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A preparation method of high-performance wc-co cemented carbide with plate-like crystal structure

A technology of cemented carbide and crystal structure, which is applied in the field of preparation of high-performance WC-Co cemented carbide with plate-like crystal structure, can solve the problems of small proportion of plate-like grains, difficult sintering and densification of alloys, and poor grain orientation. , to achieve the effect of excellent comprehensive performance

Active Publication Date: 2018-06-29
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Currently, by adding other substances (such as TiC, Y 2 o 3 , plate-shaped WC seed crystals, etc.) combined with high temperature and high-pressure sintering to induce the WC grains to develop into plates, cemented carbides containing plate-shaped WC grains can be prepared, but these preparation methods generally have the number of plate-shaped WC grains and The size is difficult to control, the proportion of plate-shaped grains is small or the grain orientation is poor, and special sintering equipment is required, so that the comprehensive properties such as hardness and toughness of cemented carbide cannot be effectively improved, and the application is limited.
Using W powder and graphite with plate-like morphology as raw materials, chemically synthesizing plate-like WC grains is an effective way to prepare plate-shaped cemented carbide, but the alloy is difficult to sinter and densify.

Method used

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  • A preparation method of high-performance wc-co cemented carbide with plate-like crystal structure
  • A preparation method of high-performance wc-co cemented carbide with plate-like crystal structure
  • A preparation method of high-performance wc-co cemented carbide with plate-like crystal structure

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Experimental program
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Effect test

Embodiment 1

[0031]Weigh 24 grams of ammonium metatungstate, 27 grams of anhydrous glucose, 50 grams of cobalt nitrate and 2.0 grams of chromium nitrate, dissolve them in alcohol, and after fully mixing, add 70 grams of flaky W powder induced by ball milling, and mix them by ball milling After uniformity (ball milling time 2h, ball-to-material ratio 10:1), the precursor mixed powder for reduction was prepared by ball milling after vacuum heating and evaporation. Put the precursor powder into a five-zone temperature-controlled continuous four-tube atmosphere muffle reduction furnace for in-situ carbon-assisted hydrogen reduction. The reduction temperature is 560-600-640-700-760°C, the reduction time is 300 minutes, and the excess hydrogen flow rate is large. Passivation treatment with inert gas such as nitrogen before being released from the furnace. The obtained composite powder, after testing and re-adjusting the carbon ingredients, added 2.5% by weight of powdered paraffin and an appropr...

Embodiment 2

[0033] Weigh 20 grams of ammonium metatungstate, 27 grams of anhydrous glucose, 50 grams of cobalt nitrate and 2.0 grams of chromium nitrate, dissolve them in alcohol, and after fully mixing, add 73 grams of flaky W powder induced by ball milling, and mix them by ball milling After uniformity (ball milling time 2h, ball-to-material ratio 10:1), the precursor mixed powder for reduction was prepared by ball milling after vacuum heating and evaporation. Put the precursor powder into a five-zone temperature-controlled continuous four-tube atmosphere muffle reduction furnace for in-situ carbon-assisted hydrogen reduction. The reduction temperature is 600-640-680-760-820°C, the reduction time is 300 minutes, and the excess hydrogen flow rate is large. Passivation treatment with inert gas such as nitrogen before being released from the furnace. The obtained composite powder, after testing and re-adjusting the carbon ingredients, added 2.5% by weight of powdered paraffin and an approp...

Embodiment 3

[0035] Weigh 17 grams of ammonium metatungstate, 27 grams of anhydrous glucose, 50 grams of cobalt nitrate and 2.0 grams of chromium nitrate, dissolve them in alcohol, and after fully mixing, add 75 grams of flaky W powder induced by ball milling, and mix them by ball milling After uniformity (ball milling time 2h, ball-to-material ratio 10:1), the precursor mixed powder for reduction was prepared by ball milling after vacuum heating and evaporation. Put the precursor powder into a five-zone temperature-controlled continuous four-tube atmosphere muffle reduction furnace for in-situ carbon-assisted hydrogen reduction. The reduction temperature is 560-600-640-700-760°C, the reduction time is 300 minutes, and the excess hydrogen flow rate is large. Passivation treatment with inert gas such as nitrogen before being released from the furnace. The obtained composite powder, after testing and re-adjusting the carbon ingredients, added 2.5% by weight of powdered paraffin and an approp...

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Abstract

The invention relates to a preparation method of high-performance WC-Co cemented carbide of a plate-like grain structure and belongs to the field of cemented carbide materials and preparation thereof. The preparation method includes subjecting dispersed and evenly distributed W / Co / C composite powder to carbon regulation, wet grinding, drying, compression molding and carbonizing sintering by one time at 1380-1460 DEG C so as to obtain the high-performance WC-Co cemented carbide of the plate-like grain structure, wherein the W / Co / C composite powder contains W nanopowder and W plate-like grains. The preparation method has the advantages that the novel high-performance WC-Co cemented carbide of the full-density plate-like grain structure, which is almost fully-densified and excellent in overall performance, can be obtained within short sintering time at a low temperature and has a promising industrialized application prospect in the machining fields such as turning, drilling and milling and in the aspects of being used as a coated cemented carbide substrate and the like.

Description

technical field [0001] The invention relates to a preparation method of a high-performance WC-Co hard alloy with a plate crystal structure, belonging to the field of hard alloy materials and preparation. Background technique [0002] The hard phase WC in WC-Co cemented carbide is an anisotropic crystal belonging to the hexagonal crystal system. If the bottom (001) surface with higher hardness grows preferentially, it is usually in the shape of a triangular or polygonal prism. The grains will transform into plate-shaped WC grains, which will improve the overall hardness of the WC-Co cemented carbide and at the same time help to improve the fracture toughness of the alloy. Generally, the fracture toughness KIC of low-cobalt two-phase WC-Co cemented carbide mainly depends on the volume fraction of γ phase and its mean free path and composition, and its micro-cracks are at the weaker WC / WC crystal interface and WC / Co phase interface. Formation and propagation or fracture throug...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C29/08C22C1/05B22F3/10B22F3/02B22F9/26
CPCB22F3/02B22F3/1039B22F9/26B22F2998/10C22C1/055C22C29/005C22C29/08
Inventor 雷纯鹏刘文胜马运柱刘阳
Owner CENT SOUTH UNIV