Centrifugal Casting of Nano Crystalline TiB2 Reinforcement Particulate Reinforcement in Al-Alloy Matrix

Abstract

A method of producing Nano size TiB₂ particles within an aluminium matrix is the in situ reaction synthesis method, using KBF₄ and K₂TiF₆ potassium based bearing fluxes. The advantages of this in situ reactive process are a small particle size and good particle/matrix interfacial bonding. However, this method is limited to producing low particulate volume percentage material (Ë‚6 vol%). To overcome this limitation, centrifugal casting has been investigated. A series of the casts was made to observe the influence of centrifugal acceleration “G” value on final TiB₂ distribution. This was done by the casting at 1400 RPM rotational speed and 570 G value. The TiB₂ particulates content was concentrated towards the outer radius with a clear interface between this region and the remaining unreinforced Aluminium matrix. The final concentration of the TiB₂ particles increased with increase in rotational speed and particle clustering was found to influence the settling behavior of the TiB₂ particles. The present paper demonstrates that centrifugal casting may be employed to yield a 6 Vol% of TiB₂ reinforced particulate metal matrix composites.