Wear Resistance and Tribological Features of Ultra-Fine-Grained Al-Mg Alloys Processed by Constrained Groove Pressing-Cross Route

Journal Article · Fri Feb 15 04:00:00 EST 2019 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-019-3859-3· OSTI ID:22970949

Mozafari, J. ^[1]; Eskandari, H. ^[1]; Haghshenas, M. ^[2]

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1. Persian Gulf University, Department of Mechanical Engineering (Iran, Islamic Republic of)
2. University of North Dakota, Department of Mechanical Engineering (United States)

In the present study, the wear behavior of ultra-fine grained (UFG) Al-Mg alloys produced by a severe plastic deformation (SPD) method was assessed and compared against the annealed coarse-grained alloy. To this end, weight loss, wear resistance, friction coefficient, and morphology of the worn surfaces was investigated. Constrained groove pressing-cross route (CGP-CR) process, an SPD technique, was implemented at ambient temperature up to two passes to impose an equivalent plastic strain of about 4.64. Formation of a UFG structure with an average sub-grain size of ~ 350 nm with an enhanced tensile strength of up to ~ 225 MPa and indentation hardness of up to ~ 95 HV were achieved upon two passes of CGP-CR process. The pin-on-disk dry wear sliding testing was conducted up to a distance of 1000 m under normal loads of 5, 7, and 9 N at a constant sliding speed of 0.5 m/s. The trends measured for the evaluation of wear properties/mechanisms are discussed based on the microstructural features and mechanical property of UFGed alloys. The results showed that by employing the CGP-CR process and through the formation of UFG structure, the wear resistance was considerably increased. This was even beyond two times (~ 100%) larger depending on the normal loading with the lowest coefficient of friction around 0.6. Observation and study of the morphology of the worn surfaces under field emission-scanning electron microscopy (FE-SEM) revealed a change in the wear mechanism from sticking followed by formation of plastic deformation bands and delamination in the coarse-grained annealed alloy into a combined abrasive-adhesive behavior in the UFG material.

• OSTI ID: 22970949
• Journal Information: Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 2 Vol. 28; ISSN 1059-9495; ISSN JMEPEG
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AMBIENT TEMPERATURE
CHROMIUM ALLOYS
FRICTION FACTOR
GRAIN SIZE
IRON ALLOYS
PLASTICITY
PLASTICS
SCANNING ELECTRON MICROSCOPY
SELENIUM ALLOYS
TENSILE PROPERTIES
WEAR RESISTANCE