本研究主要是以A356.2、Al-7Si以及Al-7Cu做為實驗材料，選用六種不同的鹽類（KF、NaF、KCl、NaCl、K2CO3以及Na2CO3）做為鋁合金熔煉時的除渣劑（Flux）。經加入除渣劑後的不同組成的鋁湯，分別備製實驗組(加除渣劑)與對照組(不加除渣劑)的鋁合金冷激片、減壓片、水平和ASTM B108模試棒。鑄後冷激片經拋光後，調查除渣製程前後與鋁合金元素 (Si、Cu和Mg等)對冷激片夾雜物顆粒數量和尺寸分佈的影響。上述相同的冷激片置於超音波震盪後，診斷與分析除渣製程前後與鋁合金元素 (Si、Cu和Mg等)對冷激片中霧化區（氧化膜或孔洞）型態、尺寸與分佈的綜合影響。並比較除渣製程前後對不同鋁合金試棒的機械性質的影響。而除渣反應過程所收集到的浮渣則利用x-ray來分析。 最後實驗結果顯示: *除渣製程的處理，對於鋁合金冷激片中霧化區（氧化膜或孔洞）形態的影響，依序為：氟化物 > 氯化物 > 碳酸物。 *由影像分析統計資料，顯示經除渣製程處理後，在相同組成的鋁湯內，其對夾雜物顆粒(孔洞)數量的影響，數量由高至低依序為：碳酸物（156 counts/mm2）> 氯化物（145 counts/mm2）> 氟化物（132 counts/mm2）。 *觀察發現氟化物反應所產生的浮渣較為碎裂，浮渣的型式屬於乾渣。氯化物反應所產生的浮渣多為塊狀和片狀，浮渣的型式屬於濕渣。使用碳酸物與鋁湯反應方面，浮渣都呈現團塊狀的情形。 *經由X-ray粉末繞射分析後，顯示出A356.2合金分別使用KF和KCl反應後的浮渣，分別含有K3AlF6和KAlSiO4化合物;在Al-7Cu方面，使用K2CO3反應後，所產生的浮渣含有Cu2MgO3和K6MgO4化合物;在Al-7Si方面，分別使用KF和NaF反應後，所產生的浮渣分別為K3AlF6和Na2SiF6化合物。 *散佈在試棒中的氧化膜和夾渣物，會降低試棒的機械性質。 Effect of fluxing chemicals on the quality of the aluminum castings were fully assessed and discussed in this study. Six different fluxing chemicals classified into three groups(fluorides, chlorides and carbonates) were added to A356.2, Al-Si and Al-Cu melts respectively. The quality of aluminum castings was evaluated by the oxide particles and oxide films on polished surface of aluminum chill samples (after ultrasonic vibration treatment). The inclusion particles and oxide films (termed as foggy area of polished surface from aluminum chill samples) were statistically assessed by pc-meter image process system. Alloying elements on the quality of aluminum castings were commonly different while it was strongly dominated by the fluxing chemicals. Experimental results showed that the morphologies of foggy areas (or porosity) on the aluminum chill samples were mainly controlled by the orders of fluorides, chlorides and carbonates. The average of inclusion particles was 156, 145 and 132 (counts/mm2) through the image process system after fluxing with fluorides, chlorides and carbonates in each melts, respectively. The skimmed slag was also observed and detected after fluxing treatment. The dry-type dross was found in fluxing melts with fluorides when the others were wet-type fluxed by the chlorides and carbonates. Many spontaneously reactive and complex compounds were detected by the X-ray powder diffraction spectroscopy. Eventually, the optimal fluxing process was achieved through the mechanical properties testing of fluxed specimens. Keyword: fluorides, chlorides, carbonates, fluxing treatment, inclusion particles, oxide films, dry-type slag, wet-type slag
