Laws of densification of powder materials

Autor: S. S. Kiparisov, V. E. Perel'man, O. V. Roman
Rok vydání: 1977
Předmět:
Zdroj: Soviet Powder Metallurgy and Metal Ceramics. 16:937-943
ISSN: 1573-9066
0038-5735
Popis: 1. The density of a porous (powder) body being pressed is a function of the stress tensor, but is not uniquely related to the latter's greatest component. The intensity of the compact densification process depends directly on the relative magnitude of the deviator component of the stress tensor. 2. The decrease in the porosity of a material during pressing may follow any one of a multitude of possible trajectories within an OAB field representing, in a diagram of normal stress vs tangential stress, all combinations of stresses acting in a compact at which the latter experiences densification. 3. The functions describing the relation between pressing pressure and compact density in the orthodox pressing techniques and the coefficients of these functions are determined by the character of the variation of the parameters K and γ with compact density, and are thus secondary relative to the latter functions. 4. For the materials investigated the equationsK=Kγ and ϱ≈ϱ(γ) are approximately linear only in a relatively narrow range, of density variation (between γ≈60% and γ≈80%). This leads to the conclusion that the relation between pressure and density in pressing in rigid dies and in isostatic vessels varies in character during the whole densification process.
Databáze: OpenAIRE
Externí odkaz: