Creep processes in pure aluminium processed by equal-channel angular pressing

Creep properties of aluminium processed by ECAP

“…In our previous works [12][13][14][15][16][17], it was found that the sample after 1 ECAP pass exhibited the highest creep resistance. This suggests that the highest creep resistance can be achieved in inhomogeneous ECAP-processed microstructure containing a high density of LAGBs but a lower density of HAGBs.…”

“…The recent results show that creep behaviour of UFG materials can be significantly influenced either by GBS [15] or by the enhanced recovery of dislocations at HAGBs [10]. Both of these mechanisms occur easily when the grain size is finer than quasi-stationary spacing of LAGBs [29,30] w qs = k wτ bG/τ = k wσ bG/σ (where τ is resolved shear stress, k wσ = Mk wτ is about 10 to 30, M = σ/τ is Taylor factor, and G is shear modulus at temperature T ).…”

“…10, 11) revealed the displacement of marker lines at grain boundaries giving the qualitative evidence relating to an activity of GBS during creep of ECAP-processed Al. Sklenička et al [15] investigated creep behaviour of UFG Al at 473 K and they concluded that contribution of GBS to the total creep strain in the UFG Al was only about 33 %. Certain quantitative data are also available for a tensile test of pure Al performed at room temperature and engineering strain rate 8.6 × 10 −3 s −1 [31].…”

“…Creep in polycrystalline materials after SPD processing was investigated on pure metals [10][11][12][13][14][15][16], alloys [17][18][19][20], and Cu-Al 2 O 3 composite [21]. However, there are a few reports documenting the creep properties and creep mechanisms of the ultrafine-grained (UFG) materials processed by different numbers of ECAP passes.…”

Structure of Ecap Aluminium After Different Number of Passes

“…In the preceding studies Ilucová et al (2004) and Sklenička et al (2006) was examined the structure of pure aluminium (99.99%) after a particular pressing process (consisting in eight passes of a rod-shape billet through the channel bent at a right angle and then, before the next pass, rotated by 90° in the same direction − so-called route B C ) and then also after the subsequent creep deformation (performed at 473K after an annealing for 4 hrs under no external load before creep testing) (Sklenička et al, 2005;2006;Saxl et al, 2007).…”