Niobium Carbide-Aluminum Nitride Composite Powder Based On Aluminum Niobium Carbide And Preparation Method And Process Thereof.

wallpapers Industry 2020-11-13
Background technique:
 
Niobium carbide (NbC) is a metal carbide with high hardness (greater than 235GPa), high toughness, high Young's modulus, high melting point (about 3610°C) and good corrosion resistance. It can be used as composite ceramics and hard Additives in alloys, raw materials in turbine rotors, and coatings for cutting and milling tools. Aluminum nitride (AlN) has the characteristics of high thermal conductivity, high resistivity, low dielectric constant, low dielectric loss, excellent mechanical properties, non-toxicity, high temperature resistance and corrosion resistance. It is used in electronics, machinery and composite materials. The field has a wide range of applications.
 
At present, the methods for preparing composite materials containing NbC phase include: E.M.J.A Pallone and others use Al, Nb2O5, C and Al2O3 as raw materials, and high-energy grinding for 3 to 5 hours to prepare Al2O3-NbC composite powder. However, this method has incomplete reaction, low product purity and high energy consumption for long-term grinding.
LiHongmei et al. used CaCl2-NaCl molten salt as electrolyte, SnO2, Nb2O5, and C as raw materials, electrochemical reduction method, electrolysis at 900 ℃ and 3V voltage for 4-6 hours to prepare NbC-Sn composite powder. However, the technology is complicated, the reaction by-products need to be processed later, the equipment requirements are high, and the production cycle is long.
 
Liu Jianren and others used laser cladding technology to prepare a wear-resistant coating on the surface of 12Cr1MoV alloy steel. The coating has TiC/NbC particles generated in situ as a composite reinforcement phase. However, the TiC/NbC distribution in the coating prepared by this technology is uneven and cracks are prone to occur.

 
Technical realization elements:
 
The present invention aims to overcome the defects of the prior art, and aims to provide a method for preparing Nb2AlC-based NbC-AlN composite powder with short production cycle, simple process and low cost, and the Nb2AlC-based NbC-AlN composite powder prepared by the method The powder has high purity and uniform particle distribution.
 
In order to achieve the above objective, the technical solution adopted by the present invention is:
 
Place the Nb2AlC powder in a graphite crucible, and then put the graphite crucible into an atmosphere furnace; in a nitrogen atmosphere, heat the graphite crucible to 1200-1600°C at a heating rate of 1 to 5°C/min, Keep holding for 1 to 3 hours and cool to room temperature naturally to prepare NbC-AlN composite powder based on Nb2AlC.
 
The purity of the Nb2AlC powder is greater than or equal to 98.0 wt%, the particle size of the Nb2AlC powder is less than or equal to 0.05 mm, and the purity of nitrogen is greater than or equal to 98.5%.

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