A kind of preparation method of hydrogen absorbing element

Abstract

The invention relates to a preparation method of a hydrogen absorption component. The preparation method comprises the following steps: suspension induction melting or medium-frequency induction melting is carried out on a raw material metal and / or an intermediate alloy to obtain a target ingredient alloy ingot; after vacuum activation of the hydrogen absorption alloy ingot, hydrogenation treatment is carried out to obtain hydrogen-containing alloy particles; the alloy particles undergo ball-milling and screening to make all materials meet jet-milling feeding requirements; the alloy particles are ground into a powder by jet-milling; hydrogenated alloy particles undergo spheroidizing and dehydrogenation by radio frequency plasma discharge spheroidizing; and the obtained powder is pressed or sintered to prepare the hydrogen absorption component. Hydrogen adsorption properties of the hydrogen absorption component prepared by the above method are obviously better than those of a hydrogen absorption component prepared by traditional preparation methods such as a direct crushing method and a hydrogenation crushing method. The prepared hydrogen absorption component has excellent hydrogen absorption properties at high temperature and can replace existing hydrogen absorption components for solar vacuum tubes.

Description

technical field [0001] The invention relates to a method for preparing a hydrogen-absorbing element, in particular to a method for preparing a hydrogen-absorbing element for a high-temperature vacuum heat collecting tube for solar thermal power generation. Background technique [0002] With the rapid rise of the new energy technology industry, solar thermal utilization technology has also been greatly developed and popularized, especially solar thermal power generation technology. The high-temperature vacuum heat collecting tube is one of the core components of solar thermal power generation. At present, the high-temperature solar vacuum heat collecting tube widely adopts a double-layer airtight structure with a stainless steel tube coated with a heat-absorbing coating as the inner tube and a transparent glass tube as the outer tube. There is a vacuum between the glass tube and the stainless steel tube. During the long-term use of the heat collecting tube, the heat transfer...

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Problems solved by technology

This method has a simple process and low cost, but due to the limitations of the crushing and grinding equipment itself, it is not suitable for materials with high toughness and strength, which greatly limits the materials used for hydrogen absorbing components. The composition of the hydrogen absorbing element usually adopts a brittle alloy with a solid solution alloy of titanium or zirconium as the main phase, and an intermetallic compound as the second phase by adding a third metal element; secondly, during the crushing process, due to the alloy and the broken High-intensity collision and friction of equipment cavity walls and media will introduce a large amount of impurities; third, the general particle size of hydrogen-absorbing material powders prepared by this method is less than 300 meshes, which will cause molding quality problems due to fluidity problems. The specific surface area of ​​the hydrogen absorbing element is affected, which affects the activation temperature and hydrogen absorbing performance of the hydrogen absorbing element

[0004] It is also reported in the literature that hydrogen-absorbing components are prepared by hydrogenation pulverization. This method utilizes the characteristics of the hydrogen-absorbing alloy to generate a hydride phase with high brittleness after absorbing hydrogen, and solves the problem of high-strength and high-toughness alloys in crushing. However, in the dehydrogenation process, it is extremely difficult to achieve complete dehydrogenation of the hydrogen-absorbing alloy even if the dehydrogenation process is performed under harsh conditions of high temperature and high vacuum for a long time, and high temperature may lead to a higher oxygen content, thereby reducing the absorption Hydrogen Absorption Performance of Hydrogen Components

Therefore, the hydrogen absorbing element prepared by this method can usually maintain high hydrogen absorbing performance at low temperature (room temperature) due to the intrinsic characteristics of the material, but at high temperature, such as the working temperature of high-temperature vacuum heat collecting tubes for thermal power generation (400°C) , due to incomplete dehydrogenation, the hydrogen absorption capacity is very poor, or even unable to absorb hydrogen

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