Recent Developments in power Metallurgy of non-ferrous Metals

THE first large-scale application of powder metallurgical
techniques started with the production of ductile tungsten -a non-ferrous metal, by W. D. Coolidge in 1910. This date can be considered as the renaissance of powder metallurgy, because this invention was the basis for the development of the modern incandescent lamp industry. In this context one has to forget about the prehistoric and primitive powder metallurgy as well as the production of sintered platinum by the British and Russians in the first half of the 19th century. The development of ductile tungsten led to large scale production of refractory metals such as tungsten , molybdenum ; contact materials, such as tungsten- copper, tungsten-silver : porous products. such as bearings, filters and also cemented carbides. These materials could not be produced by the conventional techniques. Later developments include the high temperature high strength materials, such as cermets, dispersion hardened materials and fibre rein-forced composites The entry of powder metallurgy into
the competitive field for the production of structural parts and semi-finished products by the continuous compaction of metallic powders is a remarkable one. Today powder metallurgy process can compete on equal terms with other processes. It is no longer the last resort. Among the various methods available for the processing of metals, powder metallurgy occupies a unique place. It can he used not only for making a variety of products for different applications like other methods, but also to create new materials which are either difficult or impo-ssible by the conventional techniques.