Mechanical properties of in-situ TiB2/A356 composites

In the present work, the in-situ TiB2/A356 composites were successful synthesized through the salt-metal reaction route. The research was undertaken to study the mechanical properties of the A356 alloy reinforced with TiB2 particles at both as-cast state and T6 state. In two cases, the results showed the Young's modulus of composites was increased with increasing the TiB2 content up to 8.37% in volume fraction. The dependence of Young's modulus on the TiB2 particle content can be well rationalized by the Tsai-Halpin equation. Similarly, the yield strength of composites was improved with the increase of TiB2 particle content at both states. Using the modified shear lag model, the calculated yield strength can be well fitted with the experimental values at as-cast state, but not at T6 state. Further, a phenomenological model was proposed by accounting for TiB2 particulate strengthening mechanisms and microstructural features related coefficient in TiB2/A356 composites. The predictions of yield strength using this model are in good agreement with experimental data from both as-cast state and T6 state in this work and also reported in the literatures about in-situ TiB2/Al alloy composites. (C) 2013 Elsevier B.V. All rights reserved.