The Microstructure, Hardness and XRD Analysis of in-Situ Al 6061-TiB2 Metal Matrix Composites with Different Reaction Holding Times

Aluminum Metal Matrix Composite (AMMC) is studied and extensively established for various commercial and industrial applications due to mechanical properties, low thermal expansion coefficient and low density, higher thermal and electrical behavior and better corrosion resistance. In this experimental study, Al6061-TiB2 Metal Matrix Composites prepared by stir casting and in-situ techniques by the introduction of halide saltsKBF4and K2TiF6 in the Al 6061 molten matrix at 850 °C. The reinforcement phase, TiB2 formed due to the exothermic reaction between the molten Al 6061 alloy and halide salt that is equally distributed throughout the matrix due to the combined effect of stir casting and in-situ techniques. We study the hardness, XRD analysis and microstructure of the composites with diverse reaction holding times from a minimum of 15 minutes to a maximum of 60 minutes. The XRD analysis and microstructure show the distribution of adequate TiB2 particles in the production of Al 6061-TiB2Metal Matrix composite comparable to other AMMC candidates. In the current study, it was found that 30minute's reaction holding time ensures uniform distribution and maximum hardness of the reinforcement phase, TiB2 at the matrix phase, Al 6061 alloy.