Powder metallurgy route aluminium foams: a study of the effect of powder morphology, compaction pressure and foaming temperature on the porous structure

摘要

The aim of the present research is the production of metal foams using powder metallurgy route with gas releasing particles, in order to further analyze the effect of different parameters in the foams final porosity and internal structure. The parameters examined included the powder morphology, the compaction pressure and the foaming temperature. During the foaming stage, for each set of parameters the porosity-time (P_f-t) diagrams were developed and examined. Results indicate that the highest foaming efficiency (η=P_(fmax)) was observed at the specimens with the fine aluminium powder, with high (700 MPa) compaction pressure and high foaming temperatures (800°C). Consequently, compression tests were performed on those foamed specimens in order to investigate their s-e response. From the experimental s-e results of the foamed specimens, average compressive strength and density were estimated and presented for comparison with existing literature results on periodic and stochastic metal foams.