Effect of Mg Powder’s Particle Size on Structure and Mechanical Properties of Ti Foam Synthesized by Space Holder Technique

Abstract

Titanium foam has been the focus of special attention for its specific structure and potential applications in purification, catalyst substrate, heat exchanger, biomaterial, aerospace and naval industries. However, the liquid-state foaming techniques are difficult to use in fabricating Ti foam because of its high melting temperature and strong chemical reactivity with atmospheric gases. Here, the fabrication of Ti foams via the powder metallurgy route was carried out by utilizing both magnesium powders and magnesium particles as spacer holders, and Ti powders as matrix metal. The green compacts containing Ti powder, Mg powder and Mg particles were heated to a certain temperature to remove the magnesium and obtain the Ti foam. The results show that the porosities of the obtained Ti foam are about 35–65%, and Young’s modulus and yield strength are found to be in the ranges of 22–126 MPa and 0.063–1.18 GPa, respectively. It is found that the magnesium powders play a more important role than the magnesium particles in the deformation and the densification of the green compact during the pressing, and the pore structure of Ti foam depends on the amount and the size of the magnesium spacer holders after sintering.

Effects of the Space Holder Shape on the Pore Structure and Mechanical Properties of Porous Cu with a Wide Porosity Range

“…The porosity of the porous copper increased from 38.48 ± 0.91% to 66.47 ± 1.06%, and the yield strength decreased from 42.8 ± 4.6 MPa to 6.9 ± 0.9 MPa when the space holder of bimodal K 2 CO 3 : NaCl was 1:2, as their contents increased from 30% to 70%, according to Ray et al [ 5 ] The total porosity of porous copper increased from 27.5% to 67.1%, and the elastic modulus (C 11 ) decreased from 59.4 ± 0.2 GPa to 1.0 ± 0.2 GPa when the content of K 2 CO 3 used as the space holder increased from 0 to 54.4%, according to Jana et al [ 6 ]. Luo et al [ 7 ] showed that the elastic modulus of titanium foam decreased with the increasing size of the magnesium particles, while the porosity decreased, etc. However, little attention was paid to the shape of the space holder, even when the study of the shape of the metal powder extended the scope to the entire porous metal.…”