Physical metallurgy of Ti–Ni-based shape memory alloys

Perspectives on Titanium Science and Technology

https://mech.pg.edu.pl/documents/14057592/14057638/1611.pdf

Fabrication methods of porous metals for use in orthopaedic applications

https://www.tpbin.com/Uploads/Subjects/643149a0-8194-4c67-bf05-73fae6f0d14f.pdf

Development of new metallic alloys for biomedical applications

Young's modulus as well as tensile strength, ductility, fatigue life, fretting fatigue life, wear properties, functionalities, etc., should be adjusted to levels that are suitable for structural biomaterials used in implants that replace hard tissue. These factors may be collectively referred to as mechanical biocompatibilities. In this paper, the following are described with regard to biomedical applications of titanium alloys: the Young's modulus, wear properties, notch fatigue strength, fatigue behaviour on relation to ageing treatment, improvement of fatigue strength, fatigue crack propagation resistance and ductility by the deformation-induced martensitic transformation of the unstable beta phase, and multifunctional deformation behaviours of titanium alloys.

Mechanical biocompatibilities of titanium alloys for biomedical applications.

Mechanical properties of porous titanium compacts prepared by powder sintering

Young's modulus and tensile strength were investigated in relation to phase transformation and microstructural changes occurring during cold rolling and subsequent heat treatment using β (Ti-35 mass%Nb)-4 mass%Sn and (Ti-35 mass%Nb)-7.9 mass%Sn alloys. Stress-induced a" martensite is generated on cold rolling of (Ti-35Nb)-4Sn whose martensitic transformation start temperature is around room temperature. Young's modulus in the rolling direction is lowered by the generation of stress induced a" phase with preferred texture, while it is recovered by the reverse martensitic transformation to ft at 523 K. The reverse transformation yields fine β grains which are elongated approximately along the rolling direction and have an average grain size in width of less than 1 μm. This fine microstructure leads to high strength over 800 MPa with keeping low static Young's modulus of 43 GPa. In contrast, mechanical properties of (Ti-35Nb)-7.9Sn in which matensite is not stress-induced are not so significantly improved by cold rolling and heat treatment.

/pdf/beta-tinbsn-alloys-with-low-young-s-modulus-and-high-2wtzo2muwg.pdf

Beta TiNbSn Alloys with Low Young's Modulus and High Strength

Composition dependence of Young's modulus inTi-V and Ti-Nb binary alloys and Sn-added ternary alloys quenched fromphase region was investigated at room temperature in relation to the stability ofphase. A minimum of Young's modulus in the binary alloys appears at such a composition that athermal ! phase transformation is almost completely suppressed. Formation of isothermal ! phase by aging after quenching increases Young's modulus. Sn addition to the binary alloys suppresses or retards ! transformation, thereby decreasing Young's modulus. Optimization of alloy composition in Ti-Nb-Sn alloys leads to low Young's modulus of about 40 GPa. The composition dependence of Young's modulus obtained experimentally in this study can be qualitatively explained by the theoretical discrete-variational Xcluster method.

/pdf/beta-ti-alloys-with-low-young-s-modulus-42krsnjx06.pdf

Beta Ti Alloys with Low Young's Modulus

Martensitic transformation and tensile properties of 4 to 5 mol%Sn-doped Ti–16 mol%Nb alloys consisting of biocompatible elements were investigated to provide superelasticity for biomedical applications as a function of heat treatment and Sn content. Martensitic transformation (bcc to orthorhombic structure) is accelerated at such quenching conditions that the bcc parent phase is slightly decomposed. Martensitic transformation temperature decreases rapidly with increasing Sn content. In-situ optical microscopic observation on cooling and heating indicates that the martensite is thermoelastic, corresponding to small temperature hysteresis between the martensitic and the reverse transformations, which is determined by differential scanning calorimetry. By controlling the heat treatment condition and Sn content, large superelastic strain is obtained at room temperature.

/pdf/effect-of-heat-treatment-and-sn-content-on-superelasticity-415r19c8fu.pdf

Shuji Hanada

Papers

Mechanical properties of porous titanium compacts prepared by powder sintering

Beta TiNbSn Alloys with Low Young's Modulus and High Strength

Beta Ti Alloys with Low Young's Modulus

Effect of Heat Treatment and Sn Content on Superelasticity in Biocompatible TiNbSn Alloys

The bone tissue compatibility of a new Ti–Nb–Sn alloy with a low Young’s modulus