Evaluation of strain fields caused by the η′ phase in an Al-Zn-Mg-Cu alloy

Strain fields around the η′ phase precipitated in an Al-12Zn-2.4Mg-1.1Cu alloy were quantitatively measured employing high-resolution transmission electron microscopy (HRTEM) and geometric phase analysis (GPA) technique. Afterwards, experimental strain maps were compared with the simulated strain maps obtained from a simulated HRTEM image which was created using the CrystalMaker and JEMS software. Compressive strain is found around the η′ phase, and the maximum compressive strain is about 2.8%. The simulated results are consistent with the experimental results to describe the distributions of strain fields around the η′ phase along the x direction which is parallel to [1¯1¯1 ]Al direction.