镍对Fe-Cu-Ni合金中铜析出行为的影响

 利用透射电子显微镜(TEM)对Fe-Cu和Fe-Cu-Ni合金中铜颗粒的析出形貌及成分进行观察。同时根据Cahn-Hilliard非经典形核理论和Modified Langer Schwartz模型对合金中沉淀的析出过程进行模拟计算。扫描透射电镜(STEM)试验结果表明，镍元素在沉淀核心处浓度很低，而在颗粒-基体界面处存在富集现象，添加元素镍可降低沉淀颗粒的形核功，促进沉淀析出和长大粗化。该试验结果与理论模型预测结果一致。

Influence of Ni on Cu Precipitation in Fe-Cu-Ni Alloy

The precipitation behaviors,including precipitates′ morphology and distribution of composition,of Cu-rich particles in Fe-Cu and Fe-Cu-Ni alloys are investigated by transmission electron microscopy(TEM).Besides,according to Cahn-Hilliard non-classical nucleation theory and Modified Langer Schwartz simulation,theoretical model is set up to simulate the precipitation process.The experimental results by means of scanning transmission electron microscopy(STEM) indicate that the composition of Ni at the core of the nucleus is comparatively low.While there is enrichment of element Ni at the precipitate/matrix interface as Cu-rich precipitates nucleate,grow and coarsen,which agrees with the anticipation of theoretical simulation.