Influence of grain size and grain boundaries on the thermal and mechanical behavior of 70/30 brass under electrically-assisted deformation

Decoupling Thermal and Electrical Effect in an Electrically Assisted Uniaxial Tensile Test Using Finite Element Analysis

“…As mentioned in Section II, the numerical analysis was stopped at around uniform elongation due to the validity of the input material model. Beyond localized necking, the plastic deformation is concentrated on the local zone leading to very high temperature, [14] high enough to cause recrystallization and grain growth. [16] As the deformation progressed, the average temperature in the insulated grip region was observed to increase due to lesser heat transfer to the surroundings.…”

“…[23] Yan and Conrad [22] argued that the difference in the mechanical behavior of TiAl between an external electric field and electropulsing could possibly be due to the influence of electrical pulses on the stacking fault energy, twin boundary energy, or antiphase boundary energy leading to changes in dislocation structure and twin density. Finer grains exhibited higher stress drop due to electric current than the coarse grain structure in 70/30 brass alloys [14] and pure Cu, [24] suggesting that the electric current aids the ease of dislocation motion past grain boundaries. Microstructural changes similar to annealing were observed when DC current was passed during the deformation of aluminum alloys.…”

“…[8,9] Detailed experimental investigations on the effect of material, pre-strain, polarity, and other mechanical behavior like fatigue and creep on electroplasticity have been studied on different metals in the past; details of which are summarized in the excellent reviews. [9,10] The interest in electroplasticity has gained much interest of late [11][12][13][14][15][16] in the potential application of enhancing formability [7] and reducing spring-back [17] in sheet metal components. The application is especially useful in materials such as magnesium, [18] titanium, [19] and certain aluminum alloys, [15] which exhibit poor formability at room temperature.…”

“…[14,[22][23][24] New nanophases were observed to form when coarse grained Cu-Zn alloys were subjected to electropulsing. [23] Yan and Conrad [22] argued that the difference in the mechanical behavior of TiAl between an external electric field and electropulsing could possibly be due to the influence of electrical pulses on the stacking fault energy, twin boundary energy, or antiphase boundary energy leading to changes in dislocation structure and twin density.…”

“…[8,16] One possible reason could be due to the non-homogenous temperature distribution in the lattice near dislocations. [12] The other possible explanation could be due to the localized heating at the grain boundaries under electric current; Fan et al [14] observed grain boundary melting and intergranular cavitation in brass alloys under electric current when the average temperature is much lower than that of melting. The grain size was observed to be unaffected in aluminum alloys subjected to DC pulses.…”