Processing of aluminium foam by infiltration of NaCI space holder / Razmi Noh Mohd Razali

The main objective of this study was to fabricate aluminium foam with central pillar by casting replication process incorporated with NaCl space holder. The effect was investigated taken into account different space holder sizes. It is also aimed to determine different pore size and in cooperation of a central pillar towards aluminium foam. In this research work, the Gibson-Ashby model with different sizes and modified geometry were used subsequently subjected to compression simulation using CATIA software is presented. Next, the mould is designed and fabricated in advance of casting replication processing set up. It was then followed by optimization parameters processing in term of temperature, argon gas flowrate and material weight. Aluminium foam with and without central pillar with different sizes were prepared based on the abridged optimization chart and further water leaching took place to remove the space holder completely. The space holder and aluminium properties were determined by using Thermogalvametric Analysis (TGA) and Spectrometer correspondingly. The characteristics of the aluminium foams were then characterized by density and porosity percentage, stereoscopic, 3D aluminium foam modeling, Scanning Electron Microscopy (SEM) and its mechanical behavior by uniaxial compression. Aluminium foams with the porosity in the range of 59 - 72% and aluminium foams with central pillar in the range of 50 - 63% were achieved. Increasing the size of the NaCl particle increases the foam porosity and at the same time decreases the foam density. Aluminium foam 1 mm with central pillar with the smallest pore size and lower mean porosity percentage of 49.85%) presented the highest mechanical properties; compressive strength (215.12 MPa), Young's Modulus (4.22 GPa) and high energy absorption (33.90 MJ/m3 ). The present work specimens are believed capable to be applied for functional and structural applications as the present work samples improved significantly in terms of its mechanical properties.