A kind of in-situ preparation method of surface self-lubricating cemented carbide

Abstract

The invention discloses an in-situ preparation method of a hard alloy achieving surface self-lubrication. The in-situ preparation method of the hard alloy achieving surface self-lubrication is characterized in that forming-agent-free hard alloy green bodies with the porosity being 25%-40% are formed under the condition that the temperature of 550-750 DEG C is kept for 2-4 h; core / shell structure powder with Al2O3 covering TiH2 and nanometer graphite with the thickness granularity being 30-50 nm are mixed at the weight percentage ratio of 1:2 so as to prepare a carburizing medium containing hydrogen; the green bodies are embedded into the carburizing medium containing hydrogen and are compacted at the pressure of 5-15 MPa; and finally, liquid-phase sintering is conducted, and in-situ preparation of the hard alloy achieving surface self-lubrication is achieved based on carbon migration. The in-situ preparation method of the hard alloy achieving surface self-lubrication overcomes the problems that in the prior art, grains grow severely, the carburizing time is long and efficiency is low, and in-situ preparation of the hard alloy achieving surface self-lubrication is achieved 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 self-lubricating hard alloy, which belongs to the field of hard materials. Background technique

[0002] Cemented carbide, known as the "teeth" of industry, has a history of more than 80 years since it came out in 1923. For more than 80 years, as a high-efficiency tool material and structural material, cemented carbide has continuously expanded its application fields, played an important role in promoting the world's industrial development and scientific and technological progress, and its market capacity has also continued to expand. In order to improve its friction and wear performance, carburizing treatment can be carried out on the surface to make the surface rich in graphite phase, so as to obtain a good anti-friction effect.

[0003] CN104404283A relates to a method for directly adding refractory metals to prepare gradient hard ...

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