High-pressure torsion of thick Cu and Al–Mg–Sc ring samples

Abstract

Pure Cu and an Al-3 %Mg-0.2 %Sc alloy are processed by high-pressure torsion with ring-shape samples having an initial thickness of 4 mm. Microstructural observation across the thickness is carried out using optical microscopy and transmission electron microscopy to correlate with hardness variation. It is shown that the strain is introduced more intensely in the center of thickness on the cross sections for both pure Cu and the Al alloy. This area expands with an increasing number of revolutions but the expansion saturates before covering the entire cross section. Softening occurs with straining in pure Cu but saturation reaches without softening in the Al alloy. It is suggested that imposed strain is estimated using the thickness of severely deformed region.

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.…”