變差;試片以爐冷的方式冷卻,膜與基材不會有裂縫產生。由低掠角X-ray的分析得知300℃持溫3小時其β相的相對強度最強。實驗發現熱處理後β相的連續和緻密與否,對其Ecorr及Icorr有其影響。本研究藉由改變試片熱處理升溫速率,得知當升溫速率快其β相較為連續且緻密;當升溫速率慢其β相較為不連續且較不緻密。 鍍30min氧化鋁膜由SEM觀察其膜厚約略是100nm,而經由腐蝕實驗得知其腐蝕電位(約-0.7V)及腐蝕電流(0.428μA/cm2)均有明顯改善。故其鍍純鋁膜後熱處理與鍍極薄的氧化鋁薄膜均可改善其抗蝕性。zh_TW
dc.description.tableofcontents目錄 誌謝 I 中文摘要 II 英文摘要 III 目錄 IV 表目錄 VI 圖目錄 VII 第一章 緒論 1 1-1 前言: 1 1-2 研究目的 4 1-3 鎂合金的特性 5 1-3-1 鎂合金的分類法 5 1-3-2 鎂合金的熱處理 5 1-3-3 添加合金元素對鎂合金腐蝕之影響 6 1-3-4 第二相對鎂合金腐蝕之影響 7 1-4 極化曲線及腐蝕電流量測原理 8 1-5 濺鍍理論 9 1-6 PVD的應用 12 第二章 實驗步驟與方法 24 2-1 實驗流程 24 2-2 實驗材料及試片的前處理 24 2-3 表面粗糙度量測 25 2-4 薄膜沈積 25 2-5 熱處理 26 2-6 電化學測試法(electrochemical tests) 27 2-7 掃瞄式電子顯微鏡(SEM) 28 2-8 X-ray繞射分析 29 2-9 歐傑電子能譜儀 29 第三章 實驗結果 40 3-1 試片的前處理 40 3-2 改變鍍膜參數 41 3-2-1 SEM的觀察 41 3-2-2 鍍膜的X-ray實驗結果 42 3-2-3 鍍膜的腐蝕實驗結果 43 3-3試片熱處理 44 3-3-1 熱處理後X-ray實驗結果 44 3-3-2 熱處理後SEM的觀察 46 3-3-3 熱處理後的腐蝕實驗 47 3-4 氧化鋁鍍膜的結果 48 第四章 討論 81 4-1 酸洗活化前處理對降低Icorr原因探討 81 4-2 純鋁鍍膜及其對AZ91D Icorr, Ecorr之影響 83 4-3 熱處理 85 4-3-1 熱處理後空冷及爐冷 85 4-3-2 改變加熱速率之影響 87 第五章 結論 96 參考文獻 99zh_TW
dc.language.isoen_USzh_TW
dc.publisher材料工程學研究所zh_TW
dc.subjectRF unbalance magnetron sputteringen_US
dc.subject非平衡磁控濺鍍zh_TW
dc.subjectcorrosion propertyen_US
dc.subjectsolid diffusionen_US
dc.subjectcorrosion currenten_US
dc.subjectpre-treatmenten_US
dc.subject腐蝕性質zh_TW
dc.subject固態擴散zh_TW
dc.subject腐蝕電流zh_TW
dc.subject前處理zh_TW
dc.titleA Study on the Corrosion Properties of AZ91D Mg-Al-Zn alloy deposited Al and Al2O3 Films by Radio Frequency Unbalance Magnetron Sputtering Techniqueen_US
dc.title以射頻磁控濺鍍純鋁及氧化鋁薄膜於鎂合金表面之抗腐蝕研究zh_TW
dc.typeThesis and Dissertationzh_TW
item.fulltextno fulltext-
item.languageiso639-1en_US-
item.openairetypeThesis and Dissertation-
item.cerifentitytypePublications-
item.openairecristypehttp://purl.org/coar/resource_type/c_18cf-
item.grantfulltextnone-
Appears in Collections:材料科學與工程學系
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