Development of in-situ AI-TiB2 metal matrix composites

Abstract

In-situ AI-5% TiB2 metal matrix composites (MMC) have been) successfully developed by melting together the AI-3.45%Ti and AI-l.55%B master alloys at 1000Ge for 60 min. The AI-3.45%Ti and AI-1.55%B master alloys are prepared separately by the reaction of molten Al with K2TiF6and KBF4'salts, respectively, at 800GCfor 60 min. The micro structural features of the MMCs thus prepared have been characterized by optical microscopy. XRD, SEM and EDS x-ray microanalysis with particular reference to the reinforcing TiB2particles. The study revealed that reaction of molten AI with the mixed K2TiF6 and KBF4 salts results in extensive formation of AI)Ti with very small fraction of TiB2 particles. However, melting together of the AI-Ti and AI-B master alloys at lOOOGC for 60 min resulted in the formation of AI-5%TiB2composite with the TiB2 particles of an average size of 10 microns.