81 Introduction

Titanium has often been referred to as the "wonder metal" with excellent strength, ductility, and fracture resistant characteristics in combination with superior environmental resistance. However, significant difficulties in obtaining titanium from its ores (mainly rutile and ilmenite), combined with stringent processing requirements (both factors implying high cost), greatly slowed commercialization. However, today there is a vibrant titanium industry potential poised for breakthrough into the high-volume, cost-competitive automobile marketplace.

Titanium is a metal element of Group IVB of the periodic table, with a melting point of 1675°C, an atomic weight of 47.9, and a density of 4.5 g/cm3. The element is the fourth most abundant structural metal in Earth's crust (behind Al, Fe, and Mg), occurring mainly as rutile (TiO2) and ilmenite (FeTiO3).

Metallic titanium use can be divided into two main categories: corrosion resistance (essentially titanium alloyed to a minor extent) and structural use (for which titanium is more highly alloyed to increase the strength level while maintaining usable levels of other mechanical properties such as ductility). While the market for metallic titanium is showing a generally upward trend, the major use of titanium, as TiO2 a white compound with high refractive index, is as a pigment "whitener" in paints, paper, rubber, plastics, and the like at about 20 x the use level of metallic titanium.

0 0

Post a comment