High quasihydrostatic pressure

Thermal decomposition of samples has been made by the method of prolong exposure at constant temperature on installation of high gas pressure. Specific surface of the samples has been measured by the BET method with accuracy 10% on devise Autosorb-1 (Quantchrome, USA). X-ray powder diffraction data have been obtained with Cu Ka radiation. Samples treatment under high quasihydrostatic pressures (3 GPa, 800°C, 1 h) has been done in the chamber of a high pressure. 

CONSOLIDATION OF AL-CU-FE POWDERS WITH QUASICRYSTALLINE COMPONENT BY USING HIGH QUASIHYDROSTATIC PRESSURES... 

Key words quasicrystalline powders, consolidation, high quasihydrostatic pressure... 

Quasicrystalline powders behave while consolidation in many features like ceramic materials and are consolidated with difficulties. Usually it is performed by HIP technique, but this process takes rather much time and requires complicated equipment. In our former works [1] it was shown that the consolidation of ceramic powders is significantly easier when using high quasihydrostatic pressure that activates particle contact interaction, and high-temperature sintering requires 2-3 min. 

The deviations from the average value for the utmost points of the curve do not exceed 0.1 GPa (6 %). This result is an evidence of the fact that a porous body from the quasicrystalline powder deforms under a high quasihydrostatic pressure as porous bodies from plastic material. Thus, it is shown that the effective pressure P for the consolidation of a powder billet of Al63Cu25Fei2 in the high-pressure apparatus is... 

A large X-ray line broadening in both (1- and /-phases in compacted samples (Fig. 3) is an evidence of a strong plastic deformation in compact samples sintered under high quasihydrostatic pressure. 

Thus, it is shown that the behavior of the two-phase /+P material while high-temperature sintering under high quasihydrostatic pressure is determined by the quasicrystalline /-phase. 

Takemura K (2004) Bulk modulus of osmium High-pressure powder x-ray diffiaction experiments under quasihydrostatic conditions. Phys Rev B 70 012101... 

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