A method and system for improving the performance of shield cutting tool cemented carbide

Abstract

The invention belongs to the technical field of alloys, and discloses a method and a system for improving the hard alloy performance of a shield cutter. The method comprises the following steps: aftergraphene is uniformly dispersed in an organic solvent in advance to form dispersion liquid, the graphene is mixed with coarse grain WC powder and CO powder, and then hard alloy of the shield cutter is prepared through the ball milling, drying and sintering process in sequence. The graphene is subjected to ultrasonic vibration dispersion in the organic solvent and is subjected to long-time ball milling with hard alloy raw material powder, so that a good mixing effect can be achieved, and thus the structure is uniform in the subsequent sintering process, and sintering defects are reduced. The excellent heat conduction performance and comprehensive mechanical properties of the grapheme are utilized, so that the heat conduction property of the hard alloy is enhanced and the mechanical property of the hard alloy is enhanced.

Description

Technical field [0001] The invention belongs to the technical field of alloys, and in particular relates to a method and a system for improving the performance of hard alloys of shield tools. Background technique [0002] Cemented carbide is a composite material composed of high hardness, high melting point metal carbides (WC, TiC) as the matrix and cobalt (Co), nickel (Ni) or molybdenum (Mo) as the binder phase. Cemented carbide has a unique combination of properties, that is, good wear resistance, high hardness, high compressive strength, high elastic modulus, strong impact resistance, high corrosion resistance, dimensional stability, etc. Shield cutter heads are generally made of coarse-grained WC-Co cemented carbide. [0003] Research on shield tool failure mechanism and tool temperature shows that the main failure modes of tools during shield construction are fracture and wear. Both failure phenomena are closely related to the temperature of the tool, such as the impact of WC...

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Problems solved by technology

[0007] The modification of cemented carbide in the prior art only improves the mechanical properties of cemented carbide through various technological means, while ignoring the specific conditions used. For shield cutting tools, the improvement of mechanical properties of strength and toughness is a key factor. On the one hand, the improvement of heat conduction and heat dissipation is a point that needs to be emphasized. When the temperature rises, the mechanical properties such as mechanical strength and hardness will drop sharply. However, many existing technologies are purely based on mechanical properties.

[0008] At the same time, the existing shield cutting tools are generally completed by hot pressing and sintering, and there will be a large number of defects. In the process of use, the defects will become the source of cracks. In the process of repeated use, the cyclic stress can easily cause it to crack, resulting in The fracture of the same casting is not enough, so that the hardness and wear resistance are reduced

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