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

点击翻译按钮获取中文摘要

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.