New Applications of the SPD Concept: μSPD

Abstract

Extreme grain refinement by severe plastic deformation (SPD) is an established processing approach broadly applied to bulk materials. The dimensions of specimens or workpieces used are typically in the centimeter range. We propose to adopt an analogue of equal channel angular pressing in the context of microforming. It is suggested that using sub-millimeter sized channels (“angular vias”) in a process similar to conventional forcefill technique, fibres or wires with ultrafine grain size can be manufactured. The cross-sectional dimensions of the channels can be in the micrometer range. An alternative technique that may lead to ultrafine grained fibres or wires is pressing of metals through porous “filters” with micrometer or submicrometer scale open porosity. First results demonstrate the viability of this approach which we refer to as μSPD.