Achieving superplastic properties in a Pb–Sn eutectic alloy processed by equal-channel angular pressing

Developing Superplasticity in Ultrafine-Grained Metals

“…The former alloy was tested at 413 K and 10 −3 s −1 and the latter alloy was tested at 423 K and 10 −4 −10 −1 s −1 . Although the rened grain sizes were dierent in these alloys due to differences in the initial microstructures and the processing conditions, both alloys demonstrated excellent superplasticity where the former alloy achieved a maximum elongation of ≈3060% after 16 passes when testing at 413 K [79] and the latter alloy achieved a maximum elongation of 2665% at 10 −3 s −1 after 2 and 4 passes when testing at 423 K [80]. Accordingly, deformation mechanism maps of d/b against σ/G were constructed for both PbSn alloys at xed testing temperatures and these are shown in Fig.…”

“…The rst attempt at constructing maps to evaluate high temperature ow after SPD processing was performed on Pb62% Sn eutectic alloys processed by ECAP at room temperature through route B C for 4, 8 and 16 passes [79] and through route A for up to 5 passes [80] where route A denotes processing without rotation of the billet between each pass [69]. The former alloy was tested at 413 K and 10 −3 s −1 and the latter alloy was tested at 423 K and 10 −4 −10 −1 s −1 .…”

“…Accordingly, deformation mechanism maps of d/b against σ/G were constructed for both PbSn alloys at xed testing temperatures and these are shown in Fig. 8 for (a) 413 K [79] and (b) 423 K [80]. For both maps, the experimental points are shown on the maps with information of the numbers of ECAP passes and grain sizes.…”

“…8. Deformation mechanism maps of normalized grain size versus normalized stress for the Pb62% Sn alloy after ECAP under dierent conditions and testing at (a) 413 K [79] and (b) 423 K [80] showing the dominant ow mechanisms: the dashed line denotes the limiting condition for the formation of subgrains within the grains. 7.…”

Severe plastic deformation by equal channel angular pressing: product quality and operational details

“…The great majority of articles dealing with SPD are on microstructural evolution and grain size reduction mechanisms [3][4][5] , mechanical properties 6,7 , functional properties, such as superplasticity and hydrogen storage [8][9][10] , deformation and annealing textures 11,12 , and ductilization mechanisms [13][14][15][16] . This last topic is being intensively studied, since the high strength produced by the hyperdeformation reduces the work hardening rate and consequently leads to low ductility 17 .…”