Rheological properties of commercially pure titanium slurry for metallic foam production using replica impregnation method

Open-cell titanium foam can be produced by the sacrificial polymer foam impregnation method. It is important to control and understand the rheological properties of titanium slurry for the commercial production of titanium foam. The effects of titanium solid loading, binder (PVA) content and dispersing agent (Dolapix) content on the viscosity of titanium slurry were studied. The results show that the viscosity of titanium slurry is dependent on titanium solid loading and PVA content but independent on Dolapix content. However, Dolapix is required to prevent rapid sedimentation. The optimum titanium slurry composition is 75 wt.% of titanium powder, 1.5 wt.% of PVA, 1.0 wt.% of Dolapix and 22.5 wt.% of water. It was used to produce titanium foam with a porosity level of 84%, 0.47 wt.% of carbon content and 0.3 wt.% of oxygen content. From the compression test, Youngʹs modulus of the titanium foam is 0.58 GPa, the plateau stress is 10 MPa and the densification strain is 78%. The good mechanical properties were achieved because there was limited contamination from organic compounds or from the atmosphere during sintering.