Tribological behaviours of hybrid Zn–Al metal matrix composites produced by a rapid current sintering technique

Abstract

Purpose

The objective of the present investigation is to prepare a Zn–Al matrix (73 wt. per cent Zn + 27 wt. per cent Al) reinforced with SiC and graphite (Gr) hybrid composites by a rapid current sintering technique. Well-known Zn-based alloys are good candidates for load bearing applications. However, some limitations exist in Zn sublimation during casting and solid-state sintering and low-sliding velocity applications. The purpose is to develop new hybrid composites for self-lubricated bearing alloys by the facile production technique of current-activated sintering for these types of hybrid composites at very short sintering periods.

Design/methodology/approach

Designing a special power unit for current sintering. The hybrid composites of the Zn–Al matrix were reinforced with 20 vol. per cent SiC and different amounts of Gr (2.5, 5.0, 7.5 and 10 weight per cent) and sintered rapidly by current sintering. Tribological tests for wear behaviors and self-lubrication effect were studied. The authors' approach is mainly to produce low-cost load-bearing materials.

Findings

Successful and rapid production of Zn–Al alloy SiC/Gr hybrid composites in this study led to increasing load bearing capacity, decreasing friction coefficient and wear rate and production of good substitutes for conventional bearing applications.

Originality/value

A conventional Zn alloy was reinforced with both SiC and Gr particles. This work is original in two ways. It is noted after the literature survey that this alloy is first reinforced with two different types of reinforcements as a hybrid type of composite. Second, the consolidation of this hybrid material was carried out by a direct current for eliminating Zn sublimation and shortening the production time. In tribological applications demanding strength and lubrication requirements, Zn–Al/SiC/Gr hybrid composites were assessed as good substitutes for conventional materials owing to improved wear resistance as a result of combined reinforcement of SiC and Gr particulates.

Citation

Karslioğlu, R., Akbulut, H., Uysal, M. and Bağdatli, G. (2014), "Tribological behaviours of hybrid Zn–Al metal matrix composites produced by a rapid current sintering technique", Industrial Lubrication and Tribology, Vol. 66 No. 3, pp. 481-489. https://doi.org/10.1108/ilt-11-2011-0091