In this research, feasibility of producing A356/CNT nanocomposite open-cell foam via melt squeezing technique was investigated. Open-cell aluminum foams have gained some significant applications in various industries because of their specific structural and mechanical characteristics. Success in producing CNT-incorporated open-cell aluminum alloy foams based on casting approach can ascertain their usage in more critical applications and also their mass-production. To achieve this goal, this project was conducted in three sections. At the first section, the influential parameters for production of open-cell A356 aluminum alloy foams via the melt squeezing procedure was optimized and effects of foam making variables on mechanical properties of the resultant foams were assessed. The influence of cell size and piston pressure on the porosity and mechanical properies of final foams was also simulated using artificial neural network (ANN). At the second section, various techniques for producing aluminum alloy-based nanocomposites containing different CNT weight percentages were utilized and the optimal one was selected. Finally, the possibility of producing aluminum-based nanocomposite foam using the optimal parameters of the two preceding stages was investigated. The results showed that foams comprising coarse and fine cell sizes yielded the highest strength and the highest energy absorption capacity, respectively. Production of bulk nanocomposites were only materialized by applying melt stirring speeds of more than 2000 rpm. Among variant amounts of the reinforcement incorporated into the melt, the composite containing 1 wt% CNT and 1 wt% Ti showed the best mechanical properties (including shear, bending and compressive strengths) among which the bending strength was improved by about 27% in comparison with the monolithic casting. However, due to the inconsistencies amongst the foam optimum production parameters and those of the bulk nanocomposite, production of nanocomposite foam, as the ultimate purpose of this thesis, was not feasible. The non-practicability of using high stirring speed as well as lack of rapid solidification condition in the foam making procedure, which results in CNT segregation, were recognized as the most important reasons for this failure. Key Words: Open-cell aluminum foam, A356-CNT nanocomposite, nanocomposite foam, vortex casting, mechanical properties, microstructure, artificial neural network
