Hard alloy taking nickel-aluminum intermetallic compound Ni3Al as binding phase and preparation method thereof

Abstract

The invention discloses a hard alloy which takes a nickel-aluminum intermetallic compound, namely Ni3Al as a binding phase, wherein the B accounts for 0.0025 to 0.0252 percent based on the weight of the hard alloy; and the binding phase accounts for 10 to 40 percent based on the volume of the hard alloy. The preparation of the hard alloy sequentially comprises the following steps of: uniformly mixing 2.09 to 28.94 weight percent of nickel powder, aluminum powder and the balance of carbide powder according to an ingredient proportion of Ni50Al; putting into a graphite container to ensure that the paving thickness is less than or equal to 50mm, heating to the temperature of between 660 and 1,300 DEG C at a temperature increase speed of less than or equal to 2 DEG C / min in non-oxidizing atmosphere, keeping the temperature for over 1 hour, and naturally cooling to obtain a mixture of carbide and NiAl; grinding, crushing, and sieving to obtain mixed powder, of which the particle size is less than 120mu m, of carbide and Ni3Al; performing deoxidation pretreatment; according to an ingredient proportion of Ni24Al, adding 3.01 to 30.06 weight percent of Ni powder and 0.025 to 0.0252 weight percent of B powder into the mixed powder of the carbide and the NiAl which are subjected to deoxidation pretreatment, and performing wet grinding and mixing for 18 to 36 hours to obtain a wet-ground mixture; treating the wet-ground mixture to form a green compact; and sintering in a low-pressure liquid phase at the temperature of between 1,350 and 1,550 DEG C to obtain the hard alloy which takes the Ni3Al as the binding phase. The hard alloy has the advantages of uniform microstructures, high densification, high strength, high wear resistance, and excellent high-temperature oxidization resistance and corrosion resistance; and the process is simple, and manufacturing cost is low.

Description

technical field [0001] The invention relates to a cemented carbide material and a preparation method thereof, in particular to a toughened and reinforced cemented carbide with carbide as the matrix and nickel-aluminum intermetallic compound as the binder phase prepared by powder metallurgy technology and its preparation method. method. Background technique [0002] Tungsten carbide cemented carbide is widely used as cutting tools, mining tools and wear-resistant parts due to its high strength, high hardness, high wear resistance and high red hardness. The existing tungsten carbide cemented carbide materials are mainly composed of matrix tungsten carbide and binder phase cobalt metal. Due to the good wettability of cobalt to tungsten carbide, the comprehensive mechanical properties at room temperature are good, but cobalt is a strategic resource, the price is relatively expensive, and its high-temperature wear resistance, high-temperature oxidation resistance and corrosion r...

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Problems solved by technology

[0007] The Ni used in the above hot pressing method and liquid phase sintering method 3 Al pre-alloyed powder is generally prepared by smelting Ni and Al according to a certain composition ratio and then atomized into powder by inert gas. The prepared pre-alloyed powder is often relatively coarse, which is easy to cause uneven microstructure in the alloy and produce holes. Affect mechanical properties

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