Tribology characteristics of magnesium alloy AZ31B and its composites. (February 2015)

• Record Type: Journal Article
• Authors: Nguyen, Q.B.; Sim, Y.H.M.; Gupta, M.; Lim, C.Y.H.
• Is Part Of: Tribology international. Volume 82:Part B(2015)
• Page Start: 464
• Page End: 471
• Publication Date: 2015-02
• Subjects: Sliding wear -- Metal–matrix composite -- Electron microscopy -- Wear testing; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2014.02.024
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: In this paper, wear characteristics of magnesium alloy, AZ31B, and its nano-composites, AZ31B/nano-Al2 O3, processed by the disintegrated melt deposition technique are investigated. The experiments were carried out using a pin-on-disk configuration against a steel disk counterface under different sliding speeds of 1, 3, 5, 7 and 10 m/s for 10 N normal load, and 1, 3 and 5 m/s for 30 N normal load. The worn samples and wear debris were then examined under a field emission scanning electron microscopy equipped with an energy dispersive spectrometer to reveal its wear features. The wear test results show that the wear rates of the composites are gradually reduced over the sliding speed range for both normal loads. The composite wear rates are higher than that of the alloy at low speeds and lower when sliding speed further increased. The coefficient of friction results of both the alloy and composites are in the range of 0.25–0.45 and reaches minimums at 5 m/s under 10 N and 3 m/s under 30 N load. Microstructural characterization results established different dominant mechanisms at different sliding speeds, namely, abrasion, delamination, oxidation, adhesion and thermal softening and melting. An experimental wear map was then constructed. Highlights: Dry sliding wear tests were carried out on monolithic AZ31B Mg alloy and its composites. The composites exhibited superior wear resistance at high sliding speeds and loads. Coefficient of friction of composites and alloy were in the range of 0.25–0.45. Mechanisms were abrasion, oxidation, adhesion, and thermal softening and melting.