(1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱150001；
2. 中國科學(xué)院 金屬研究所，沈陽 110016)
摘 要: 通過分析旋轉(zhuǎn)噴吹除氣過程中氫在惰性氣泡表面和金屬熔體/空氣界面的質(zhì)量傳輸，建立適用于鎂合金旋轉(zhuǎn)噴吹除氣的理論模型。通過計算，分析工藝參數(shù)對除氣效率的影響。結(jié)果表明：隨著旋轉(zhuǎn)噴吹轉(zhuǎn)速由230 r/min增大到330 r/min時，熔體中氣泡總表面積由1.49×10−2 m2增大到3.44×10−2 m2，這增大了熔體中氫向氣泡的單位時間擴散量，從而使除氣效率隨著轉(zhuǎn)速的增加而增大。利用減壓凝固方法對旋轉(zhuǎn)噴吹除氣的效果進行實驗驗證，實驗結(jié)果與理論模型計算結(jié)果吻合較好。該模型可以用來指導(dǎo)鎂合金熔體除氣工藝的優(yōu)化。
關(guān)鍵字: AZ91鎂合金；旋轉(zhuǎn)噴吹；除氣；熔體凈化
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Institute of Metal Research Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:A theoretical model was established for the degassing of magnesium alloy by a spinning spray based on the analysis of the mass transformation of hydrogen at the surfaces of Ar gas bubbles and the interface between the melt and air. The effect of the process parameters, such as the rotation speed on the degassing efficiency was calculated and analyzed. The results show that the total surface area of the gas bubbles increases with increasing rotation speed of spinning, i.e. the total surface area increase from 1.49×10−2 m2 to 3.44×10−2 m2 with increasing rotation speed from 230 r/min to 330 r/min. As a result, the diffusion content of hydrogen increases with rotation speed increasing, and the degassing efficiency increases. Verification experiment was conducted by measuring the density of the samples solidified under a reduced pressure. The theoretical predication is in good agreement with the experimental results, suggesting that the model could be used for the optimization of degassing processes of magnesium alloy.
Key words: AZ91 magnesium alloy; spinning spraying; degassing; melt purification
