ABSTRACT
Many new materials for use in manufacture have been invented, developed and produced in the 20th century. Plastics, composites and ceramics are now well established for a wide range of applications. But metals, together with wood and concrete, still retain a dominant position in terms of the tonnages which are used annually. Although the new materials may provide a better combination of physical and mechanical properties for some applications, or simply improved aesthetic appeal, they have not made significant impact on the quantities of metal used. If wood and cement are excluded, the annual production of metals exceeds the quantity of all other construction and manufacturing materials. Steel continues to dominate the market; in tonnage terms the world production of just under 800 million tonnes of steel per annum is 93% of the total output of metals and is roughly five times the total production of composites, plastics, cermets and all the other metals. In contrast, only 11 million tonnes of plastics were made in 1989.
