Microstructure and microhardness of an Al-6061 metal matrix composite processed by high-pressure torsion
- Department of Mechanical Engineering, College of Engineering & Petroleum, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait)
- Department of Manufacturing Engineering, College of Technological Studies, P.A.A.E.T., P.O. Box 42325, Shuwaikh 70654 (Kuwait)
- Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom)
Disks of an Al-6061 metal matrix composite, reinforced with 10 vol.% Al{sub 2}O{sub 3} particles, were processed by high-pressure torsion (HPT) at room temperature for 1/4, 1/2, 1, 5 and 10 turns under an applied pressure of 6.0 GPa. The evolution of microstructure was investigated using optical microscopy and scanning electron microscopy. During HPT processing the average grain size within the aluminum matrix decreased from ∼ 35 μm in the unprocessed condition to ∼ 170 nm after processing through 10 turns but there was no significant effect on the size and distribution of the alumina particulate clusters. The values of the Vickers microhardness were recorded across the surface of each disk and then plotted as two-dimensional and three-dimensional color-coded contour maps. The results show the hardness increases from ∼ 56 Hv in the initial condition to ∼ 165 Hv after HPT for 10 turns. The results demonstrate that, as in many unreinforced metallic alloys, the evolution of hardness with strain exhibits strain hardening without any significant recovery. - Highlights: •The average grain size of the Al matrix was ~ 170 nm after processing for 10 turns. •No significant effect of HPT on the size and distribution of the Al{sub 2}O{sub 3} particles. •The evolution of microhardness demonstrates strain hardening without recovery. •The microhardness at low strains increases linearly from the center to the edge. •The microhardness at high strains becomes homogeneous with a saturation of ~ 170 Hv.
- OSTI ID:
- 22689583
- Journal Information:
- Materials Characterization, Vol. 118; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
Similar Records
Strengthening of Cu–Ni–Si alloy using high-pressure torsion and aging
Analysis of heterogeneities in strain and microstructure in aluminum alloy and magnesium processed by high-pressure torsion
Related Subjects
ALUMINIUM
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
GRAIN REFINEMENT
GRAIN SIZE
MATRICES
MICROHARDNESS
OPTICAL MICROSCOPY
PARTICULATES
SATURATION
SCANNING ELECTRON MICROSCOPY
STRAIN HARDENING
STRAINS
SURFACES
TEMPERATURE RANGE 0273-0400 K
THREE-DIMENSIONAL CALCULATIONS
TORSION
TWO-DIMENSIONAL CALCULATIONS
VICKERS HARDNESS