Preparation method for iron-coated ceramic composite powder of core-shell structure

Abstract

The invention discloses a preparation method for iron-coated ceramic composite powder of a core-shell structure. The preparing method comprises the following steps that (1) ceramic particles are selected to be placed into a fluidized bed, mixed fluidization gas of hydrogen and argon passes through a fluidized bed, and the ceramic particles are in the fluidized state; (2) the ceramic particles in the fluidized state are heated; (3) an iron precursor is heated, and the argon is used as carrier gas to carry iron precursor steam to enter a fluidized bed reaction section zone; (4) a chemical vapordeposition reaction is carried out in the fluidized bed reaction section zone; and (5) after the reaction is finished, argon shield cooling is carried out and the product temperature reaches to the room temperature, and the iron-coated ceramic composite powder of the core-shell structure is obtained. The composite powder has the advantages that the product is pure, impurities and pollution are avoided, the bonding force between an iron-coated layer and a ceramic base is high, iron is evenly distributed to the surface of the powder, and the content can be controlled. The preparation method foriron-coated ceramic composite powder has the advantages that the technological process is simple, the reaction condition is gentle, and large-scale and continuous production is facilitated.

Description

technical field [0001] The invention belongs to the field of metal-ceramic composite materials, and in particular relates to a method for preparing a core-shell structure iron-coated ceramic composite powder material. Background technique [0002] Due to its excellent strength, thermal hardness, chemical stability, anti-wear and oxidation resistance and many other advantages, ceramic materials have broad application prospects in many aspects such as cutting, forming and anti-wear coating. However, due to the poor toughness of ceramic materials and the difficulty of direct compression molding, etc., the modification of ceramic materials by adding metal elements has become an important means at present. Studies have shown (Alireza Jam, Leila Nikzad, Mansour Razavi, TiC-based cermet prepared by high-energy ball-milling and reactive spark plasma sintering, Ceramics International, 2017, 43:2448-2455), due to the excellent fracture toughness and phase Capacitive, non-toxic, wide ...

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Problems solved by technology

At present, the main methods for preparing iron-reinforced metal-ceramic composites include mechanical alloying, casting, and self-propagating high-temperature synthesis, but these methods have the following problems: mechanical alloying is difficult to achieve uniform mixing of iron and ceramics, and due to The ceramic material has high hardness and serious wear, which is easy to cause pollution to the product; the casting method is easy to form pores and inclusions, and the interface is prone to reaction, which requires high wettability between the surface of the iron and the ceramic substrate, and due to the presence of iron and ceramic materials The difference in density may easily cause segregation; the composite powder prepared by the self-propagating high-temperature synthesis method has problems such as uneven distribution of elements, easy agglomeration, and high energy consumption.

The traditional electroless plating and electroplating methods are complicated in process, and the ceramic particles need to undergo complicated pretreatment processes such as roughening, activation, and sensitization, which are expensive; and it is easy to introduce impurity salts; the agitation uniformity changes during the enlarged production process, resulting in coating Uneven or even a large amount of self-nucleating metals; the reaction process produces a large amount of toxic and harmful waste liquid, which is easy to cause environmental pollution

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