PM processed titanium foam: influence of morphology and content of space holder on microstructure and mechanical properties

Ti foam has been synthesised by powder metallurgy route using acicular and fine urea particles as space holder. Pore morphology and distribution and compressive behaviour of samples have been studied for different urea particle morphologies and volume fractions. Acicular urea particles generated islands of acicular porous regions with a large number of micropores. Fine pores with improved homogeneity were obtained using finer urea particles. The plateau regions in the case of using acicular particles were much distinct and obtained at a lower level of porosity compared to those incorporated with fine urea particles. Acicular urea particles became more effective towards attaining higher ductility and plateau area, the latter suggesting superior energy absorption (damping) capacity of the processed (foam) samples. The study also demonstrates that the mode of pore distribution in the matrix makes a greater contribution compared to the pore size towards controlling the end properties of the samples.