Effect of microalloying with La and Nd on adiabatic shear behavior in ultra-coarse grained Cu alloy under quasistatic tensile loading

Generally, adiabatic shear bands (ASBs) are formed under the conditions of dynamic loading and high strain rate deformation. Recently, we have observed the formation of the ASBs in ultra-coarse grained copper (Cu) alloys under quasi-static tensile loading. Our experimental results extend the formation mechanism and conditions of the ASBs. The results show that the addition of trace La and Nd elements in pure copper can promote the randomization and diversification of deformation texture, and inhibit the dynamic recovery process. The deformation mechanism of the as-casted rare-earth modified Cu alloy mainly includes grain boundary coordination deformation, dislocation slip and adiabatic shear deformation. The strengthening mechanism of the alloy mainly involves dispersion strengthening, grain refinement strengthening and strain hardening. The ASBs are formed in the pure Cu and Cu alloys during quasi-static tensile deformation, which is mainly related to the dynamic recrystallization process and the low strain rate sensitivity of the ultra-coarse grained Cu alloys.