The phanomenon of separation in the ordered phase of a Ni-Al-Ti model alloy

本项目旨在研究Ni-8.5Al-5.4Ti模型合金中有序γ ′相的相分离现象。经均匀化和两级时效后，显微组织中含有嵌入固溶体基体中的γ ′相。在随后的老化过程中，新的粒子出现在γ ′相中。建议澄清γ ′相中颗粒沉淀的机制。因此，将通过三维原子探针（3D-AP）跟踪γ ′相分解的化学发展。微观结构演变将通过透射电子显微镜（TEM）进行跟踪。研究了Ni-8.5Al-5.4Ti模型合金在蠕变变形前后，颗粒对合金组织稳定性的影响。将讨论的结果与蠕变变形后的相稳定性的现有知识。最后将验证这种相分离现象在工业合金SC 16上的可转移性，以得出在这种合金的应用领域中利用相分离现象的结论。

This project aims on the investigation of the phase separation phenomenon of the ordered gamma´ phase in Ni-8.5Al-5.4Ti model alloy. After homogenization and two-stage aging the microstructure contains gamma´ phase embedded in solid solution matrix. During a subsequent ageing new particles appear within the gamma´ phase. It is proposed to clarify the mechanism of particle precipitation within the gamma´ phase. Therefore, the chemical development of decomposition of the gamma´ phase will be followed by three-dimensional atom probe (3D-AP). The microstructural evolution will be followed by transmission electron microscopy (TEM). The influence of the particles on the stability of microstructure of the Ni-8.5Al-5.4Ti model alloy will be studied before and after exposure to creep deformation. The results will be discussed with respect to already existing knowledge of phase stability after creep deformation. Eventually the transferability of this phase separation phenomenon on the technical alloy SC16 will be verified to draw conclusions on the utilization of the phase separation phenomenon in the application field of such alloys.