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模型合金中有序伽马相的相分离现象。经均化和两级时效后，显微组织中含有嵌入固溶体中的伽马相。在随后的老化过程中，新粒子出现在伽马相中。提出要阐明伽马相中粒子析出的机制。因此，三维原子探头(3D-AP)将跟随伽马相分解的化学发展。用透射电子显微镜(TEM)跟踪显微组织演变。研究了蠕变前后颗粒对Ni-8.5Al-5.4Ti模型合金组织稳定性的影响。结果将根据已有的蠕变变形后相稳定性的知识进行讨论。最终将验证这种相分离现象在SC16技术合金上的可转移性，从而得出相分离现象在这类合金应用领域中的应用结论。

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.