Preparation and characterization of porous titanium

The traditional polymeric sponge method to produce porous ceramics was used successfully for the first time to make porous titanium and titanium alloy. The porous Ti or Ti-alloy made by such way possess a high porosity (>80%) and reticulate porous structures. Various polyurethane foams were tested and most suitable one was selected. The effects f various pyrolyzing and sintering parameters on the mechanical performance were studied. It was found that the rheological properties of Ti slurry played a critical role in the impregnation process, which were affected by the particle size and shape of the raw powder, type and content of the binder, solid/liquid ratio, pH, sedimentation behaviour of the slurry and the amount of air bubbles. A rapid drying in the processing is important in maintaining a positive replica shape. Due to the high reactivity of Ti (alloy) powder, the sintering was finished under a high degree of vacuum. The po rous Ti-alloy samples obtained were thoroughly characterized with respect to macrostructure, microstructure, and metallurgical texture. The compressive strength of Ti-alloy with about 90% porosity was tested to be from 7 to 13 MPa. This porous titanium can be used directly as the scaffold for bone tissue engineering or porous coating on implants.