Incremental ECAP as a novel tool for producing ultrafine grained aluminium plates

Conventional equal channel angular pressing is an efficient technique to obtain bulk ultrafine grained materials (UFG) with extraordinary mechanical properties in the form of rods. In this work, an incremental method of ECAP process which allows to obtain thick sheets with UFG structure is presented. Using this method square plates (62 × 62 mm) were obtained. In this case, a combined route – A+ specific B – with 90 degree rotation along plate normal after each pass keeping other planes in the same positions relatively to the channel – has been applied. The efficiency of this methods was proved for technically pure 1050 aluminium. It was processed by incremental ECAP using 8 passes of A+B route. To characterize microstructure visible light microscopy and transmission electron microscopy were used. Mechanical properties were measured by microhardness test. The results obtained showed that the microstructure and mechanical properties of 1050 aluminium alloy processed by incremental ECAP are comparable to conventional ECAP. However, the new processing method broaden the potential applications of UFG materials.