高压扭转诱导Ni_3Al合金纳米晶形成的热力学分析

Thermodynamics of Nanocrystilline Formation in Ni3Al alloy by High-pressure Torsion

以Prigogine的非平衡热力学理论、Kirchhoff定律和Miedema的热力学理论为基础,建立了Ni3Al合金高压扭转诱导纳米晶形成的热力学模型,并采用此模型计算了Ni3Al合金形成纳米晶的自由能变化,Ni3Al合金形成纳米晶的自由能变化至少增加至0.062 8 kJ.mol-1,合金从普通的粗晶结构转变为纳米晶结构。

Some researchers have got nanostructured grains in different metals and alloys by high-pressure torsion. In the present paper, a thermodynamic model was proposed based on Pringogine＇s nonequilibrium thermodynamics, Kirchhoff＇s theory and Miedema＇s thermodynamic theory, which can be used to describe that severe plastic deformation induced the formation of nanocrystalline in Ni3Al alloy. The difference of Gibbs free energy of nanocrystalline formation was calculated by this model. It was concluded that the difference of Gibbs free energy should be at least increased 0.062 8 kJ.mol^-1 in the alloy system, compared to the previous Gibbs energy before the treatment.