HIGH-TEMPERATURE DEFORMATION OF COMMERCIAL-PURITY ALUMINUM

The stress-strain behavior of aluminum 99.5 pet (2-9) purity deformed under hot-working conditions has been found to be satisfactorily descr ibed by combining the exponential saturation equation earlier proposed by Voce and a latter model advanced by Kocks. Voce's equation describ es the strain dependence of the flow stress, whereas the temperature a nd strain rate dependencies of both the initial flow stress and the sa turation or steady-state stress are introduced by means of Kocks' mode l, which leads to the definition of a different temperature-compensate d strain rate parameter. The basic principles of the dynamic materials model (DMM) advanced by Gegel and co-workers has been reassessed, lea ding to a different proposition in relation to the calculation of both the power dissipator co-content (J) and the power dissipation efficie ncy (eta), which:makes use of the constitutive equation previously dev eloped. Such concepts are later applied to the analysis of a typical i ndustrial hot-rolling process conducted on commercial-purity aluminum. From the microstructural point of view, hot rolling of commercial-pur ity aluminum has been found to be conducted under conditions of relati vely low power dissipation efficiency (eta approximate to 0.20 to 0.25 ), which is likely to be associated with the predominance of dynamic r ecovery as the main dislocation rearrangement mechanism.