New Preparation Process of Tungsten Carbide-Titanium Carbide Solid Solution

The new preparation process of tungsten carbide-titanium carbide solid solution tungsten carbide-titanium carbide solid solution is a kind of compound carbide with high melting point, high hardness, high wear resistance, excellent anti-adhesion, oxidation resistance and wear resistance. It is widely used in cemented carbide products for mechanical processing. It is found that when carbide mixtures are added, it is difficult to control the carbon content because of the solid solution reaction during the sintering process. Therefore, carbide solid solution is usually added to cemented carbides in the production of cemented carbides.

The traditional method of preparing tungsten carbide-titanium carbide solid solution is to use industrial titanium dioxide and WC as raw materials, carbon black as reducing agent, mix with ball mill, and react in graphite tube electric furnace at the temperature of 2000-2300 ℃. The preparation method has the following shortcomings: first, the ball mill has low ball milling efficiency, mainly mixing effect on raw materials and little crushing effect. Second, the high reaction temperature makes the sintering growth of the prepared tungsten carbide-titanium carbide solid solution obvious.

In order to improve the shortcomings of the traditional process, a new preparation method of tungsten carbide-titanium carbide solid solution has been developed by some researchers.

(1)Titanium dioxide powder, WC powder, ultrafine tungsten powder and granulated carbon black are proportioned according to the following mass percentage: Titanium dioxide 45.7%, WC 32.8%, carbon black 20.5%, ultrafine tungsten powder 1%.

(2)The prepared material was added to 400 mL alcohol and milled in a wet mill for 6 hours. The speed of the mill was 36 r/min.

(3)The wet-grinded material is dried and put into a graphite boat, and hydrogen is supplied to the intermediate frequency furnace. The flow rate of hydrogen is 0.2 m³/h. The material is sintered at 1900 ℃ for 6 hours.

(4) Tungsten carbide-titanium carbide solid solution with particle size of 1.85 um was prepared by crushing the reacted material with ball mill for 4 hours and passing through 100 mesh sieve.

Using the high activity of ultrafine tungsten powder, the carbonization and solid solution reaction can be carried out more quickly, the reaction temperature can be controlled at 1600-1900 ℃, the reaction temperature can be reduced greatly, the energy can be saved, and the tungsten carbide-titanium carbide solid solution with low oxygen and nitrogen content can be produced by one reaction, which improves the production efficiency. The finished product is finer, more uniform and has better particle size distribution than that produced by traditional methods.

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