Preparation method for Al-Pd-Mn quasicrystal

Abstract

The invention relates to a preparation method for a Al-Pd-Mn quasicrystal. The Al-Pd-Mn quasicrystal includes, by atomic ratio, 70%-72% of Al, 18%-21% of Pd and 7%-12% of Mn. The method includes the steps that high-purity Al powder, high-purity Pd powder and high-purity Mn powder are evenly mixed, injected into a hard alloy mould, and pressed in a hydraulic tablet press under 2-4 MPa for 100-300 seconds to obtain a reserved block; the reserved block is mounted into a boron nitride crucible, a pre-dried tubular graphite oven body, the boron nitride crucible, a boron nitride piece, a pyrophyllite piece and a graphite piece are assembled and placed in a six-surface diamond presser, setting pressure is controlled to be isostatic pressure ranging from 3 GPa to 6 GPa, and the temperature is controlled to rise to 850-950 DEG C and kept for 30-60 minutes; and the temperature is decreased to 650-850 DEG C and is kept for two to six hours. The preparation method is simple in process, low in energy consumption and high in efficiency; the quasicrystal is prepared from the raw materials at a time only with conventional equipment; the prepared quasicrystal has excellent quality performance and good mechanical performance and can be widely applied.

Description

technical field [0001] The invention belongs to the technical field of metal materials, in particular to a method for preparing quasicrystals. Background technique [0002] In 1984, D. Shechtman, an Israeli scientist working in the US National Bureau of Standards, discovered a peculiar phase with metallic properties—the icosahedral phase in the rapidly solidified Al-Mn binary alloy. This is a new crystallographic structure. The electron diffraction spots of this new phase are quite sharp and show five-fold rotational symmetry that is not allowed by the crystal structure, so it cannot be calibrated by any Bravais lattice. This new phase is a solid-state ordered phase with long-range quasi-periodic translational order and amorphous rotational symmetry, which was soon called a quasicrystalline phase. The special structure of quasicrystals has aroused great interest and prompted researchers to search for quasicrystals in related systems. In the first few years, the research s...

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Problems solved by technology

The latter methods can obtain high-quality single crystals, but require extremely strict sample pretreatment and precise control of heating temperature and time.

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