Microstructure and mechanical properties of Pb-4%Sb alloy processed by equal channel angular pressing

Abstract

Equal Channel Angular Pressing (ECAP) is the most prominent SPD (Severe Plastic Deformation) method for the production of ultrafine and nanostructured metals, and has been extensively employed and analyzed. This technique was applied to a Pb-4%Sb alloy at room temperature, in order to study its effect on a low melting point and multiphase metallic material. The material was subjected to effective strains higher than 9, after 8 passes of processing, where dynamic and static recrystallization are expected during and after each pass. This eliminates any grain refinement and allows the analysis only of the microstructural effects associated with second phase redistribution and eventual precipitate dissolution. ECAP followed route C, which eliminates structural alignment after each even ECAP pass, facilitating the study of the microstructural evolution. It is shown that three ECAP passes are necessary to completely break the lamellar structure of the as cast strucure and that antimony dissolves into the lead rich matrix. Dynamic recrystallization and structural changes reduce the material strength and change the flow curve format.

T-shaped equi-channel angular pressing of Pb–Sn eutectic and its tensile properties

“…Subsequently, there appears less effect of the number of passes on the decrease in hardness, which could be ascribed to a sluggish change in microstructure. The nature of the variation in hardness as a function of number of passes is consistent with an earlier report on Pb-4% Sb alloy subjected to L-shaped equi-channel angular pressing [20]. A similar trend was reported in a eutectic Zn-5% Al alloy, where the decrease in hardness with increasing number of passes was attributed to the softening effect [21].…”

Structure and Properties of Az31 Magnesium Alloy After Combination of Hot Extrusion and Ecap

“…The Equal Channel Angular Pressing (ECAP) method is based on the dislocation activities and is configuration during increased deformation degree [3][4][5][15][16][17][18][19]. In Fig.…”

“…It should be mentioned that, for high-angle grain boundaries (HAGBs), it may not be the case that dislocations traverse grain boundaries during deformation, rather, dislocations tend to "pileup" at grain boundaries. These pile-ups introduce stress concentrations ahead of their slip planes, which generate new dislocations in adjacent grains [3][4]. Low-angle grain boundaries (LAGBs) are not effective in interfering with the slip process because of the slight crystallographic misalignment across the boundary.…”

Influence of Severe Plastic Deformation on Mechanical Properties and Structure of Aluminium Alloys

“…where are: For creation of a very fine-grained structure formed by equiaxed grains separated by highangle boundaries the angle of ϕ = 90° and the deformation rout Bc [3] when the extruded sample after separate pass is always rotated about longitudinal axis by 90° in the direction of clock hands, is the best. Using of deformation route Bc (Fig.…”