Grain Refinement of Al<sub>3</sub>Ti Dispersed Aluminum Matrix Composites by Reaction Centrifugal Mixed-Powder Method

Aluminum matrix composites having dispersoids of Al3Ti intermetallic compounds can be obtained by reaction centrifugal mixed-powder (RCMP) method. It is reported that Al3Ti intermetallic compounds act as grain refiners, since the disregistry value between Al3Ti intermetallic compound phase and Al matrix is smaller than 10%. In terms of lattice registry between Al matrix and Al3Ti phase, it is expected that the grain structure of Al matrix in Al-Al3Ti composites becomes more refined than that of centrifugally cast pure Al. In this study, Al-Al3Ti composites have been cast by the RCMP method. Effects of the Al3Ti phases around Ti particles formed by reaction between Al and Ti particles during RCMP method on grain refinement behavior of Al matrix have been systematically investigated. Moreover, grain refining performance of Al cast by Al-Ti refiner with grain shaped Ti particles was also studied.