Dry sliding wear studies of aluminum matrix hybrid composites

摘要

In the present work, hybrid composites are fabricated with self-lubricating characteristics to make them as resource-efficient materials. AA6061-10 wt. % B₄C–MoS₂ hybrid composites reinforced with 2.5, 5 and 7.5?wt. % concentration of MoS₂ particles are produced using stir casting technique, and mechanical and tribological properties are evaluated. Microstructural characterization of the hybrid composites revealed the uniform distribution of reinforcement (B₄C and MoS₂) particles in the matrix material. Hardness and fracture toughness of the hybrid composites are decreased monotonously with an increase in the addition of MoS₂ particles. Dry sliding tribological studies conducted using a pin-on-disk tribotester under atmospheric conditions revealed the formation of MoS₂-lubricated tribolayer on the worn pin surface which significantly influenced the tribological properties. The addition of MoS₂ particles decreased the friction coefficient and wear rate of the hybrid composites. Delamination and abrasion are observed to be the controlling wear mechanisms and material in the form of platelet-shaped debris, and flow-type chip debris is formed, and a long and shallow crater on the worn pin surface of the hybrid composite is also observed.