Tribological properties of Hot forged Al2024-TiB2 in-situ composite

A B S T R A C T Al2024-TiB2 in-situ composite was fabricated by liquid metallurgy route using Al-Titanium and Al-Boron master alloys. The developed composites were subjected to hot forging at a temperature of 500oC using a 200T hydraulic hammer. Microstructure studies, X-ray diffraction studies(XRD), grain size analysis, microhardness and dry friction and wear tests were carried out on as cast and hot forged matrix alloy and its composites. Pin on disc type machine was employed to perform friction and wear tests over a load range of 20-100N and sliding velocities of 0.314-1.57m/s. Microstructure and XRD studies reveal presence of fine TiB2 particles in both as cast and hot forged condition. It is observed that, both as cast and hot forged composites do exhibit significant grain refinement. When compared with as cast matrix alloy and its composite, hot forged alloy and its composite exhibits higher extent of grain refinement. Both as cast and hot forged composites exhibit improved microhardness, wear resistance and lower coefficient of friction when compared with the unreinforced alloy under identical test conditions.