基于JMatPro软件不同B含量下Co-8.8Al-9.8W合金析出相的热力学模拟计算

Thermodynamic Simulation Calculation of Co-8.8Al-9.8W alloy with different B content based on JMatPro software

摘要:

为研究B元素对新型钴基高温合金析出相的影响，本文基于JMatPro热力学模拟计算软件对不同B含量下Co-8.8Al-9.8W合金的平衡相析出行为进行了研究。结果表明：B含量的增加，会导致γ相、μ-Co7W6相析出温度的降低，并减少γ相、μ-Co7W6相析出量，相反会提高η-Co3Al相的析出温度及析出量。针对这一计算结果，本文作者从B对平衡相中各元素的影响，硼化物等角度分析，给出了解释。分析认为随着B含量的增加，使γ相析出时固液平衡相中各元素的含量相差越来越多，要满足γ相的形核和长大只有降低温度增加过冷度来实现。从而导致随着B含量的增加，γ相的含量越来越少，析出温度越来越低。硼化物的析出，固溶了大量的Co、W，使固液平衡相中Al的含量增加，促进了Co3Al的析出。

Abstract:

In order to research the effect of boron additions on precipitation phases of New Co base superalloy. to save cost and to short period. The precipitation phases of Co-8.8Al-9.8W alloy with different B content have been studied by Thermodynamic Simulation Calculation of JMatPro software. The result shows that the precipitation temperature and precipitation quantity of γ phase and μ-Co7W6 phase becomes lower while the content of B increases. whereas the precipitation temperature and precipitation quantity of η-Co3Al phase becomes higher. Finally, the result has been explained from the factors of boride phases and the effect of B on composition of precipitation. Interpretation indicates that with the increase of B content，content of each element of Solid-liquid equilibrium phase has a growing difference when γ phase precipitates ,lowering the temperature increases, increasing the degree of super cooling, can make phase γ nucleation and growth. Thus with the increase of B content, the content of γ phase gets less and the precipitation temperature gets lower. The precipitation of borides leads a lot Co, W solid solution, which made a growth of Al in the solid-liquid equilibrium phase and promotes the precipitation of Co3Al.