Acoustic nonlinearity of the planar slip in the Cu-Zn alloy subjected to low-cycle fatigue

The objective of this study is to investigate experimentally the cyclic deformation in a planar slip material using acoustic nonlinearity. Observation and characterization of the dislocation substructure are conducted using an electron microscope. The acoustic nonlinearity was obtained by a superharmonic generation technique for different levels of fatigue-damaged specimens. The microstructural effects on nonlinearity are discussed in terms of the extent of planar array dislocations in the substructures after the low-cycle fatigue. The acoustic nonlinearity of Cu-Zn alloy increased with the number of fatigue cycles due to the evolution of dislocation substructures. Consequently, acoustic nonlinearity could be a potential index to characterize cyclic deformation with respect to dislocation substructures.