CN102389971A - Preparation method of La-doped W-Cu composite powder - Google Patents
Preparation method of La-doped W-Cu composite powder Download PDFInfo
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- CN102389971A CN102389971A CN2011103449875A CN201110344987A CN102389971A CN 102389971 A CN102389971 A CN 102389971A CN 2011103449875 A CN2011103449875 A CN 2011103449875A CN 201110344987 A CN201110344987 A CN 201110344987A CN 102389971 A CN102389971 A CN 102389971A
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Abstract
The invention discloses a preparation method of La-doped W-Cu composite powder, which comprises the preparation of activated tungsten powder and the preparation of composite powder, wherein the preparation of the activated tungsten powder comprises the following steps: carrying out ultrasonic activation on tungsten powder in an activation liquid for 30-40 minutes, washing with de-ionized water after the activation is completed, and drying to obtain the activated tungsten powder. The preparation of the composite powder comprises the following steps: adding the activated tungsten powder into a chemical deposition solution, wherein the dosage of the tungsten powder is 30-50g/L; regulating with sodium hydroxide until the pH value is 12.0-13.0; carrying out ultrasonic deposition and coating at normal temperature for 40-80 minutes; and standing for 2-3 hours, filtering, washing, and drying to obtain the composite powder. The obtained powder has high component homogenizing degree, avoids the tungsten and copper oxide reduction process of the conventional preparation method, and has the advantages of simple treatment process and low preparation cost. Besides, the invention greatly improves the flowability of the composite powder in the sintering process, and carries out direct sintering at low temperature; and the relative density of sintering samples can be up to 98.7% or above.
Description
One, technical field
The present invention relates to the powder body material preparation field, specifically a kind of preparation method of La doping W-Cu composite powder.
Two, background technology
Powder metallurgy W-Cu composite is because of having good physics, mechanical property; Stronger anti-ablative, thermal shock resistance, and excellent thermal control and microwave absorbing property etc. have obtained using widely in fields such as national defense industry, Aero-Space, electronic information and machinings; In national economy, occupy an important position; Therefore, tungsten-bast alloy has received the great attention of countries in the world all the time, has become comparatively one of active research field of material supply section educational circles.In these are used, often require the W-Cu material to have higher densification degree to improve its performance level.Just from present main direction of studying; Ultra-fine/nanometerization is the main direction of W-Cu composite research with the gradient-structure functional material, and the preparation key of full densification, high performance aplitic texture W-Cu composite is obtaining of ultra-fine/nanostructured W-Cu composite granule.At present, research both at home and abroad reports that the technology of preparing of more ultra-fine W-Cu powder has mechanical alloying, spraying-seasoning, colloidal sol-spray-drying-co-reducing process, freeze-dried method, sol-gel process, homogeneous precipitation method, mechanical thermochemical method, oxide co-reducing process etc.For example, Central South University adopts colloidal sol-spray-drying-co-reducing process to prepare ultra-fine/nanometer W-10%Cu composite powder, and its alloy can obtain the good comprehensive performances reason, and to be behind sintering, to obtain higher density and institutional framework evenly tiny.HeFei University of Technology adopts homogeneous precipitation method, obtains Cu
2WO
4(OH)
2/ CuWO
42H
2The O predecessor after calcining, reduction, finally obtains copper content and is 30% ultra-fine W-Cu composite powder.Human sol-gel processes such as Raghunathan have prepared the nanocrystalline W base composite powder of multiple size at 10～30nm, like composite powders such as W-Mo, W-Cu, W-Ni and WC-Co.Said method partly exists cost higher, and the processing time is longer, is difficult to produce in batches, and there is easy introducing impurity in part preparation method, oxygen content is higher and powder is prone to phenomenons such as agglomerating.
Three, summary of the invention
The present invention aims to provide a kind of preparation method of La doping W-Cu composite powder, and technical problem to be solved is to make composite powder reach higher sintered density at lower sintering temperature, and reduces the agglomerating phenomenon of composite powder.
Technical solution problem of the present invention adopts following technical scheme:
The preparation method's of La doping W-Cu composite powder of the present invention characteristics are: comprise the preparation of activation tungsten powder and the preparation of composite powder;
The preparation of said activation tungsten powder is that tungsten powder was placed the activating solution ultrasonic activation 30-40 minute, spends deionised water after activation is accomplished and obtains the activation tungsten powder in 180-200 ℃ of dry 1-3 hour; The particle diameter of said tungsten powder is not more than 1 micron;
Said activating solution is the aqueous solution of hydrofluoric acid, ammonium fluoride and nitric acid, and the concentration of hydrofluoric acid is 30-60ml/L in the said activating solution, in the hydrofluoric acid solution of mass concentration 40%; The concentration of ammonium fluoride is 8-10g/L; The concentration of nitric acid is 50-80ml/L, in the salpeter solution of mass concentration 65%;
The preparation of said composite powder is that the activation tungsten powder is added in the chemical deposition solution; The addition of tungsten powder is 30-50g/L; With NaOH adjust pH 12.0-13.0, ultrasonic deposition coated 40-80 minute under the normal temperature, left standstill filtration after 2-3 hour, washing and drying and obtained composite powder;
Said chemical deposition solution is the aqueous solution of copper sulphate, lanthanum chloride, formaldehyde, disodium ethylene diamine tetraacetate and natrium citricum; The concentration of copper sulphate is 6-25g/L in the said chemical deposition solution; The concentration of lanthanum chloride is 0.8-2.6g/L; The concentration of formaldehyde is 5-20mL/L, and the concentration of disodium ethylene diamine tetraacetate is 10-20g/L, and the concentration of natrium citricum is 20-30g/L.
The supersonic frequency of said ultrasonic activation is 40KHz, and power is 300-400W.
The supersonic frequency that said ultrasonic deposition coats is 40KHz, and power is 300-400W.
Said drying is prior to 120-160 ℃ of dry 0.5-1, again in 160-200 ℃ of dry 3-6 hour.
The composite powder of preparation is obtained pressed compact with the compacting of the unit pressure of 100MPa, said pressed compact is placed tube type resistance furnace, at H
2Under the protection, 1150-1300 ℃ of sintering 90-120min promptly gets La doping W-Cu composite.
The present invention coats superfine rare-earth La doped with Cu layer through normal temperature ultrasonic wave assistant chemical sedimentation then through tungsten powder being carried out the auxiliary activation processing of normal temperature ultrasonic wave on the tungsten powder surface, finally obtain the equally distributed La doping of composition W-Cu composite powder.Prepared powder has good sintering activity, direct lower temperature sintering, and sintering appearance relative density reaches more than 98.7%, has promptly reached very high densification degree.
Compared with present technology, beneficial effect of the present invention is embodied in:
Compare with the preparation method of present ultra-fine W-Cu composite granule, normal temperature ultrasonic wave assistant chemical sedimentation prepares superfine rare-earth La doping W-Cu composite powder, and its copper tungsten composition is controlled, to satisfy the performance requirement of W-Cu sill under the different condition; The homogenising degree of gained powder composition of the present invention is high; Particularly need not conventional preparation method's tungsten copper oxide reduction process, treatment process is simpler, and preparation cost is lower; The prepared rare earth La doped with Cu of the present invention coats W surface recombination powder; Cu and La atom ratio content in whole composite granule reaches 15-25% and 0.5-2% respectively; Greatly improved the flowability of composite granule sintering process; Direct lower temperature sintering, sintering appearance relative density reaches more than 98.7%.
Four, the specific embodiment
Below in conjunction with specific embodiment the present invention is described further.
Embodiment 1:
1, the preparation of activation tungsten powder
Particle diameter was placed the activating solution ultrasonic activation 30 minutes less than 1 micron tungsten powder, and supersonic frequency is 40KHz, and power is 300-400W, and activation spends deionised water three times and obtained the activation tungsten powder in 1 hour in 200 ℃ of dryings after accomplishing;
Said activating solution is the aqueous solution of hydrofluoric acid, ammonium fluoride and nitric acid, and the concentration of hydrofluoric acid is 60ml/L in the said activating solution, in the hydrofluoric acid solution of mass concentration 40%; The concentration of ammonium fluoride is 9g/L; The concentration of nitric acid is 60ml/L, in the salpeter solution of mass concentration 65%;
2, the preparation of composite powder
The activation tungsten powder is added in the chemical deposition solution, and the addition of tungsten powder is 30g/L, with sodium hydroxide solution adjust pH 13.0; Ultrasonic deposition coated 60 minutes under the normal temperature; Supersonic frequency is 40KHz, and power is 300-400W, leaves standstill after 2 hours to filter, wash; Prior to 120 ℃ of dryings 1 hour, obtained composite powder in 3 hours in 200 ℃ of dryings again;
Said chemical deposition solution is the aqueous solution of copper sulphate, lanthanum chloride, formaldehyde, disodium ethylene diamine tetraacetate and natrium citricum; The concentration of copper sulphate is 6g/L in the said chemical deposition solution; The concentration of lanthanum chloride is 2g/L; The concentration of formaldehyde is 10mL/L, and the concentration of disodium ethylene diamine tetraacetate is 10g/L, and the concentration of natrium citricum is 20g/L;
3, compacting sintering
The composite powder of present embodiment preparation is obtained pressed compact with the unit pressure press forming of 100MPa, place tube type resistance furnace then, at H
2Protection obtains La doping W-Cu composite sintered body down in 1300 ℃ of sintering temperature 90min.
La doping W-Cu composite powder homogenization of composition, the powder purity of present embodiment preparation are high, the powder lumping phenomenon do not occur.Prepared rare earth La doped with Cu coats W surface recombination powder, and Cu and La atom ratio content in whole composite granule reaches 15% and 1% respectively, and prepared pressed compact is under 1300 ℃ of sintering temperature 90min conditions, and sintering appearance relative density reaches 99.1%.
Embodiment 2:
1, the preparation of activation tungsten powder
Particle diameter was placed the activating solution ultrasonic activation 40 minutes less than 1 micron tungsten powder, and supersonic frequency is 40KHz, and power is 300-400W, and activation spends deionised water three times and obtained the activation tungsten powder in 3 hours in 180 ℃ of dryings after accomplishing;
Said activating solution is the aqueous solution of hydrofluoric acid, ammonium fluoride and nitric acid, and the concentration of hydrofluoric acid is 30ml/L in the said activating solution, in the hydrofluoric acid solution of mass concentration 40%; The concentration of ammonium fluoride is 8g/L; The concentration of nitric acid is 80ml/L, in the salpeter solution of mass concentration 65%;
2, the preparation of composite powder
The activation tungsten powder is added in the chemical deposition solution, and the addition of tungsten powder is 50g/L, with sodium hydroxide solution adjust pH 13.0; Ultrasonic deposition coated 40 minutes under the normal temperature; Supersonic frequency is 40KHz, and power is 300-400W, leaves standstill after 3 hours to filter, wash; Prior to 160 ℃ of dryings 0.5 hour, obtained composite powder in 6 hours in 160 ℃ of dryings again;
Said chemical deposition solution is the aqueous solution of copper sulphate, lanthanum chloride, formaldehyde, disodium ethylene diamine tetraacetate and natrium citricum; The concentration of copper sulphate is 25g/L in the said chemical deposition solution; The concentration of lanthanum chloride is 0.8g/L; The concentration of formaldehyde is 20mL/L, and the concentration of disodium ethylene diamine tetraacetate is 15g/L, and the concentration of natrium citricum is 30g/L;
3, compacting sintering
The composite powder of present embodiment preparation is obtained pressed compact with the unit pressure press forming of 100MPa, place tube type resistance furnace then, at H
2Protection obtains La doping W-Cu composite sintered body down in 1150 ℃ of sintering temperature 120min.
La doping W-Cu composite powder homogenization of composition, the powder purity of present embodiment preparation are high, the powder lumping phenomenon do not occur.Prepared rare earth La doped with Cu coats W surface recombination powder, and Cu and La atom ratio content in whole composite granule reaches 25% and 0.5% respectively, and prepared pressed compact is under 1150 ℃ of sintering temperature 120min conditions, and sintering appearance relative density reaches 98.7%.
Embodiment 3:
1, the preparation of activation tungsten powder
Particle diameter was placed the activating solution ultrasonic activation 35 minutes less than 1 micron tungsten powder, and supersonic frequency is 40KHz, and power is 300-400W, and activation spends deionised water three times and obtained the activation tungsten powder in 2 hours in 190 ℃ of dryings after accomplishing;
Said activating solution is the aqueous solution of hydrofluoric acid, ammonium fluoride and nitric acid, and the concentration of hydrofluoric acid is 50ml/L in the said activating solution, in the hydrofluoric acid solution of mass concentration 40%; The concentration of ammonium fluoride is 10g/L; The concentration of nitric acid is 50ml/L, in the salpeter solution of mass concentration 65%;
2, the preparation of composite powder
The activation tungsten powder is added in the chemical deposition solution, and the addition of tungsten powder is 40g/L, with sodium hydroxide solution adjust pH 12.0; Ultrasonic deposition coated 80 minutes under the normal temperature; Supersonic frequency is 40KHz, and power is 300-400W, leaves standstill after 2 hours to filter, wash; Prior to 160 ℃ of dryings 0.5 hour, obtained composite powder in 5 hours in 180 ℃ of dryings again;
Said chemical deposition solution is the aqueous solution of copper sulphate, lanthanum chloride, formaldehyde, disodium ethylene diamine tetraacetate and natrium citricum; The concentration of copper sulphate is 15g/L in the said chemical deposition solution; The concentration of lanthanum chloride is 2.6g/L; The concentration of formaldehyde is 5mL/L, and the concentration of disodium ethylene diamine tetraacetate is 20g/L, and the concentration of natrium citricum is 25g/L;
3, compacting sintering
The composite powder of present embodiment preparation is obtained pressed compact with the unit pressure press forming of 100MPa, place tube type resistance furnace then, at H
2Protection obtains La doping W-Cu composite sintered body down in 1250 ℃ of sintering temperature 110min.
La doping W-Cu composite powder homogenization of composition, the powder purity of present embodiment preparation are high, the powder lumping phenomenon do not occur.Prepared rare earth La doped with Cu coats W surface recombination powder, and Cu and La atom ratio content in whole composite granule reaches 19% and 2% respectively, and prepared pressed compact is under 1250 ℃ of sintering temperature 110min conditions, and sintering appearance relative density reaches 99.2%.
Claims (4)
1. the preparation method of a La doping W-Cu composite powder is characterized in that: comprise the preparation of activation tungsten powder and the preparation of composite powder;
The preparation of said activation tungsten powder is that tungsten powder was placed the activating solution ultrasonic activation 30-40 minute, spends deionised water after activation is accomplished and obtains the activation tungsten powder in 180-200 ℃ of dry 1-3 hour; The particle diameter of said tungsten powder is not more than 1 micron;
Said activating solution is the aqueous solution of hydrofluoric acid, ammonium fluoride and nitric acid, and the concentration of hydrofluoric acid is 30-60ml/L in the said activating solution, in the hydrofluoric acid solution of mass concentration 40%; The concentration of ammonium fluoride is 8-10g/L; The concentration of nitric acid is 50-80ml/L, in the salpeter solution of mass concentration 65%;
The preparation of said composite powder is that the activation tungsten powder is added in the chemical deposition solution; The addition of tungsten powder is 30-50g/L; With NaOH adjust pH 12.0-13.0, ultrasonic deposition coated 40-80 minute under the normal temperature, left standstill filtration after 2-3 hour, washing and drying and obtained composite powder;
Said chemical deposition solution is the aqueous solution of copper sulphate, lanthanum chloride, formaldehyde, disodium ethylene diamine tetraacetate and natrium citricum; The concentration of copper sulphate is 6-25g/L in the said chemical deposition solution; The concentration of lanthanum chloride is 0.8-2.6g/L; The concentration of formaldehyde is 5-20ml/L, and the concentration of disodium ethylene diamine tetraacetate is 10-20g/L, and the concentration of natrium citricum is 20-30g/L.
2. preparation method according to claim 1 is characterized in that: the supersonic frequency of said ultrasonic activation is 40KHz, and power is 300-400W.
3. preparation method according to claim 1 is characterized in that: the supersonic frequency that said ultrasonic deposition coats is 40KHz, and power is 300-400W.
4. preparation method according to claim 1 is characterized in that: said drying is prior to 120-160 ℃ of dry 0.5-1 hour, again in 160-200 ℃ of dry 3-6 hour.
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| CN103736992A (en) * | 2013-11-22 | 2014-04-23 | 合肥工业大学 | Preparation method of nano TiC/W composite powder of core-shell structure |
| CN103894600A (en) * | 2014-04-22 | 2014-07-02 | 合肥工业大学 | High-strength and high-conductivity W-Cu/Lu2O3 composite material and preparation method thereof |
| CN110605385A (en) * | 2019-10-29 | 2019-12-24 | 广东银纳科技有限公司 | Preparation method of tungsten-based micro-nano composite powder and tungsten-based micro-nano composite powder |
| CN112570724A (en) * | 2020-12-11 | 2021-03-30 | 江西理工大学 | Preparation method of rare earth tungsten copper composite powder |
| CN115178740A (en) * | 2022-08-22 | 2022-10-14 | 合肥工业大学 | Tungsten-copper functionally gradient material and preparation method thereof |
| CN115845853A (en) * | 2022-12-16 | 2023-03-28 | 东华工程科技股份有限公司 | Preparation method of double-shell hollow porous carbon nanotube supported cobalt single-atom catalyst |
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| CN103736992A (en) * | 2013-11-22 | 2014-04-23 | 合肥工业大学 | Preparation method of nano TiC/W composite powder of core-shell structure |
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| CN115178740B (en) * | 2022-08-22 | 2024-01-16 | 合肥工业大学 | Tungsten-copper functionally graded material and preparation method thereof |
| CN115845853A (en) * | 2022-12-16 | 2023-03-28 | 东华工程科技股份有限公司 | Preparation method of double-shell hollow porous carbon nanotube supported cobalt single-atom catalyst |
| CN115845853B (en) * | 2022-12-16 | 2024-04-19 | 东华工程科技股份有限公司 | Preparation method of double-shell hollow porous carbon nanotube supported cobalt monoatomic catalyst |
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