الفهرس 
. INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 96 |  |  |
| | | from | 96 | | |
Abstract
Metal foams are synthetic multi-phase materials with a stochastic three-dimensional cellular structure that simulate the structure of natural porous materials like bamboo and bones. The existence of porous phase within these materials offers exceptional physical and mechanical properties such as low density, insulation, permeability, high specific strength, high energy absorption, and damping. The immense research in this area promoted applying recently developed metal foams widely in diverse fields like catalysts, filters, heat exchangers, sound isolation, shock absorbers, sandwich panels for vehicle frames, and bio-medical implants. Metal foams are categorized according to their cellular structure into open-cell and closed-cell foams. Open-cell metal foams are considered more appealing due to their permeable structure, which allowed them to be employed in several functional as well as mechanical applications. The current research focuses on studying the process parameters affecting the physical and mechanical behavior of open-cell aluminium foams manufactured by infiltration casting (pressurized casting) technique. This technique includes pressurizing molten metal into the intercellular distances of a compacted preform composed of leachable particles. The investigated parameters include the preform compaction pressure, particle size, and gas infiltration pressure. The initial step is the design and manufacturing of an experimental setup. Afterward, the setup validation is carried out through preliminary experiments that are also meant to establish and optimize the process parameters. To investigate the significance of each parameter, a Design of Experiments (DOE) is employed, and several output responses are measured and statistically analyzed for this purpose. The characterization procedure is divided into two phases. Initially, the physical foam structure is studied by evaluating the relative density and average strut thickness. The second phase is mechanical characterization through quasi-static compression tests. The compression curves are used to evaluate the mechanical properties of open-cell foams like the plateau stress, densification strain, and energy absorption. All the measured outputs are used as responses for the DOE. Finally, a mathematical model is proposed to interpret the hardening behavior of open-cell aluminium foams during the plateau phase, and the model parameters are investigated against the processing parameters. Among the current investigation findings is the significant effect of the compaction pressure on almost all the measured physical and mechanical responses. On the other hand, the infiltration pressure had a more negligible effect on the relative density, plateau stress, and energy absorption. Finally, the particle size only significantly affected the average strut thickness. The physical and mechanical properties of the produced foams are comparable to commercial open cell aluminium foams. This allows the employment of the current setup to produce foams for industrial applications. The current research outputs include the simple and relatively cheap infiltration casting setup that performs satisfactorily under different processing conditions, the established relations between the process parameters and output parameters, and a mathematical model that can interpret the plateau behavior of open-cell aluminium foams manufactured by infiltration casting.