Near Net Shape Fabrication of Highly Porous Titanium Parts

摘要

The application a pore-forming additive allows the powder metallurgical production of highly porous titanium. Porosity of up to 75 % and pore size of up to 2 mm are directly related to the additive characteristics and can be well adjusted by fractionating the spacer particles. In addition, the pore-forming additive may enhance the stability of the pressed compacts. This fact enables machining of the green compacts to achieve a complex shape of components. Shaping is followed by removal of the spacer material, which decomposes during heating and subsequent sintering. The requirements of each production step as well as the limitations of the process are presented. The efficiency of the production route was demonstrated with the example of the prototype of an acetabular cup provided for hip replacement as well as on a bar with graded porosity. Furthermore, some characteristic properties of highly porous titanium parts are discussed.