(1. 安徽工業(yè)大學(xué) 機(jī)械工程學(xué)院，馬鞍山 243002；
2. 華中科技大學(xué) 材料科學(xué)與工程學(xué)院，武漢 430074)
摘 要: 利用自行研制的鎂合金快速定量測氫儀研究通Ar除氣處理AZ91鎂合金熔液的效果，以及通Ar流量、通Ar時間和精煉溫度三因子對AZ91鎂合金熔液精煉的影響。運(yùn)用正交試驗方法獲得通Ar除氣工藝的最佳工藝參數(shù)，即通Ar流量為1.0~1.5 L/min，通Ar時間為20~25 min，鎂合金溫度為725~750 ℃。從熱力學(xué)和動力學(xué)角度對鎂合金熔液的除氣機(jī)理進(jìn)行探討，建立導(dǎo)入鎂合金熔液中Ar氣體積的熱力學(xué)關(guān)系式，并進(jìn)行動力學(xué)方面的分析。結(jié)果表明：由于實際除氫時吸入氫，在理想條件下所推導(dǎo)的除氣速率的動力學(xué)方程的理論計算值與實際數(shù)值存在較大差異。
關(guān)鍵字: 鎂合金熔液；除氫；正交試驗方法；熱力學(xué)；動力學(xué)
magnesium alloy melt
（1. School of Mechanical Engineering, Anhui University of Technology, Ma’anshan 243002, China;
2. Institute of Materials Science and Technology, Huazhong University of Science and Technology,
Wuhan 430074, China）
Abstract: Purging effects of Ar fluxing were investigated with a self-developed instrument for measuring hydrogen content in magnesium alloy melt, and the influences of three factors, namely, Ar flow rate, degassing time and temperature of magnesium alloy melt on purging effects were also studied. The optimal parameters were obtained by experiments with orthogonal experimental design that the Ar flow rate is 1.0−1.5 L/min, the degassing time is 20−25 min and the temperature of magnesium melt is 725−750 ℃. The degassing mechanism of magnesium alloy melt was analyzed according to the thermodynamic and dynamic theory. Thermodynamic equations of volume of Ar gas entering into magnesium alloy melt were established. Furthermore, the degassing dynamics was also analyzed. The experimental results show that the theoretical data of the deduced dynamic equation of degassing rate under ideal conditions are not consisted with the real values because hydrogen enters into magnesium melt with degassing under real condition.
Key words: magnesium alloy melt; degassing; orthogonal experimental method; thermodynamics; dynamics
