A kind of in-situ preparation method of surface carburizing cemented carbide

Abstract

The invention discloses an in-situ preparation method of surface carburized hard alloy, which is characterized in that it first heats the temperature at 550-700°C for 1-2 hours to form a hard alloy body containing carbide-forming elements; then wraps Al2O3 TiH2-coated core / shell structure powder, multi-walled carbon nanotubes with an outer diameter of less than 8nm, a length of less than 30μm and a specific surface area greater than 350m2 / g, and BaCO3 are mixed at a weight percentage of 2:3:1 to prepare hydrogen-containing carburizing medium; then embed the green body in a hydrogen-containing carburizing medium and compact it under a pressure of 5-15 MPa; finally, carry out liquid phase sintering to prepare a surface carburized cemented carbide. The invention overcomes the problems of serious crystal grain growth, long carburizing time and low efficiency in the existing technology, and realizes in-situ preparation of surface carburized hard alloy in the sintering process.

Description

technical field

[0001] The invention relates to a preparation method of hard alloy, in particular to an in-situ preparation method of surface carburized hard alloy, which belongs to the field of hard materials. Background technique

[0002] The composition and performance of traditional hard alloys are basically the same from the outside to the inside, which limits the application of traditional hard alloy materials. This internal contradiction existing in cemented carbide can be resolved by adopting new material preparation technology and changing the distribution characteristics of cemented carbide microstructure. Through surface carburizing, its surface can be used to realize self-lubrication and improve its surface friction and wear performance.

[0003] CN104493161A discloses a method for carburizing cemented carbide in a vacuum sintering furnace, comprising the following steps: a. putting each cemented carbide decarburized product into a bag containing a carburizing m...

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