Preparation of in-situ 5 vol% TiB2 particulate reinforced Al-4.5Cu alloy matrix composites assisted by improved mechanical stirring process

In-situ 5 vol% TiB2/Al-4.5Cu composites are successfully prepared by the salt-metal reactions assisted by improved mechanical stirring. The X-ray diffraction confirms the formation of TiB2 particles, and no cluster or large precipitate of intermediate phases Al3Ti and AlB2 can be traced. Mechanical stirring can reduce the large agglomerations and finally eliminate them when the speed rises to 540 rpm. Most of TiB2 particles are uniformly distributed along the grain boundary in the matrix, and lots of dispersed particles with a size under 0.4 mu m are also found. Yield stress and ultimate tensile strength of the composite are improved by 85% and 46%, respectively. (C) 2016 Elsevier Ltd. All rights reserved.