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-toothlike 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.

It is well known that a strain aging was effective technique for a prevention of a strain marking in steel materials, whereas there are few reports on aluminum alloys on this issue. In the previous study, strain aged 5083 aluminum alloy plates were tensile deformed in order to investigate the effect of strain aging temperature and time on a generation of a stress fluctuation resulted in the strain marking. The findings suggested that a generation of stress fluctuation was affected not only by the strain aging temperature and time but also by the holding stress, which was applied to a specimen during the strain aging. In the present study, therefore, the strain aging in a wide range of holding stress was carried out, and the effect of holding stress on a generation of stress fluctuation was investigated. In addition, the influence of temperature, time, and holding stress during the strain aging on a generation of stress fluctuation was discussed in detail. Experimental results showed that the stress fluctuation tended to generate with increasing the holding stress. When the specimens were strain aged at the holding stress that corresponded to the flow stress when deformation was interrupted, the stress fluctuation that had been generated in a short aging time disappeared clearly as aging time extended.