Fabrication of Bioactive Porous Ti Metal with Structure Similar to Human Cancellous Bone by Selective Laser Melting

Porous titanium (Ti) metal with a structure similar to that of human cancellous bone was fabricated by selective laser melting (SLM) process. SEM observation showed that the core part of the walls of the porous body was completely melted by the laser beam and weakly bonded with small Ti particles on its surface. These Ti particles were joined with the core part by heating above 1000 °C, with remaining micro cavities on their surfaces. Tensile strength of the as-prepared solid rod was 530 MPa and gradually decreased with increasing temperatures to 400 MPa at 1300 °C, whereas its ductility increased with increasing temperatures. NaOH treatment formed fine network structure of sodium hydrogen titanate (SHT) on the walls of the porous Ti metal. The SHT was transformed into hydrogen titanates by HCl treatment and finally anatase and rutile by the heat treatment. Thus treated porous Ti metal formed apatite on its surface in simulated body fluid (SBF) within 3 days.