Synthetic method of high-purity ultrafine ZrC-SiC composite powders

一种复合粉体、合成方法的技术，应用在化学仪器和方法、碳化合物、无机化学等方向，能够解决热分解产物坚硬、准确配制困难、易发泡和流失等问题，达到来源方便、容易研磨粉碎细化、比例准确不变的效果

Active Publication Date: 2016-03-23
SHANDONG ULSTREETCARING FINE CERAMICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this kind of resin is expensive, usually insoluble in water, and requires the use of organic solvents, and its thermal decomposition products are very hard and difficult to crush; there are also reports on the use of sucrose as a carbon source to synthesize carbide powder, but experiments show that sucrose The middle C component is very easy to foam and lose during the thermal decomposition process. Its theoretical C content is 42wt%, but the C yield after thermal decomposition at 400°C is only less than 20wt%, and the C yield will vary under different conditions. changes, which brings great difficulties to the accurate formulation of Zr:C ratio
However, there has been no report on the one-step synthesis of highly uniformly mixed high-purity ultrafine ZrC-SiC composite powders.

Method used

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  • Synthetic method of high-purity ultrafine ZrC-SiC composite powders
  • Synthetic method of high-purity ultrafine ZrC-SiC composite powders

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] Synthesis of 50mol% ZrC-50mol% SiC composite powder

[0050] Accurately weigh 200g of zirconium silicate micropowder and 249g of sucrose, i.e. (Zr+Si): C=1:4, add to 150ml of deionized water, and add 3ml of ammonium polyacrylate dispersant, mix and grind in a roller mill for 12h to obtain Water-based slurry with good suspension stability; add 30g of acrylamide monomer and 1.5g of methylene bisacrylamide cross-linking agent, continue to mix and grind for 1 hour, pour it into a beaker, add dropwise 10% ammonium persulfate aqueous solution to trigger Add 2ml of 50% concentration of tetramethylethylenediamine solution dropwise, then add 1.5ml of catalyst in aqueous solution of tetramethylethylenediamine, stir evenly, let it stand for about 3min, and then the in-situ gel solidifies; pound the wet gel into pieces and put it in a 100°C oven Dry in medium for 16 hours, then heat up to 220°C for pretreatment for 8 hours; put the pretreated jelly block into a graphite crucible, k...

Embodiment 2

[0052] Synthesis of 75mol% ZrC-25mol% SiC Composite Powder

[0053] Accurately weigh 1833g zirconium silicate micropowder, 2464g zirconia micropowder, 3993g sucrose, (Zr:Si:C=0.75:0.25:3.5), add to 2000ml deionized water, and add 60ml ammonium polyacrylate dispersant, in the roller mill The water-based slurry with good suspension stability was obtained after medium mixing for 12 hours. Then add 200g of acrylamide monomer, 15g of N',N'-methylene bisacrylamide cross-linking agent, continue to mix and grind for 1 hour, pour it into an enamel tank, add 15% concentration of oxidation-reduction agent aqueous solution 15ml (ammonium persulfate : Ammonium sulfite = 1.5: 1), stir evenly and let stand for about 5 minutes, the water-based slurry gel solidifies in situ; the wet gel is cut into thin slices ≤ 3mm thick with a zirconia ceramic knife, and heated at 120°C Dry in an oven for 12 hours, then raise the temperature to 180°C for pretreatment for 24 hours; put it into a graphite cru...

Embodiment 3

[0056] Synthesis of 90mol% SiC-10mol% ZrC Composite Powder

[0057] Accurately weigh 183.3g zirconium silicate micropowder, 1200g glucose, add 1600g silica sol (concentration is 30wt%, i.e. SiO 2 The content is 480g, at this time Si:Zr:C=0.9:0.1:4), mixed in a roller mill for 8h to obtain a water-based slurry with good suspension stability. Then add 150g of acrylamide monomer, 6g of N',N'-methylenebisacrylamide cross-linking agent, continue to mix and grind for 2 hours, then discharge the material into the enamel pot, add azobisisobutylamidine hydrochloride with a concentration of 5% 10ml of saline solution, stir evenly, and keep warm in a 70°C water bath for about 5 minutes, and the water-based slurry will gel and solidify in situ. Break the wet gel into pieces, dry it in an oven at 100°C for 16 hours, then raise the temperature to 200°C for 10 hours, put it into a graphite crucible, and heat it to 1450°C for 2 hours under the protection of argon in a carbon tube heating fur...

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Abstract

The present invention belongs to the field of inorganic nonmetallic materials, and relates to a synthetic method of high-purity ultrafine ZrC-SiC composite powders. The synthetic method comprises the following steps: taking only zirconium silicate or zirconium silicate added with one or both of zirconium oxide or colloidal silica as a zirconium source and a silicon source material, taking sucrose or glucose as a carbon source material, and taking acrylamide monomer and a methylene-bisacrylamide cross-linking agent as a gel material to prepare the high purity ultrafine ZrC-SiC composite powders. The ZrC-SiC composite powders synthesized by the synthetic method provided by the present invention are mixed very uniformly and are quite high in purity, and the purity is greater than or equal to 99%, and the particle size d is less than or equal to 50 [mu]m. An aqueous pulp containing acrylamide monomer and the methylene bisacrylamide cross-linking agent is subjected to in-situ gel curing, C can closely coat the surfaces of solid phase powder particles very uniformly, so that segregation of raw materials in dehydration and reaction processes is avoided, and carbothermal reduction synthesis reaction can be carried out fully.

Description

technical field [0001] The invention belongs to the field of inorganic non-metallic materials, and relates to a method for synthesizing high-purity ultrafine ZrC-SiC composite powder. Background technique [0002] ZrC is a refractory metal carbide with high melting point (3530°C), high hardness (25.5GPa), high thermal conductivity and electrical conductivity similar to metal, high chemical stability and good radiation resistance. High-purity ultra-fine ZrC powder is widely used in ultra-high temperature resistant structural ceramics and anti-oxidation coatings of aerospace vehicles, nuclear industry thermoelectric radiator coatings and nuclear fuel particle coatings, ultra-high temperature refractory materials and other fields. In order to reduce the sintering temperature of ZrC ceramics and coatings, improve their fracture toughness and oxidation resistance, or to obtain some other special properties, sometimes it is necessary to add a certain amount of SiC powder and mix i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/56C04B35/565C04B35/626
CPCC04B35/624C01B32/907C01B32/914C01P2006/80C04B35/5622C04B35/565C04B35/6265C04B2235/3248C04B2235/3418C04B2235/3826C04B2235/3839C04B2235/5445C04B2235/72C04B2235/80
Inventor 陈大明蒋丹宇
Owner SHANDONG ULSTREETCARING FINE CERAMICS
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