ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
An Al–0.5 Mg alloy and a commercial AA5182 alloy were subjected to high pressure torsion(HPT) to five turns under pressure of 6 GPa at room temperature. The grain boundary structure anddeformation defects were investigated after HPT using high-resolution transmission electron microscopy(HRTEM). Low-angle, high-angle, equilibrium and non-equilibrium grain/subgrain boundaries, twinboundaries, full dislocations, dipoles, microtwins and stacking faults were identified by HRTEM. Extrinsic 60°dislocations in the form of dipoles were frequently observed in non-equilibrium grain/subgrain boundaries. Inaddition subgrain size distributions and dislocation densities were quantified by x-ray line profile analysis. Itwas observed that the average grain size decreased from about 120 nm to 55 nm as the Mg content increasedfrom 0.5 to 4.1 wt%. Concomitantly the average stored dislocation density increased from 1.7 to 12.8 1014m-2. Based on the HRTEM investigations and the x-ray line profile analyses, the deformation mechanismassociated with the typical grain boundaries and deformation defects in the aluminium alloys were discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.584-586.528.pdf
