Titanium and NiTi foams for bone replacement

Extensive development in porous titanium and titanium alloys over the past 40. years has successfully opened up a wide range of biomedical applications and helped offer a view into the next generation of metal implants. This chapter will first provide basic understanding of the materials science underlying the use of titanium-based foams, including both titanium alloys and nickel titanium (NiTi) shape-memory alloys, as bone replacement materials. It will then review recent developments in fabrication techniques that allow these alloys to fulfill implant requirements, and also their current limitations, which lead to three generations of currently available foam structures and their properties in existing commercial products and research in progress. Finally, future trends for titanium-based foams are discussed.