Ferrous Powder Metallurgy Research Articles

The subject matter of this paper, the science of powder partictes coalescence, has developed from powder technology_ Before man learned how to generate high temperatures required in smelting iron ores, he discovered the ways of reducing them at low temperatures to the fine metallic powder. By hot-harnmering this powder, the first iron objects were fabricated. The-monument to the early ferrous powder metallurgy, the famous pillar of Delhi, still stands in that city and owing to the great purity of the iron used in its fabrication, successfully resisted corrosion for more than a millennium_ A new age of powder metallurgy was introduced at the turn of this century for very similar reasons, namely to fabricate the filaments of refractory metals such as tungsten, osmium and molybdenum for the then budding incandescent lamp industry. The high melting point of tungsten exceeding 3000°C precluded the use of the conventional metallurgical techniques of melting and casting. Since then powder technology has made steady progress and today it has become one of the most important methods of materials fabrication. Although from the beginning, modem powder metallurgy was researchminded, an understanding of the basic mechanisms underlying powder metallurgical processes was slow to develop. A powder compact is a hopelessly complicated system. The details of the geometry of the contacts between the individual particles, where the sintering process takes place, are so complex and so unknown that the results of measurements of the changes of the compact properties, such as density, as a function of time and temperature cannot lead

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