Grain refinement and high strain rate superplasticity in alumunium 2024 alloy processed by high-pressure torsion

Review: achieving superplastic properties in ultrafine-grained materials at high temperatures

“…10 for (a) a series of UFG Al alloys after [93] ECAP [45, 47-50, 52, 54-57] and HPT [58][59][60][61][62][63][64][65][66] and (b) a series of Mg alloys after ECAP [94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109] and HPT [110][111][112][113], respectively. For better visualization, the datum points for the samples processed by the two different techniques are illustrated in Fig.…”

“…The approach of constructing deformation mechanism maps was demonstrated for UFG Zn-22 % Al after ECAP and testing at 473 K and after HPT and testing at 473 K [115] and UFG Pb-62 % Sn after ECAP and testing at 413 K [116] and at 423 K [117]. [58][59][60][61][62][63][64][65][66] and b various superplastic Mg alloys processed by ECAP [94][95][96][97][98][99][100][101][102][103][104][105][106][107][108][109] and HPT [110][111][112][113]: the solid line shows the theoretical prediction for superplastic flow in conventional metals not processed using SPD techniques [20]. The black datum points and red datum points are for samples processed by ECAP and HPT, respectively, and they are encircled by different colors of blue for ECAP and pink for HPT It is important to mention that several recent reports demonstrated experimental evidence of enhanced atomic diffusion in nanostructured materials processed by ECAP [118,119] and HPT [120,121].…”

“…4 and 5 show the experimental data available for a series of aluminum alloys in the form of the elongation to failure and the flow stress versus the strain rate for materials processed by ECAP [46] and HPT, respectively. In practice, these plots are constructed for Al alloys showing true superplastic elongations of more than 400 % over a limited range of strain rate and with full details of the associated flow stresses in tensile testing after ECAP [45, 47-57] and HPT [58][59][60][61][62][63][64][65][66]. It should be noted that a recent report described excellent superplastic elongations including a maximum of 4100 % at 5.6 9 10 -2 s -1 in an Al-Mg-Sc-Zr alloy after ECAP [67] but no datum points for this alloy are included in Fig.…”

A Review of Transmission Electron Microscopy of Quasicrystals—How Are Atoms Arranged?

“…Since the first instrument was built in the UK in 1936 [18], TEM has revolutionized our understanding of materials: it provides the structural, phase, crystallographic and compositional information [19][20][21], which has already reached atomic scale nowadays [22,23]. In addition, the capabilities of the TEM can be further extended by adding certain detectors, such as an annular dark field detector and energy dispersive X-ray spectrometry (EDX) detector.…”

A Comparative Study on Tensile and Fracture Behavior of Al–Mg Alloy Processed Through Cryorolling and Cryo Groove Rolling

“…Severe plastic deformation (SPD) is one of the novel thermo-mechanical processing techniques used for producing ultrafine grain microstructure (UFG) with superior mechanical properties in ferrous and non-ferrous alloy [2]. SPD techniques such as Accumulative roll bonding (ARB) [3][4][5][6][7][8][9], Equal channel angular pressing (ECAP) [10][11][12][13][14][15][16], Multi-axial forging (MAF) [17][18][19][20][21], Repetitive corrugation and straightening (RCS) [22][23][24][25][26][27], High-pressure torsion (HPT) [28][29][30][31][32][33][34], are routinely used for producing ultrafine grain materials; however, the limitations associated with these techniques for largescale products are due to requirement of severe plastic strain of the order of 5 or 6 at ambient or elevated temperatures, expensive tooling, and design difficulties. Hence, they are confined to mainly for producing smalllength scale products.…”