Method for quickly synthesizing Ti3SiC2 submicron powder

Abstract

The invention provides a method for quickly synthesizing Ti3SiC2 submicron powder. The method comprises the following steps of: 1) proportioning Ti powder, SiC power and TiC powder serving as raw materials and Al powder serving as a synthesis accelerant in a molar ratio of Ti: SiC: TiC: Al of (4-4.05): (2-2.1): (1-1.15): (0.2-0.25); 2) performing dry milling and wet milling on the materials; 3) screening and cleaning the ball-milled materials to obtain mixed suspension, filtering the mixed suspension, removing the filtrate, and performing vacuum drying to obtain pretreated mixed powder; 4) pressing the mixed powder into blocks; 5) putting the blocks into a vacuum furnace, heating the furnace to the temperature of between 1,330 and 1,340 DEG C at the temperature rise rate of 15 to 20 DEG Cper minute, performing treatment under the vacuum degree of 1*10<-3> to 1*10<-2>Pa, preserving the heat for 3 to 4 minutes, and preparing Ti3SiC2 powder; and 6) performing dry milling on the preparedTi3SiC2 powder, and screening the ball-milled Ti3SiC2 powder to obtain the submicron Ti3SiC2 powder. The method has simple process, is easy to control, realizes large-scale production, and has low production cost; and the prepared Ti3SiC2 powder has high purity.

Description

technical field [0001] The present invention relates to a kind of submicron Ti 3 SiC 2 A rapid synthetic preparation method for the powder. Background technique [0002] Recently, material scientists are constantly researching new high-performance ceramic materials, which not only have the characteristics of high temperature resistance, oxidation resistance and high strength of ceramic materials, but also have good electrical conductivity, thermal conductivity, plasticity and processability of metal materials. specialty. Although metal-ceramic composites solve many defects of ceramics to a certain extent, the combination of metal and ceramics has poor oxidation resistance and high temperature resistance, and is easy to be brittle. Since 1980, due to the rapid development of reinforcing agents such as fibers, whiskers, and carbon nanotubes and the demand for aviation high thrust-to-weight ratio engines, ceramic matrix composites have become a research hotspot. Although th...

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Problems solved by technology

[0006] (1) Among the commonly used synthetic raw materials, such as Ti / Si / C, Ti / TiC / Si, the direct reaction of Ti and C or Si during the reaction process will lead to a sudden concentration of heat, and the sintering temperature is too high will make some Si powder is too late to react and is lost by evaporation, which will lead to changes in the molar ratio of raw materials, which is not conducive to Ti 3 SiC 2 Synthesis of high-purity phases, usually TiC, SiC and Ti 5 Si 3 The existence of impurity phases such as; and the evaporation of Si powder may also cause damage to the components of the sintering furnace, resulting in an increase in synthesis costs

[0007] (2) The price of Ti powder and TiC powder in raw materials is relatively high, and the cost of raw materials will affect the Ti powder to a certain extent. 3 SiC 2 Large-scale production of high-purity powders

[0008] (3) Ti 3 SiC 2 Both block and powder synthesis methods have certain defects

However, the price of the raw material Ti in the 3Ti / Si / 2C formula is high, which is not conducive to reducing production costs; at the same time, the evaporation loss of Si can easily lead to the formation of impurities such as TiC

The 2Ti / Si / TiC formula can replace part of the Ti metal raw material with TiC with a lower price, which is beneficial to reduce the cost, but the presence of Si in the raw material leads to the introduction of impurities such as TiC on the one hand, and on the other hand, Si with a low melting point It is easy to volatilize to the sintered components (such as heating element) of the sintered equipment at low temperature, thereby corroding the equipment and accelerating the aging of the equipment

Utilize lower priced TiC or TiH 2 Part of Ti powder can be replaced by Al powder, which can greatly reduce the production cost. The presence of Al also greatly reduces the sintering temperature and improves the Ti powder. 3 SiC 2 The formation speed, but there is Si powder in the raw materials of the two patents, the existence of Si powder will volatilize during the heating process, which not only causes the molar ratio of raw materials to change, thereby affecting the purity of the product; and the volatilized gaseous Si is easy to pollute the sintering original, making its lifespan reduced

The synthesis temperature reaches 1550°C, which is relatively high, which is not conducive to reducing production costs

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