Omnipotent Tungsten Carbide Thermal Spraying Material Preparation

Hot spray welding (coating) technology has made rapid progress. There have been high energy plasma spraying, vacuum plasma spraying, supersonic flame spraying, explosive spraying and other new technologies, which can improve the performance of the coating more than the existing oxygen one acetylene flame spraying. Moreover, the hard alloy hot spray welding (coating) powder is convenient to make, no matter which kind of technology is used, the raw material of the spray can not be carbonized.

Some scholars have developed a tungsten carbide thermal spraying material, which is suitable for oxygen one acetylene flame spraying and supersonic flame spraying, plasma spraying, explosive spraying and other hot spray welding (coating) to make mechanical surface harden and strengthen, and chemical composition is stable.

The WC powder with 6.14% C content and an average particle size of 4 μm, a cobalt powder with an average size of 2 μm, 6.2% of the total carbon, and 20g tantalum with an average particle size of 30 μm, ball milling for 16 hours, pressed into a lump of φ60 * 8mm, sintered for 1 hours under the vacuum of 20Pa and the temperature of 1420°C. The physical properties of the cemented carbide are as follows: the density is 14.21 g/cm³, the hardness HRA is 87.2, the coercive magnetic force is 7.4KA/m, the bending strength is 1948N/mm².

The above process is to weigh the tungsten carbide, Fe, Co and Ni of hard phase, which is more than one metal and additive in Ni. It is mixed or milled by dry mixing or ball milling. The mixture is pressed into pieces, blocks or pelleting to be sintered at high temperature. The gas is crushed into powder, sieved and graded into a product. It is sintered at high temperature in a vacuum and a specific gas. The specific gas is one of the reducing gases such as inert gas and hydrogen and ammonia, the sintering temperature is 1250~1500°C and the sintering time is 30~60 minutes. Crushing and grading with crusher can make the powder particle size reach below 100 μm and the powder particle size is even.

The particle size distribution of the tungsten carbide based hard alloy powder is narrow, the chemical composition is stable, the fluidity is good and the deposition rate is high. It is suitable for the oxygen one acetylene flame spraying and suitable for the supersonic flame spraying, plasma spraying, explosive spraying and other hot spray welding (coating) methods, the thickness of the coating is formed. Uniform, fine and high hardness, coating resistance to wear and corrosion.

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