两种Ti—Al金属间化合物基合金ISM熔炼过程中Al元素挥发控 …

Evaluation of the Control Mode of Al Element Evaporation During ISM Process of Ti-Al Intermetallics

摘要:

对水冷铜坩埚真空感应熔炼过程中合金元素的挥发动力学进行了深入的分析，并在此基础上建立了ＩＳＭ熔炼过程中Ａｌ元素挥发控制方式的判断模型。对Ｔｉ－４８Ａｌ－２Ｃｒ－２Ｎｂ（ａｔ％）和Ｔｉ－２４Ａｌ－１１Ｎｂ（ａｔ％）合金中Ａｌ元素挥发控制方式的判断结果表明：随着熔体温度的升高和外压的增大，Ａｌ元素的挥发由低温和高压时的界面挥发控制向高温和低压时的界面挥发和液相中扩散同时起作用的双重控制方式转变，只是对

Abstract:

On the basis of an in-depth analysis of the evaporation process of alloying elements during induction skull melting (ISM) amodel for the control mode of element evaporation has been established. The calculated results of Al element evaporation in Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys show that when melt temperature increases and/or pressure decreases, the controlmode of Al element evaporation changes from an evaporating reaction control mode at low melt temperature and/or under high outerpressure to a double control mode-evaporating reaction and liquid phase diffusion at high melt temperature and/or under low pressure. When the outer pressure is 133.3 Pa, the transformation temperatures of the control mode of Al element evaporation are approximately 1950 K and 2000 K respectively for the Ti-48Al-2Cr-2Nb (at%) and Ti-24Al-11Nb (at%) alloys. While the transformation pressures of the same alloys are approximately 133. 3 Pa and 66 Pa respectively when the melt temperature is 2073 K. Thereason is that the saturated vapor pressures of Al element in various alloys are different.