本文關(guān)鍵詞：鋁合金復(fù)合精煉技術(shù)研究　出處：《沈陽(yáng)理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 鋁合金 復(fù)合精煉 復(fù)合熔劑 除氣板 水模擬

【摘要】：鋁及其鋁合金在熔煉過程中不可避免地發(fā)生氧化吸氣并產(chǎn)生夾渣,嚴(yán)重降低機(jī)械綜合性能,影響鑄件的最終質(zhì)量。就此問題,本課題研究了多種復(fù)合式精煉技術(shù),通過對(duì)無(wú)機(jī)鹽各項(xiàng)性質(zhì)的研究,配比出作用不同且多功能的復(fù)合熔劑,并研制出適用于低壓鑄造機(jī)下爐使用的除氣板。分別通過鋁合金試樣密度值檢測(cè)法,減壓凝固試樣低倍組織針孔度檢測(cè)法,熱分析凝固冷卻曲線分析法,金相顯微組織觀察法。對(duì)復(fù)合精煉技術(shù)的凈化效果進(jìn)行評(píng)估判定,研究結(jié)果表明:在旋轉(zhuǎn)噴吹精煉的基礎(chǔ)上與自行研制的高效清渣劑復(fù)合凈化。從凈化效果來看,鋁合金密度增加,針孔度級(jí)數(shù)提升至一級(jí),致密性明顯提高,產(chǎn)渣量較少,比單一旋轉(zhuǎn)噴吹精煉凈化效果更好。研制的變質(zhì)清渣二元復(fù)合熔劑具有較好的變質(zhì)效果,變質(zhì)前與變質(zhì)后的共晶溫度之差可達(dá)到5.3℃,通過金相組織可知在變質(zhì)5min時(shí)為變質(zhì)效果最佳時(shí)間,硅的形態(tài)為細(xì)小均勻的纖維狀,變質(zhì)維持時(shí)間大約45min。清渣劑與精煉劑二元復(fù)合熔劑主要功效為除氣除渣,隨著熔劑加入量的增加,鋁合金液致密性逐步提高,經(jīng)扒渣夾渣成渣量也隨著熔劑劑量的增加而減少,該清渣、精煉二元復(fù)合熔劑除氣除渣效果較為顯著。三元復(fù)合熔劑集清渣、變質(zhì)、精煉于一體,經(jīng)熱分析法分析微觀組織圖驗(yàn)證,變質(zhì)前與變質(zhì)后共晶溫度相差11.5℃,變質(zhì)5~10min時(shí)硅形態(tài)呈纖維狀,變質(zhì)維持時(shí)間約1h。對(duì)鋁合金密度進(jìn)行測(cè)量,在精煉10min時(shí)密度值增大,延持至40min密度值開始降低,逐漸開始吸氣。除氣板與旋轉(zhuǎn)噴吹復(fù)合精煉的試驗(yàn)研究。通過水模擬試驗(yàn),得到除氣板精煉的最佳工藝參數(shù)是氣源壓力為0.15MPa,氣流量為0.15m3/h;除氣板與旋轉(zhuǎn)噴吹復(fù)合凈化,在氣源壓力為0.1MPa,氣流量為0.4m3/h,石墨轉(zhuǎn)子轉(zhuǎn)速為320r/min時(shí)為最佳工藝參數(shù),產(chǎn)生數(shù)量較多、分布均勻廣泛、細(xì)小彌散、尺寸較小的氣泡,沒有產(chǎn)生氣泡合并現(xiàn)象,具有較好的除氣效率。并通過實(shí)際操作進(jìn)行驗(yàn)證,經(jīng)除氣板精煉合金液的密度由2.56g/cm3提高到2.64g/cm3,顯著提高鋁熔體密度,針孔度等級(jí)從除氣前的三級(jí)變?yōu)橐患?jí),達(dá)到了較好的凈化效果。
[Abstract]:It is inevitable for aluminum and its aluminum alloy to oxidize and inhale and produce slag inclusion during the melting process, which seriously reduces the comprehensive mechanical properties and affects the final quality of castings. In this paper, a variety of complex refining technologies are studied. Through the study of the properties of inorganic salts, the compound fluxes with different functions and functions are produced. The degassing plate suitable for low pressure casting machine was developed. The method of measuring density value of aluminum alloy sample, the method of measuring needle porosity of low power microstructure of vacuum solidification sample, and the method of thermal analysis solidification cooling curve were developed. Metallographic microstructure observation method. The purification effect of compound refining technology was evaluated and judged. The results show that based on the rotary injection refining and the self-developed high efficiency slag cleaning agent, the densification of aluminum alloy is increased, the needle porosity is increased to the first order, and the densification is improved obviously from the point of view of purifying effect. The slag production is less, and the purification effect is better than that of single rotary jet refining. The modified binary fluxes have a better metamorphic effect, and the difference of eutectic temperature before and after modification can reach 5.3 鈩，

本文編號(hào)：1402333