Method using variable-temperature and variable-pressure hydrothermal method to prepare MgAl2O4 complex-phase nano powder and application of method

Abstract

The invention discloses a method using a variable-temperature and variable-pressure hydrothermal method to prepare MgAl2O4 complex-phase nano powder and application of the method. The method includes: dissolving, settling and washing soluble magnesium salt, aluminum salt and zirconium oxychloride separately to obtain precursors, adding the precursors into a high-pressure reaction kettle in batches, and using the variable-pressure and variable-temperature hydrothermal process to prepare the MgAl2O4 complex-phase nano powder. The method has the advantages that zirconium oxide grains in the prepared MgAl2O4 complex-phase nano powder attach to the surface of magnesium aluminate spinel to grow in situ, even grain size is achieved, and the problem of phase unevenness is solved; ceramic prepared by the powder contains the MgAl2O4 phase and the Al2O3 phase, the defect that the zirconium-oxide-main-phase ceramic is large in density, high in cost and inapplicable to high-temperature environments is overcome, and the ceramic has comprehensive performance and cost advantages and can be used for preparing structural parts such as mobile phone shells (back plates), card supports, watch shells and bearings.

Description

technical field [0001] The invention relates to the field of multiphase ceramic powder, in particular to the preparation of MgAl by a hydrothermal method with variable temperature and variable pressure 2 o 4 Method and application of multiphase nanopowder. Background technique [0002] In the past ten years, with the rapid development of consumer electronics such as mobile phones, structural parts such as mobile phone casings (back panels) have made remarkable progress. Especially in the structural design of consumer electronic housings in the future 5G era, traditional metals pose a huge challenge to antenna design due to their inherent shielding effects, while plastics have inherently low strength shortcomings that limit their use in large-size screens. , ultra-thin applications, and with the improvement of consumer aesthetics, traditional metal casings and plastic casings are difficult to impress consumers. [0003] Thanks Al 2 o 3 and ZrO 2 Ceramics have high tough...

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Problems solved by technology

[0004] In view of this, the present invention aims at the deficiencies existing in the prior art, and its main purpose is to provide a kind of variable temperature variable pressure hydrothermal method to prepare MgAl 2 o 4 Method and application of multiphase nanopowder, using the method to prepare MgAl 2 o 4 The ceramics prepared by the composite nanopowder overcome the defects of high density and high cost of the main phase ceramics of zirconia, and are not suitable for high-temperature environments; the disclosed multi-step hydrothermal process makes the zirconia grains adhere to the magnesium-aluminum spinel The in-situ growth on the surface of different phases is evenly distributed in the nanometer size, which overcomes the problem of uneven phase distribution and reduces the possibility of forming uneven microstructures; the further disclosed hydrothermal process of variable temperature and pressure controls the initial powder The grain size and morphology of the body; at the same time, the presence of magnesium-aluminum spinel in the powder induces other grains to easily form equiaxed crystals when forming ceramics, reducing stress concentration and improving the overall performance of ceramics

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