Examination of the defective structure of tungsten powers by the electron-positron annihilation method

Powder Metallurgy and Metal Ceramics -     

Special features of mass transfer in sintering of highly dispersed metallic powders

At the present time, the advantages of powder metallurgy acquire new emphasis due to the preparation of materials in a highly dispersed state. When coarse powders are replaced in a technological process by highly dispersed powders, the sintering temperature of pressed preforms can be decreased. which gives sintered articles with a more homogeneous and fine-grain structure. The broadened application range of highly dispersed powders (HDP) creates difficulties caused by the scarceness of data on their preparation, storage, shaping, and sintering. This is associated with methodological difficulties that appear in the investigation of the effect of the dispersity of the powder particles on the special features of compaction of preforms that have different physicochemical states and different chemical and phase compositions of the surface and the bulk of the particles. The present article concerns some special features of the morphology, structure, and physicochemical properties of HDP prepared under the conditions of low-temperature plasma.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 17–21, March, 1996.