Laser-deposited Ti-Nb-Zr-Ta orthopedic alloys

The complex quaternary Ti‐35Nb‐7Zr‐5Ta orthopedic alloy has been successfully deposited from a powder feedstock consisting of a blend of elemental titanium, niobium, zirconium, and tantalum powders, using the laser engineered net‐shaping (LENS™) process. In the as laser‐deposited form, these alloys exhibit a substantially higher tensile strength as compared with more conventionally processed counterparts of similar composition, while maintaining excellent ductility and a low modulus. Furthermore, the as‐deposited alloys appear to exhibit a texture, with a substantially large number of grains of the β phase aligning one of their axes nearly normal to the substrate or parallel to the growth direction. The microstructure of the as‐deposited as well as tensile‐tested alloys have been characterized in detail using scanning electron microscopy (SEM), orientation microscopy (OM), and transmission electron microscopy (TEM). Formation of a high density of shear bands, possibly arising from slip localization due to precipitates of the ω phase in the β matrix, is clearly evident in the tensile‐tested sample. The enhanced tensile strength and low modulus in these laser‐deposited alloys coupled with the ability to form near‐net shape components makes LENS an attractive processing technology for orthopedic implants. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006