Fabrication and Microstructure Characterization of in situ formed ZrB2 and TiB2 particles on AA6061 metal matrix composites
- In-situ fabrication of aluminum matrix composites (AMCs) has gathered widespread attention of researchers due to inherent advantages over ex-situ methods. Aluminum alloy AA6061 reinforced with various amounts (0, 2, 4 and 6 wt. %) of ZrB2 and TiB2 particles were prepared by the in-situ reaction of inorganic salts such as K2ZrF6, K2TiF6 and KBF4 to molten aluminum. X-ray diffraction patterns of the prepared AMCs clearly revealed the formation of ZrB2 and TiB2 particles without the presence of any other intermetallic compounds. The in-situ formed ZrB2 and TiB2 particles significantly refined the microstructure and enhanced the mechanical properties of AA6061 alloy. The weight percentage of ZrB2 and TiB2 was varied from 0 to 9 in steps of 3.The microstructures of the in-situ AMC were studied using Scanning Electron Microscope (SEM) andoptical microscopy. The form ation of ZrB2 and TiB2 particles in the matrix enhanced the microhardness and ultimate tensile strength of the AMCs.