Method for preparing tungsten functional coating on tantalum surface at low temperature

Abstract

The invention discloses a method for preparing a tungsten functional coating on a tantalum surface at low temperature. The method comprises the following steps that S1, a base body is subjected to surface polishing treatment and comprises tantalum, a tantalum alloy or a combination of tantalum and the tantalum alloy; S2, the polished base body is embedded into an embedding permeating agent for reacting, wherein the embedding temperature ranges from 240 DEG C to 280 DEG C, the heat preservation time ranges from 1 h to 8 h, the embedding permeating agent comprises WCl6 powder, an activating agent and Al2O3 powder which are evenly dispersed, and the ratio of the WCl6 powder in the embedding permeating agent ranges from 30% to 50% by weight; and S3, after heat preservation is finished, the embedded base body is washed and subjected to vacuum drying. The embedding method is adopted, the base body and the embedding permeating agent generate a diffusion reaction at the temperature ranging from 240 DEG C to 280 DEG C, and therefore the tungsten functional coating is prepared. The base body and the tungsten functional coating are bonded well, the beneficial effect that the functional coating is uniform and compact is achieved, the coating can be obtained without a high temperature or pressurization method, the requirement for equipment is reduced, and the method is suitable for large-scale production.

Description

technical field [0001] The invention relates to the technical field of coating preparation, in particular to a method for preparing a tungsten functional coating on a tantalum surface at a low temperature. Background technique [0002] Tantalum has excellent properties such as high density, high melting point, corrosion resistance, excellent high temperature strength, good processability and weldability, and low plastic / brittle transition temperature, so it is widely used in various industries such as electronics, chemical industry, and weapons. However, tantalum metal is expensive and has poor corrosion resistance in certain atmospheres. Metal tungsten has a very high melting point, boiling point, extremely high strength, hardness, small electron work function and good chemical stability. The metal tungsten coating is prepared on the surface of the tantalum base material, which can be widely used as wear-resistant, corrosion-resistant and heat-shielding materials under hig...

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Problems solved by technology

[0003] Some researchers form a certain thickness of Ta-W diffusion layer by vacuum electron beam welding combined with hot isostatic pressing process, but the preparation temperature is high, the process is cumbersome, and there are problems of high cost and high energy consumption.

The preparation of pure tungsten coating by CVD method is to use hydrogen and tungsten halide or carbonyl gas as raw materials under normal or low pressure conditions, and finally obtain tungsten coating through mutual reduction reaction on the surface of the substrate under specific temperature conditions. The preparation of tungsten coating on parts by CVD process can directly obtain high-density, high-purity tungsten coating, but tantalum itself absorbs hydrogen and will become brittle and easy to break. This method is not suitable for the preparation of tungsten coating on the surface of tantalum.

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