The Role of Interfacial Structure in the Evolution of Precipitate Morphology

本研究探讨成核和生长的 通过壁架机制的概念沉淀出来。 的 面心立方/体上生长壁架的形成速率- 中心立方相界面的小面沉淀物是 用热台透射法在镍铬合金中测量 电镜礁形成率预测， 经典的成核理论进行了比较， 实验性的 溶质过饱和度的贡献， 应变能和界面能对台阶形核的影响 被评估。 界面失配位错的作用 在生长过程中的沉淀物/基质边界被确定。 这些 结果应该提供几何之间的联系 解释沉淀物形状的方法， 不变线模型与析出的物理机制 增长

This investigation explores nucleation and growth of precipitates through the concept of ledge mechanisms. The formation rate of growth ledges on the face-centered cubic/body- centered cubic interphase boundaries of facetted precipitates is measured in nickel-chromium alloys by hot stage transmission electron microscopy. Ledge formation rates predicted from classical nucleation theory are compared to those measured experimentally. The contributions of solute supersaturation, strain energy, and interphase boundary energy to ledge nucleation are assessed. The role of misfit dislocations at interphase precipitate/matrix boundaries during growth is determined. These results should provide a connection between the geometric approach to explaining precipitate shape employed by the invariant line model and the physical mechanism of precipitate growth.