Microstructural development of adiabatic shear bands formed by ballistic impact in a WELDALITE 049 alloy

Abstract

The object of the present study is to investigate the microstructural development of the adiabatic shear band formed by ballistic impact in a WELDALITE 049 alloy. The microstructure of the shear band was examined by optical microscopy and transmission electron microscopy. The results indicated that the adiabatic shear band consisted of fine recrystallized grains with a high dislocation density. This microstructure was considered to be formed in an extremely short time by the combined effects of the highly localized shear deformation and the high-temperature rise that occurred within the shear band. However, no precipitates could be observed in the interior of the grains, since the temperature rise in the shear band formation process was inferred to be above 460 degrees C and below the solidus temperature. Dynamic recrystallization was suggested as a possible mechanism to explain the microstructural development of the adiabatic shear band formed in the WELDALITE alloy.