Toughened hard alloy and preparation method thereof

Abstract

The invention discloses a high-toughness toughened hard alloy which comprises 10%-30% of Co or Co and Ni serving as a binding phase, 0-1.5% of Cr3C2 serving as an inhibitor, and the balance of hard phase WC, wherein the hard phase consists of WC crystalline grains with coarse, medium and fine grain sizes, the grain size of coarse grains is 9-15 mu m, the grain size of medium grains is 4-7 mu m, the grain size of the fine grains is less than 2 mu m, and the mean grain size of the hard phase WC is 1.6-3.2 mu m. The preparation method of the toughened hard alloy comprises the following steps of: preparing materials including 10%-30% of cobalt powder or cobalt powder and nickel powder, 0-1.5% of chromium carbide powder, and the balance of tungsten carbide powder, wherein Fsss grain size of the coarse grains WC is 9.0-11.0 mu m, the coarse grains WC account for 20%-42% of the prepared powder, the Fsss grain size of the medium grains WC is 4.0-6.0 mu m, the medium grains account for 10%-25% of the prepared powder, the Fsss grain size of the fine grains WC is 1.0-2.0 mu m, and the fine grains account for 20%-40% of the prepared powder; grinding, wherein a liquid paraffin forming agent which accounts for 2% of the prepared materials is added, mixed with absolute ethyl alcohol in a liquid-solid ratio of 300 ml / kg-350ml / kg, wet-ground for 20-28 hours according to the condition that the ratio of grinding media to material is 4:1, and sprayed and dried to obtain mixed materials; pressing; vacuum-sintering and isostatic-pressing and sintering. According to the invention, the toughness is improved on the premise of ensuring the hardness of the alloy, so that the operation field is expanded, special requirements of a cold-heating and cold-punching mould and a holt-rolling hard alloy roller ring are satisfied, and the service life of the high-toughness toughened hard alloy is prolonged.

Description

[0001] technical field [0002] The invention relates to a toughened hard alloy and a preparation method thereof, especially suitable for cold-heading and cold-punching hard alloy molds in the hardware fastener industry requiring high wear resistance and high toughness, and hot-rolled hard alloy dies in the iron and steel industry. Toughened cemented carbide for cemented alloy roller rings and a preparation method thereof. Background technique [0003] Cemented carbide has the characteristics of high wear resistance and is widely used in industry. For example, with the rapid development of the fastener industry, cemented carbide with the advantages of high strength and high hardness has gradually replaced alloy tool steel in the field of cold heading dies. For use, it is mainly used for parts that directly contact the workpiece, and the hard alloy is pressed into the steel material jacket as a core mold, which is more wear-resistant and efficient, and its service life is inc...

AI Technical Summary

Problems solved by technology

The above-mentioned patents can improve the toughness of cemented carbide to a certain extent, but they are all aimed at cemented carbide in specific application fields. The performance shown is mainly suitable for cutting tools and mining cemented carbide, which is difficult to meet Performance requirements of wear-resistant parts such as roll rings and hard alloy cold heading dies

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