Microstructures and Mechanical Properties of Thermomechanically Processed TiNbSi Alloys for Biomedical Applications
Mechanical properties and elastic modulus were examined in order to clarify the influence on microstructures in Ti-26Nb-xSi, where x= 0.5, 1 in atomic percent, prepared by arc melting, cold rolling and recrystallization heat treatment. On the basis of microstructural observations and phase analyses, it is evidently revealed that the microstructure of as-quenched sample appeared to mixture appearance consisting of mostly bcc-structured β phase and small amount of orthorhombic-structured α″ phase. Elongated structure parallel to the rolling direction was observed in cold rolled samples, and equiaxed structure with the average grain size of about 20μm was developed for the sample after recrystallization heat treatment. Randomly distributed feature of pole figure was characterized without showing a specific texture component in asquenched sample. Rotated cube, α-fiber and γ-fiber texture components were detected in cold-rolled sample. After recrystallization heat treatment the intensity of α-fiber texture component was markedly decreased, while the rotated cube component becomes sharpened and γ-fiber component remains relatively unchanged. From both elastic modulus and strength point of view recrystallization treatment would be desirable to meet the required mechanical properties of the present alloys for biomedical applications.