Synthesis of Porous Titanium with Directional Pores by Selective Laser Melting

There has been a growing interest and practical importance in producing implants such as artificial joints, bone fixators and spinal fixators with titanium. In order to achieve good bone/implant fixation while avoiding the problem of bone absorption, it is mandatory to reduce the Young’s modulus of titanium while keeping the high strength so as to achieve the compatibility in these mechanical properties with human cortical bone. We have tried to fabricate porous titanium with directional pores by the use of the method based on Selective Laser Melting (SLM), in which complex three-dimensional parts even containing designed shapes of pores can be produced by sintering successive thin layers of metal powder with a laser beam. Here we show that porous titanium with directional pores aligned in the longitudinal direction of the ingot is successfully produced through the use of the SLM process and that high strength and low modulus comparable to those of human bone are simultaneously achieved when these properties are measured in the longitudinal direction of the ingot.