Nonuniform cemented carbide for hot extruding hot die and method for preparing same

Abstract

The invention discloses a material for a hot heading die and a preparation process thereof. The compositions by weight percentage of the material are: 12 to 20 percent of cobalt, 3 to 10 percent of nickel, 50 to 70 percent of tungsten carbide with 20 to 25mu m, 10 to 30 percent of tungsten carbide with 1.0 to 1.5mu m. The preparation method for the material comprises the following steps: a step of mixing, during which the raw materials are taken in proportion and mixed evenly to obtain a mixture; a step of wet-grinding of the mixture, which is carried out inside a ball mill by using alcohol or acetone as the medium with a rotating speed of 36r / min and a grinding time of between 20 and 30 hours under the condition that the mixture is in accordance with the ratio of balls and the materials of 3-5 to 1, and the liquid-to-solid ratio of the mixture is 450-520ml / kg; a step of drying and press forming, and sintering in a vacuum furnace, thus the product is obtained. The invention uses the uneven structure theory of the hard alloy material, under the condition of certain content of cobalt in alloy, the fracture intensity and toughness of the alloy can be improved by reasonably collocating the proportion of coarse tungsten carbide powder and fine tungsten carbide powder, and inevitably the hardness and wear resistance can be improved thereafter. The different proportion between cobalt and nickel can obtain alloys with different impacting toughness and wear resistance. Furthermore, nickel powder is favorable to improve high-temperature oxidation resistance of the alloy.

Description

technical field [0001] The invention relates to a hard alloy and a preparation process thereof, in particular to a material for a high-strength and wear-resistant hot pier hot stamping die and a preparation process thereof. Background technique [0002] Because of its high strength and high hardness, cemented carbide is known as the tooth of industry and is a widely used tool material. However, the common technical problem of current cemented carbide products is how to organically combine the advantages of high strength and high hardness. When the alloy has high strength, it often has low hardness and poor wear resistance. When it has high hardness, it often has low strength. Poor toughness. How to realize the simultaneous realization of high strength and high hardness as much as possible to meet the special requirements of various construction machinery, rock drilling tools, and wear-resistant parts has always been the goal and direction of cemented carbide research. At p...

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Problems solved by technology

However, it is mainly aimed at cemented carbide used in the manufacture of snow shoveling flakes. Due to its low cobalt content of only 11-12%, the particle size of the main tungsten carbide powder is fine (9.01-13 μm), although it can meet the working state requirements of snow shoveling flakes. It also meets the strength requirements for making hot heading hot punching dies, but its impact toughness is poor, and its composition is pure tungsten carbide-cobalt, which is not resistant to high temperature and has weak oxidation resistance, so it is not suitable for making cemented carbide hot heading dies. further improvement