Влияние внешних воздействий на ползучесть алюминиевых сплавов с микроскопическими включениями при комнатных температурах

Abstract

It is devoted to the experimental study of the creep of an aluminum alloy containing microscopic inclusions. It was found that preliminary electric ignition (j<3· 106 A/m2) of the material leads to an increase in the creep of the samples. The reasons for the observed changes are associated by the authors with the formation of local areas of high mechanical stresses near the interface of the inclusion - matrix interface. The assessment of the level of emerging local thermoelastic stresses in aluminum deltaT ~ 35 MPa, as well as the characteristic size of such areas (~ 2 µm). The observed increase in creep is determined by the resultant effect of residual stresses and stresses of thermal nature, which contributes to the creation of additional local sources of deformation in the interfacial regions. Local stress concentrators lead to a local increase in the number of mobile dislocations, which is the main reason for the change in the mechanical properties of the aluminum alloy under consideration with microscopic inclusions.