[en] First, significance and advantages of sintered materials consisting of two layers are pointed out. By means of the two layer powder pressing technique metal powders are formed resulting in compacts with high accuracy of shape and mass. Attributes of basic powders, different filling methods and pressing techniques are discussed. The described technique is supposed to find further applications in the field of two layer compacts in the near future

[en] A method is described for manufacturing compact nuclear fuel bodies from particulate nuclear fuel composed of coated particles. A problem arises when the compact bodies are required to be of elongated form as the pressures required to achieve substantially uniform densities are necessarily high and invariably result in unacceptable damage to the particles. The method involves sequentially introducing fractions of the coated particles into an elongated cavity between applications of a controlled compacting tamping means along the longitudinal axis of the cavity. (UK)

[en] The different origins of cracks in sintered parts are examined. Non-homogeneous density seems to be of secondary importance, whereas the evacuation of air, friction and elastic deformation of punches, cause defects of varying shape depending on the cause. Apart from means aimed at eliminating the causes of these defects, improvement is possible during pressing operations using powders with enhanced green strength, by maintaining pressure during ejection of the compact, and by evacuating part of the occluded air

[en] The present paper provides a basis for defining a mix design method specifically tailored to rubberised asphalt that takes into account the behaviour of crumb rubber. An analytical approach to quantifying the recovered deformation of crumb rubber in the post-compaction phase has been developed in order to adjust the number of gyrations proposed by the Superpave method for compacting specimens of hot mix asphalt using a Superpave gyratory compactor. The maximum allowable amount of rubber has been calculated. Finally, a step-by-step protocol has been proposed in order to fabricate and compact crumb rubber modified mixtures with the gyratory compactor.

[en] Description is given of a method for preparing compacts with high matrix density. The method is characterized by the steps of forming the mixture by simultaneously pouring the components directly into a compacting matrix comprising coated particles and a graphite binder mixture in the granular form, then compressing the compact after having brought the material to be compacted to a temperature at which the binder is in the fluid state. The method can be applied to the manufacture of compacts for high temperature nuclear reactors

[en] Powder metallurgy is a conventional technique for making engineering articles from powders. Main objective is to produce final products with the highest possible uniform density, which depends on the initial loose powder characteristics. Producing, handling, characterizing and compacting materials in loose powder form are part of the manufacturing processes. Density of loose metallic or ceramic powder is an important parameter for die design. Loose powder density is required for calculating the exact mass of powder to fill the die cavity for producing intended green density of the powder compact. To fulfill this requirement of powder metallurgical processing, a loose powder density meter as per ASTM standards is designed and fabricated for measurement of density. The density of free flowing metallic powders can be determined using Hall flow meter funnel and density cup of 25 cm/sup 3/ volume. Density of metal powders like cobalt, manganese, spherical bronze and pure iron is measured and results are obtained with 99.9% accuracy. (author)

No abstract available

[en] A compact metamaterial element structure is proposed which is characterized with dual-planar meander line (DML) patterns. Compared with existing single planar solutions, the new design is with an extremely reduced resonance frequency. Good agreement is observed between the simulated and measured results. To strengthen the compacting effect, the effective material properties are further retrieved and compared. By calculating the ratio of resonator size to resonating wavelength, the proposed DML design is featured with a deep subwavelength element size at the order of 1/30 wavelength. We remark that this compacting effect does not sacrifice the functional bandwidth of negative permittivity. The negative permittivity bandwidth for the DML design is nearly 70%, much larger than those of existing single planar structures. By utilizing more advanced fabrication technology, the DML element size can be further decreased if the meander lines are made thinner in future. (paper)

[en] This patent concerns an abrasive compact comprising diamond or cubic boron nitride or mixtures thereof held in a matrix of a refractory substance and a substance which dissolves the abrasive particle to at least a limited extent. The compact may be made by subjecting a powdered mixture of the ingredients to conditions of temperature and pressure at which the abrasive particle is crystallographically stable and the solvent substance acts to dissolve the abrasive particle. The refractory substance and solvent substance are preferably so chosen that during compact manufacture there is interaction resulting in the formation of a hard material

[en] Components of active cadmium electrode mass, two- and multicomponent cadmium oxide-based mixtures have been studied for their compression properties. Components of active mass and factors most destabilizing compaction of electrodes are revealed. Ranges of solar fraction and polyvinyl alcohol concentrations are found in which the compaction process is extremely unstable and active material loading greatly dependes on the amount of liquid component in the mass