Of Volume 2.- Ferrous Powder Metallurgy.- Some Aspects of the Sintering of Iron Powder.- The Mechanism of Sintering of?-Iron.- Alpha and Gamma Phase Sintering of Carbonyl and Other Iron Powders.- Investigation of the Activated Sintering of Iron Powder.- The Use of Byproduct Steel Powder from Ball-Bearing Production in Powder Metallurgy.- The Corrosion Resistance of Sintered Austenitic Stainless Steel.- Dispersion Strengthening.- Dispersion-Strengthened Nickel by Compaction and Rolling of Powder Produced by Pressure Hydrometallurgy.- On the Mechanisms of Plastic Deformation of SAP-Type Alloys.

Aluminum P/M parts can be production sintered in various types of furnaces and atmospheres. Selection of sintering furnace depends upon economic considerations and production rates desired. Batch furnaces have lowest investment costs and are adequate for low to medium production whereas continuous furnaces are more costly but provide higher production rates. strong, well-sintered P/M parts can be obtained in atmos pheres of nitrogen, dissociated ammonia and in vacuum. Atmos phere selection depends upon facilities available within individual plants plus property requirements. Highest strengths are produced in nitrogen followed by vacuum and dissociated ammonia. Repro ducible dimensions can be achieved with proper attention to com pact density, sintering temperature, dew point and atmosphere. REFERENCES 1. J. H. Dudas and W. A. Dean, "'llie Production of Precision Aluminum P/M Parts," International Journal of Powder Metallurgy, Vol. 5, April, 1969. 2. P. F. Mathews, "Effects of Processing Variables on the Properties of Sintered Aluminum Compacts,!! International Journal of Powder Metallurgy, Vol. 4, October, 1968. 3. J. H. Dudas and K. J. Brondyke, "Aluminum P/M Parts - Their Properties and Performance,!! Technical Paper No. 700141, Society of Automotive Engineers, Inc., Two Pennsylvania Plaza, New York, New York, 10001. 4. K. R. Van Horn (Editor), Aluminum Vol. I, pp. 26-28, American Society for Metals, Metals Park, Ohio, 1967.

Powder metallurgy literature in the English language includes a large number of books and several thousand articles in various journals. The rate of growth of this literature increases from year to year. It covers well the whole field of powder metallurg- materials, processes and products - with two exceptions: friction and antifriction branches of powder metallurgy. This lack of information has nothing to do with scientific or technical considerations, and definitely has nothing to do with lack of initiative in the development of these materials. The industry concerned with the production of friction and antifriction materials is continually developing new products and techniques and produc tion is steadily growing. However, most companies working on these materials regard their experiences and new advancements as "proprietary" and, for competitive reasons, are not interested in publishing in the technical literature except for very perfunctory and usually highly commercial papers. Very little work on fric tion and antifriction materials is going on in independent labora tories and university laboratories, although fundamental studies in this field offer very interesting aspects.