Serration, deformation band, and strain marking in a 5083 aluminum alloy at 318K and related tempereture dependencies

Abstract

Stress fluctuation, deformation band, and strain marking in a tensile deformed 5083 aluminum alloy plate at 318K were examined using an Instron tensile machine, a stylus surface profiler, and strain gauges; related temperature dependencies were also investigated. A saw-tooth stress fluctuation was generated in the nominal stress vs. nominal strain curves in two different deformation regions, a yield point region and a region advanced by plastic deformation. A surface profiler revealed that an intermittent formation of the deformation band, known as a parallel band, resulted in both a saw-tooth-like stress fluctuation and a stair-like strain increase. The temperature dependencies of stress fluctuation, deformation band, and strain marking indicated that changes from a wavy stress fluctuation to a saw-tooth-like one with increasing deformation temperature were due to a variation in the propagation velocity and a repetition of the intermittent formation of the deformation band.