The metal is a dimorphic allotrope of an hexagonal α form that changes into a body-centered cubic (lattice) β form at 882 °C (1,620 °F). The specific heat of the α form increases dramatically as it is heated to this transition temperature but then falls and remains fairly constant for the β form regardless of temperature.Similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but is metastable at ambient pressures. This phase is usually hexagonal (ideal) or trigonal (distorted) and can be considered to be due to a soft longitudinal acoustic phonon of the β phase causing collapse of planes of atoms.
Advantage:
High melting point (3410°C).
Low thermal expansion.
High electrical resistance.
Low vapour pressure.
Good thermal conductivity.
High density.
Application:
Orthopedic implants : artificial joints, metal plate, orthopedic nails, metal orthopedic use rods, intramedullary nail，bone needles, spinal fixation devices.
Heart medicine implants:artificial heart valves, cardiac pacemakers, cardiac catheters and stents within blood vessels.
