Microstructure and mechanical properties of commercially pure titanium foam with varied cell size fabricated by replica impregnation method

The most common sacrificial material for producing metal foam using the replica impregnation method is polyurethane foam (PU) since it is readily available with different cell sizes. This work studied the microstructure and mechanical properties of commercially pure titanium with varied cell sizes. Titanium foams were fabricated using PU foam with four different cell sizes as templates. The results show that as the number of pores per inch (ppi) increased, the apparent density increased, i.e. the cell size decreased, the porosity decreased and the load bearing capacity increased nonlinearly. This work agreed with the scaling law of Gibson and Ashby for determination of the limit stress. However, the Gibson and Ashby model significantly over-predicted the value for quasi-elastic modulus.