The increased role of advanced materials in mechanical design optimization has purred the development of new material types and combinations previously unavailable to the designer. These new materials give the designer the ability to design higher density systems by matching the material characteristics of all parts within the system. Certain metal matrix composites now allow the designer to select needed material properties over a fairly large range for example (thermal expansion, conductivity and material strength).The current work has been made for the evaluation of coefficient of thermal expansions (CTE) of Aluminum based cast composites reinforced with mixture of (Al2O3 ) and (SiC) particles with different volume fraction. The cast composites have been prepared by liquid metallurgical route. The results show that (CTE) significantly increased with increasing temperature up to 400 C. But it has been observed that (CTE) decreases with increasing volume fraction of reinforcing particles. The (CTE) values were found to be comparable with theoretical results. Turner model showed good agreement with the current experimental results.
Key words: Coefficient of thermal expansion(CTE); Aluminium metal matrix composites ;AL2O3 and SiC particles.