Cu-Al合金内氧化的热力学分析——Ⅰ热力学函数

对Cu-Al合金内氧化的热力学条件进行了分析，绘制了内氧化的热力学条件区位图。结果表明：区位图中择优氧化区位很大，范围由上、下限氧分压确定，其中：lgPO2(max)=(-1761l／T) 12．91,lgPO2(min)=(-55830／T)-(4／3)Ig％Al] 19．95，但实际的内氧化区位是靠近上限PO2，的1个很小区域；溶度积Ksp和残余Al浓度都是极小量，内氧化可进行得很彻底；内氧化控制中温度和氧分压的调节必须同步；理想的内氧化工艺条件应是：采用1223K左右的高温，介质中的氧分压力求接近或等于上限PO2；为了避免氧化，降温过程宜采用通H2急冷的方法。

Thermodynamic Analysis of Internal Oxidation of Cu-Al Alloy

Thermodynamic requirements of internal oxidation of Cu-Al alloy were systematically analyzed, and the area chart of internal oxidation thermodynamics was drawn at the same time. Results indicate that the preferential oxidation area is quite large in the area chart, which is determined by the maximum and minimum partial pressure of oxygen, where =(max)O2lgP(17 611/T)+12.91, =(min)O2lgP (55 830/T)(4/3)lg%Al]+19.95. But the practical internal oxidation area is a small part of the preferential oxidation area below the maximum partial pressure of oxygen. The volume concentration product spKand concentration of residual aluminum are such extreme minimum values that the internal oxidation can be proceeded completely. Temperature and partial pressure of oxygen should be adjusted synchronously during the control of internal oxidation. The optimum technology of internal oxidation is the adoption of high temperature of about 1 223 K, and high partial pressure of oxygen that should approach to or even be equal to the upper limit of oxygen partial pressure. Cold snap in hydrogen should be used to prevent the oxidation of copper during cooling.