Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/91901
標題: CaCO3/Ca3(SiO4)O 為主的粉末混摻 SiO2/脫硫渣改 質物應用於鎂合金抗蝕阻熱之研究
CaCO3/Ca3(SiO4)O powder mixed with SiO2/ modified desulfurization slag for improving the anti-corrosion and heat resistance ability of AZ91D Magnesium alloy
作者: 張鈞然
Jiun-Ran Chang
關鍵字: 鎂合金;脫硫渣;阻熱;抗腐蝕;AZ91D;desulfurization slag;anti-corrosion;heat resistance
摘要: 
Magnesium alloys have low density and high strength/weight ratio. These characteristic make magnesium alloys being a potential candidates to replace steel and aluminum alloys in many structural and mechanical applications especially in vehicle application. However, magnesium alloy has high electrochemical activity, and therefore a poor corrosion resistance. Besides, magnesium alloys have poor mechanical properties at high temperature. Accordingly, usage of magnesium alloys are not yet widespread.
In this study, using CaCO3/Ca3(SiO4)O powder mixed with SiO2 or modified desulfurization slag spraying on the surface of AZ91D. That could improve the anti-corrosion and heat resistance ability of AZ91D. The spray coating layer contain more SiO2 percentage which has better anti-corrosion and heat resistance ability. The
result of experiment show that the spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After 96 hours salt spray test, the spray coating
containing 16 wt.% SiO2 corrosion area less than 5%. The adhesion strength of spray coating layer containing 16 wt.% SiO2 is 0.92 MPa. By the result of cross cut test, the spray coating layer containing 16 wt.% SiO2 reached 4B level. On the other hand, the spray coating layer contain more modified desulfurization slag percentage has better anti-corrosion and heat resistance ability. The spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After the 96 hours salt spray test, the spray coating contains 24 wt.% modified desulfurization slag corrosion area less than 5%. The adhesion strength of spray coating layer containing 24 wt.% modified desulfurization slag is 1.18MPa. By the result of cross tape test the spray coating layer
containing 24 wt.% modified desulfurization slag reached 4B level.

鎂合金具有高比強度,應用於需輕量化的載具中。但鎂合金應用受限於化學活性高抗腐蝕性差且熔點低,在高溫下易失去強度。若能同時增加鎂合金的阻熱和抗蝕能力,將有助於增加鎂合金的應用層面。另一方面,鋼鐵材料是應用最廣泛的結構材料之一,但是在鋼鐵精煉的過程中會有脫硫渣的產生。因脫硫渣呈強鹼性且含有未完全反應的氧化鈣(Free-CaO),不能將其隨意丟棄或掩埋,會對環境造成嚴重的危害。因此,本研究嘗試將脫硫渣的 Free-CaO 含量降低,將其應用於提升抗蝕阻熱性能。將脫硫渣改質物或 SiO2 混摻 CaCO3/Ca3(SiO4)O 為主的抗蝕阻熱粉末並與水混合成漿料,將其噴覆在鎂合金 AZ91D 上。由實驗結果顯示,抗蝕阻熱噴覆層能增加 AZ91D 的阻熱能力。且 SiO2 含量越高阻熱效果越好,含 16wt.% SiO2 的噴覆層熱擴散係數低於 AZ91D 基材 88%。相較於 SiO2,噴覆層中添加脫硫渣改質物會使熱擴散係數上升,但含 24wt.% SiO2 的噴覆層熱擴散係數仍然低於 AZ91D 基材 50%。由密度測量結果可知,噴覆層中 SiO2 含量越高導致密度越高,與 AZ91D 基材相比增幅 2.6%,仍然保持鎂合金低密度的特性。
由極化結果顯示,抗蝕阻熱噴覆層能大幅降低腐蝕電流密度至 30 μA・cm-2,顯示噴覆層能有效降低腐蝕速率,且添加 SiO2 或脫硫渣改質物能使腐蝕電流密度再次下降。由鹽霧試驗結果顯示,於抗蝕阻熱噴覆層中添加 24wt.%的脫硫渣改質物的抗腐蝕能力優於含有 16wt.%的 SiO2 的噴覆層。由噴覆層與 AZ91D 結合力試驗結果顯示,噴覆層陰乾時間越長與 AZ91D 結合力越強。且噴覆層中添加 SiO2導致噴覆層與 AZ91D 的結合力降低,但於抗蝕阻熱噴覆層中添加 24wt.%的脫硫渣改質物與 AZ91D 會有最大的結合力 1.18MPa。根據百格測試結果,噴覆層陰乾時間越長與 AZ91D 的附著性越好,且噴覆層中添加越多的 SiO2 百格等級越好,可達到 4B 等級。另外,於抗蝕阻熱噴覆層中添加 24wt.%的脫硫渣改質物與AZ91D 的附著性和添加 16wt.%SiO2 噴覆層同為 4B 等級
URI: http://hdl.handle.net/11455/91901
其他識別: U0005-2906201510402300
Rights: 同意授權瀏覽/列印電子全文服務,2018-07-16起公開。
Appears in Collections:材料科學與工程學系

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