Titanium is the chemical element with atomic number 22, with the
symbol Ti. The titanium variant, although attested in French since 18727, is
considered to be an incorrect anglicism.
Titanium belongs to group 4 of the periodic table (titanium group) with
zirconium (Zr), hafnium (Hf) and rutherfordium (Rf), it is a transition metal.
This element is found in many minerals, but its main sources are rutile and
anatase.
The pure titanium body is a light, resistant metal, metallic white in
appearance, which resists corrosion. It is mainly used in light and resistant
alloys, and its oxide is used as a white pigment. The industrially interesting
properties of titanium are its resistance to corrosion, often associated with
resistance to erosion and fire, biocompatibility, but also its mechanical
properties (resistance, ductility, fatigue, etc.) which in particular make it
possible to shape thin and light pieces like sporting goods, but also orthopedic
prostheses.
Erosion
The very adherent and hard oxide layer explains the longevity of titanium parts
subjected to the impacts of particles in suspension in fluids. This effect is
amplified by the ability of this layer to regenerate. Erosion in seawater is
increased by a higher flow or a smaller particle size.
Strength and ductility
Titanium is considered to be a metal with high mechanical resistance and good
ductility under normal temperature conditions. Its specific resistance (tensile
strength / density ratio) is, for example, higher than that of aluminum or
steel. Its resistance is decreasing at temperature with a flatness between −25 กใ
C and 400 กใ C. Below −50 กใ C, in cryogenic temperature ranges, its resistance
increases and its ductility decreases greatly.
Wear and seizure
To date, no satisfactory solution has yet been developed. We mainly tried
oxidation, nitriding, boriding and carburization. We encounter many
technological difficulties of realization and adhesion. Let us add that the
surface treatments of titanium, modifying the nature or the structure of the
surface, are to be used only with the greatest caution and after a thorough
study of their influence; they generally have a more or less pronounced harmful
effect on resistance and fatigue.
copper aluminum lead Zinc tin nickel iron
magnesium bismuth manganese chromium cobalt titanium
Tungsten vanadium niobium indium molybdenum antimony
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