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Preparation method of nanocrystalline reinforced hard alloy

A cemented carbide and nanocrystalline technology, applied in the field of cemented carbide, can solve the problems of inability to obtain pure, many technological processes, and unfavorable industrial production.

Active Publication Date: 2021-04-27
ZIGONG CEMENTED CARBIDE CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In the above studies, most of them are based on Mo or Mo 2 The form of C is added to (Ti, W, Ta) C-based cermets or WC-Co / Ni alloys. When the addition amount is small, Mo or Mo 2 C is difficult to disperse evenly
In addition, at the sintering temperature, Mo or Mo 2 Most of C is dissolved in the binder phase, which prevents the dissolution-precipitation of WC and plays a role in refining the grains. Only a small part of it is dissolved in WC to form (WMo)C or (WMo) x C (third phase), therefore, with Mo or Mo 2 Adding the form of C to the alloy may not really play its due role.
However, the ammonium salt solution method is used to prepare the oxides of W and Mo, and then the oxide (WO 3 、MoO 3 ) to prepare (Mo, W)C powder by reduction-carbonization, there are many technological processes, and some processes pollute the environment, so it is not conducive to industrial production
[0009] U.S. Patent (No. 4,2547,809 (1981.3.24)) discloses a method for preparing a (WC-MoC) solid solution, which needs to crush the solid solution metal during the preparation process, and the powder particle size is difficult to guarantee; finally The obtained powder contains a certain amount of (Co / Ni / Fe), which is not a pure carbide phase, and pure (W, Mo)C powder cannot be obtained

Method used

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  • Preparation method of nanocrystalline reinforced hard alloy
  • Preparation method of nanocrystalline reinforced hard alloy
  • Preparation method of nanocrystalline reinforced hard alloy

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] A preparation method of nanocrystalline reinforced cemented carbide, comprising the following steps:

[0045]Step S1: Take the following raw materials in parts by weight:

[0046] Tungsten powder: 79.95~87.22 parts, Fsss particle size is 0.8~2.5μm;

[0047] Molybdenum powder: 4.54~9.09 parts, Fsss particle size is 0.8~2.5μm;

[0048] Chromium powder: 4.54~9.09 parts, Fsss particle size is 30~40μm;

[0049] Toner: 7.33~9.14 powder;

[0050] Chromium powder: 6-10 parts, passed through a 500-mesh sieve; spare;

[0051] Step S2: Mix the tungsten powder, molybdenum powder, chromium powder, and carbon powder in step S1 according to the ratio, grind, vacuum dry, wipe and sieve, hot press sintering, crushing, and ball milling to obtain (W, Mo, Cr)C powder;

[0052] Step S3: Mix (W, Mo, Cr)C powder and chromium powder according to the ratio, and obtain the mixture through ball milling, vacuum drying, wiping and sieving, and granulation;

[0053] Step S4: Pressing the mixed...

Embodiment 2

[0066] (1) Weigh the mass of each powder team member according to the mass percentage (take the total powder weight of 1000g as an example):

[0067]

[0068] (2) Add two groups of mixed material powder and WC-6% Co alloy balls (φ6mm) into the ball mill cylinder respectively, the ball-to-material ratio is 10:1, the amount of hexane added is 380ml / kg, the speed of the ball mill is 63 rpm, and the milling time is 24 ~30h. After ball milling, place the slurry in a vacuum oven at 70°C and dry for 2 hours, then cool the slurry to about 40°C and take it out to obtain a mixture.

[0069] (3) Put the mixture into a graphite mold for hot-press sintering, the sintering temperature is 2000°C, the pressure is 50KN, and the sintering time is 1h. Finally, the hot-pressed sample was broken and sieved through a -400 mesh (38 μm) sieve to obtain (W, Mo, Cr)C powder.

[0070] (4) Weigh the mass of each powder team member according to the mass percentage: (ingredient amount: 1000g)

[0071...

Embodiment 3

[0077] (1) Weigh the mass of each powder team member according to the mass ratio (take the total powder weight of 1000g as an example):

[0078]

[0079] (2) will WO 3 (commercially available, 3 (commercially available, 2 o 3 The powder (commercially available, <20 μm) is put into the ball mill barrel according to the weight ratio, the ball to material ratio is 10:1, the deionized water addition is 380ml / kg, the ball mill speed is 63 rpm, and the ball milling time is 24h. After ball milling, put the slurry in a drying oven at 70°C for 2 hours, and take it out after cooling down to about 40°C.

[0080] (3) Heat the dried mixed powder in a rotary furnace to 1000-1200°C for reduction, and the protective atmosphere is N 2 gas.

[0081] (4) Mix the mixed powder and C powder obtained by reduction in a mixer according to the ratio and mix for 3 hours. After mixing, put the mixed powder in a graphite boat and carbonize in an induction furnace for 2 hours. The carbonization tempe...

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Abstract

The invention relates to the technical field of hard alloys, and relates to a preparation method of a nanocrystalline reinforced hard alloy. The preparation method of the nanocrystalline reinforced hard alloy comprises the following steps of: mixing tungsten powder, molybdenum powder, chromium powder and carbon powder, and carrying out grinding, drying, wiping and screening, hot pressed sintering, crushing and ball milling on an obtained mixture to obtain (W, Mo, Cr) C powder; mixing (W, Mo, Cr) C powder and chromium powder, and carrying out ball milling, vacuum drying, wiping and screening and granulation on an obtained mixture to obtain a mixture; enabling the mixture to be subjected to compression molding, and sintering, cooling and discharging a product. According to the preparation method of the nanocrystalline reinforced hard alloy, molybdenum and chromium partially replace tungsten to prepare the hard alloy; the prepared (W, Mo, Cr) C-based hard alloy overcomes the defects of a traditional method for preparing a hard alloy containing molybdenum and chromium by adding metal or carbide; and the hardness, toughness and wear resistance of the alloy are improved.

Description

technical field [0001] The invention relates to the technical field of cemented carbide, in particular to a preparation method of nanocrystalline reinforced cemented carbide. Background technique [0002] Cemented carbide is a composite material prepared by powder metallurgy process with refractory metal carbides (such as WC, TiC, TaC, etc.) and bonding metals (such as Co, Ni, Fe, etc.) as the main components. Cemented carbide based on WC is widely used in the preparation of high-performance cutters, milling cutters and drill tools due to its high hardness and wear resistance, and is used in machining, metallurgy, mining, electronic communications, construction and other fields. With the continuous development of emerging industries such as natural gas, aerospace, and deep-sea oil, the demand for cemented carbide will continue to expand. [0003] The macroscopic properties of materials, such as the above-mentioned hardness, flexural strength, plasticity, fracture toughness,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C1/05C22C29/08
CPCC22C1/055C22C29/08C22C29/067
Inventor 时凯华昝秀颀董凯林曾伟顾金宝
Owner ZIGONG CEMENTED CARBIDE CORP