Investigation of the mechanical behavior of MAX phases by acoustic emission technique

Mechanical properties of two ternary carbides at room temperature were investigated under cyclic bending test with simultaneous acoustic emission monitoring (AE). Results show significant differences between both of them in terms of observed microstructural changes associated to acoustic emission response. Thanks to this technique coupled with an accurate micrographic investigation by SEM, mechanisms such as debonding of layers in MAX phases grains or damage occurrence in secondary intermetallic phases (microcracking) were identified and their specific acoustic signatures separated populations of AE signals were distinguished. In addition, bending test were also conducted at specific temperatures (1073 K and 1473 K) in order to investigate the brittle-to-ductile transition of both materials.