Mechanical properties and deformation behavior of β-type titanium alloy (TNTZ) drawn wires

Abstract

Tensile and fatigue properties are important mechanical properties in drawn wires for biomedical and dental applications because of the credibility against the monotonic loading fracture or fatigue failure. The mechanical properties and deformation behavior of drawn wires of Ti-29Nb-13Ta-4.6Zr with diameters of 1.0 mm and 0.3 mm (designated as TNTZ d1.0 and TNTZ d0.3) were investigated to know a potential for biomedical and dental applications in this paper. The microstructure of forged Ti-29Nb-13Ta-4.6Zr subjected to a solution treatment at 1063 K (TNTZ ST) comprises a single β phase with an average diameter of 25 μm. While that of TNTZ d1.0 comprises a needle-like single β phase elongated parallel to the drawing direction. Tensile strengths of TNTZ d1.0 and TNTZ d0.3 are approximately 740 MPa and 800 MPa, respectively. While both elongations are nearly equal to each other (approximately 5.0%). The elastic modulus of TNTZ d1.0 is approximately 50 GPa and that slightly smaller than approximately 55 GPa of TNTZ d0.3. The notch-fatigue limit of TNTZ d1.0 is 250 MPa. TNTZ ST exhibits the maximum elastic strain of approximately 1.4%. And the stress-strain curve shows a single gradient during elastic deformation region. The stress-strain curves of TNTZ d1.0 and TNTZ d0.3 in the elastic deformation region show two gradients, and the values of the maximum elastic strains in both wires are approximately 2.9% and 2.8%, respectively. © 2005 The Japan Institute of Metals.