Investigation of deformation mechanisms in an advanced FeCrAl alloy using in-situ SEM-EBSD testing

The deformation mechanisms associated with uniaxial tensile testing are studied by conducting tensile experiments of an FeCrAl alloy using scanning electron microscopy (SEM) coupled with electron backscattered diffraction (EBSD). Prior to the deformation, investigated alloy was consisting grain and precipitate size of-63.0 mu m and-6.7 mu m, respectively. The recorded SEM micrographs and EBSD data at increasing levels of strains revealed the complex phenomena of slip bands' formation in the presence of surface grain morphology evolution and their (001), (110) and (111) crystallographic planes distortions. The grains with orientation (110)||tensile direction (TD) shows higher shape change; however, (001)||TD and (111)||TD oriented grains show higher lattice gradient formation. Extracted information from the EBSD indicates that the crystallographic rotations drive towards specific, fiber-like texture in relation to the loading direction. Postmortem analysis of the recorded microstructure during the tensile deformation explains the phenomena of crack formation in the hardintermetallic particles before the ultimate tensile strength (UTS). However, after the UTS, pores were identified in the neck that resulted from extensive plastic deformation. In-depth analysis was carried out to identify the cause of cracks and pores formation phenomena during the tensile test.

Automated summary

The deformation mechanisms associated with uniaxial tensile testing were studied using scanning electron microscopy (SEM) coupled with electron backscattered diffraction (EBSD) on an FeCrAl alloy. The experiments revealed complex phenomena such as slip bands' formation, surface grain morphology evolution, and crystallographic planes distortions. The grains' orientation and crystallographic rotations were found to influence the shape change and lattice gradient formation. Postmortem analysis explained the crack formation in the hard intermetallic particles and the formation of pores after the ultimate tensile strength (UTS).