| Hybrid metal matrix composites (HMMC's) are next generation metal matrix composite materials that have the potential of gratifying recent demands of advanced energy applications in the field of aerospace, automobile and biomedical. The MMC's have to work at elevated temperature or vacuum environment where lubrication using liquid lubricants is ineffective or difficult to achieve; moreover, liquid lubricants are not environmental friendly, since they release pollutants into environment. Solid lubricants such as graphite, CNT's, MoS2 and graphene have been widely used as secondary reinforcements to meet such operational needs by fabricating green or environmental friendly self lubricating HMMC's. This article outlines recent advances in the area of self lubricating HMMC's reinforced with graphite as secondary reinforcement. The focus of the study was on mechanical and tribological behavior of Aluminum and magnesium based self lubricating HMMC's. The effect of graphite, different hybrid reinforcements and their strengthening mechanisms are also discussed in detail. |
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