摘要 本研究主要以A356.2、Al-7Si及連續鑄造A356.2合金為實驗材料，使用石墨除氣棒進行除氣，並選用KCl和NaCl混合物(組成成份為44%和56%)做為鋁合金熔煉時的覆蓋劑(flux)。分別備製有無添加覆蓋劑施予除氣處理的鋁合金冷激片、減壓片、船型水平模試棒。將鑄後冷激片經拋光處理後，調查除氣與除渣製程處理對鋁合金成份的冷激片孔洞(介在物)數量與尺寸分佈影響。再將拋光處理後的冷激片進行超音波洗淨器震盪，診斷除氣對除渣製程處理後與鋁合金成份和冷激片霧化區(氧化膜)分佈型態、尺寸的影響。利用X-ray分析除渣處理後所產生的浮渣種類和形態。並比較除氣處理後鋁合金試棒的疲勞性質與微孔(介在物)和氧化膜的相關影響。 實驗結果顯示： 不同的除氣方式，使用石墨除氣棒可以明顯降低冷激片微孔(介在物)數量和霧化區(氧化膜)面積率。 使用除氣和fluxing處理後，冷激片微孔(介在物)數量會增加，而霧化區(氧化膜)面積率則減少。 Fluxing和除氣處理後，形成浮渣，收集的渣有不同的成份和形態。以低鍶A356.2合金而言，浮渣呈現團聚狀。以高鍶A356.2合金而言，浮渣呈現小塊狀。以Al-7Si合金而言，浮渣則呈現片狀。 進行X-ray 粉末繞射分析後，高、低鍶A356.2合金的浮渣含有KAlSiO4。Al-7Si合金的浮渣則含有KAlSiO4、Na2O。 隨著微孔(介在物)的數量與尺寸增加，試棒疲勞壽命會明顯的降低。 Abstract The purpose of this study is aimed at investigating effect of pore count and foggy mark area in different aluminum melts after degassing and fluxing treatment. The alloys used in this study are A356.2 alloys, Al-7Si alloys and continuous cast A356.2 alloys. Use lance for degassing treatment. Cover fluxes are mixture of KCl and NaCl, which at 44% and 56%. After fluxing treatment, analysis the type and morphologies of slag by the X-ray powder diffraction spectroscopy. Experimental results indicated that degassing treatment by lance resulted in decreasing pore count and foggy mark area in the melts. Adding cover flux would increase pore count and decrease foggy mark area. The slag was also observed and detected after fluxing treatment. The wet-type dross was found in fluxing melts with KCl and NaCl. Eventually, fatigue life would decrease, if the pore count and size of inclusion in alloys increase.
