Effect of powder mix composition on Al foam morphology

The effect of mix composition on foam morphology has been examined by image analysis carried out on metallographic sections of Al foams prepared by powder metallurgy. Two sets of samples have been prepared by using SiC particles with mean sizes of 37 and 60 µm. Each set consists of 16 groups of samples with different amounts of TiH₂ (0.1, 0.2, 0.4, and 0.6 wt%) and SiC (0.8, 2.8, 6, and 9 wt%).

The distribution of SiC particles on the internal walls of the bubbles has been investigated by scanning electron microscopy observations, which evidenced also the presence of particles of another phase, identified as Ti₃Al by energy dispersion spectroscopy.

Some tests, performed without SiC particles, showed that the Al foaming occurs also under these conditions, however foams exhibit few bubbles of very large size and irregular shape.

Experimental data have been used for training two multi-layer feedforward artificial neural networks. The models represent useful tools for predicting morphologic features of foams for any given mix composition in the training range.