Method of producing powders of titanium-, zirconium- and hafnium-based alloys doped with elements ni, cu, ta, w, re, os, and ir. RU patent 2507034.

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy. It can be used in production of pyrotechnic fuses, as gas absorbers in vacuum tubes, lamps, vacuum hardware and gas cleaners. Oxide of basic element selected from Ni, Zr and Hf is mixed with alloying metal powder selected from Ni, Cu, Ta, W, Re, Os or Ir and with reducing agent powder. Produced mix is heated in kiln in atmosphere of argon to initiation of reduction reaction. Reaction product is leached, flushed and dried. Said oxide of basic element features mean particle size of 0.5-20 mcm, BET specific surface of 0.5-20 m²/g and minimum content of said oxide of 94 wt %.

EFFECT: powder with reproducible combustion time, specific surface and distribution of articles in sizes and time.

23 cl, 5 ex

The invention relates to a method for producing powders of alloys based on titanium, zirconium and hafnium, alloyed elements of Ni, Cu, Ta, W, Re, Os, Ir.

Powders of alloys based on titanium, zirconium and hafnium used in upon receipt of igniting devices, for example, in air cushions security and elements that slow the ignition, as in vacuum tubes, lamps, vacuum equipment and installations for gas cleaning. Due to the very high requirements to reliability of the above-mentioned products, for example, air bags, preferably produce alloy powder from batch to batch reproducibly with invariant properties, in particular, regarding the combustion time, ignition points, average particle size, particle size distribution and the oxidation potential. In addition, it is desirable that these properties can be set from the very beginning on specific values.

Production of powders of alloys can be performed by a combined method of recovery and doping. To do this, titanium oxide (TiO 2 ), zirconium (ZrO 2 ) or hafnium (HfO 2 ) is reduced along with powder alloying elements and a reducing agent, such as calcium and/or hydride calcium and/or magnesium and/or barium. Restoration carried out in a closed vessel with inert atmosphere. Oxide or reducing agent type, as a rule, in excess. After the restoration of the formed oxides reducers removed by leaching acid and the subsequent washing with water. The oxygen content of the received powder metal alloy is in this experience between 1 and 5%.

Alternatively, alloy powder based on Ti, Zr, Hf can be obtained from the corresponding metal by the hydrogenation and dehydrogenation (HDH-way). The corresponding metal and in this received fragile form it can be mechanically shredded in powder desired dispersion. To avoid damage due to the absorption of oxygen and nitrogen, for hydrogenation should be used hydrogen high degree of purity. Grinding hydrogenated metal to the desired size of particles must be in a clean protective atmosphere (inert gas, such as helium or argon. For the subsequent removal of hydrogen and education alloy powder of metal hydride - titanium, zirconium, hafnium or - and the corresponding subject powder of metal hydride or metal powder is decomposed in a vacuum at a high temperature and simultaneously .

The disadvantage of such an alloy powder is, among other things, that it does not show the playback time of burning, nor reproducible specific surface, nor reproduced particle size distribution and nor reproducible ignition points.

The objective of the invention is overcoming the shortcomings of the prior art.

Offers powder zirconium alloy, which has a burning time of 4/50 cm to 2000/50 cm and an ignition point from 160 degrees C to 400 deg C and, in addition, in some cases even higher. Burning time, expressed in 50 cm, is determined as follows: a verifiable substance first screened for clutter suppression of agglomerates in 2 screens with a width of grid cells 250 microns and 45 microns. If necessary, the sample being careful to brush moves. To determine the time of burning is used fine material, which was held 45 micron sieve. 15 g sample is served in free-flowing form on the following metal conduit, it shall exactly cardboard and excess is removed due to strip off. Metal conduit is equipped with two marks, which have a distance of 500 mm from each other. Before the beginning of the mark at first put the number of substances size of a pea, and ignite the burner. Using photographic imagery (with long exposures) is determined by the time necessary for the passage of the drift between the start and end markers. Result of the analysis of the burning time is specified in dimension [/50 cm] (seconds at 50 cm). Trough burning with the size of 3 mm x 2 mm is mounted in a strip steel with size 40 mm x 9.4 mm x 600 mm.

Flash point is determined as follows: 10 g to test substance is placed in a pre-heated by the so-called «block of ignition and measure the temperature at which self-ignition occurs. Unit ignition, consisting of an iron cube with a length of edges 70 mm with holes for material and thermocouple (20 mm and 8 mm in diameter, each hole 35 mm deep, the distance between the middle points of holes: 18 mm), after the introduction of a thermometer or thermocouple in the intended hole preheat a gas burner to a temperature of lying below, but close to the temperature of ignition. This point is determined by preliminary tests. Into the hole of the material preheated block of ignition impose on the edge of the trowel (10 g) subject to the study of powder material or hydride and block with the help of air-blowing the flame heated so long as the powder itself not flame. Consequent temperature is the point of ignition.

In addition, it is desirable that the powder metal alloy with a table of contents, at least 75 wt.-% metal or metal hydride, preferably, at least 88 weight,%, especially preferably at least 90 wt.-%, average particle diameter from 1 to 15 microns, the preferred distribution particle size d50 (measured with a laser scattering) from 1 to 20 mm, and the specific surface of 8 EG from 0.2 to 5 m 2 /year

The average diameter of the particles is determined on the «determinant of the size of particles with molecular sieve by Fisher» (hereinafter called the FSSS). Description this method of measurement is in the «Instructions Model 95 Sub-Sieve Sizer, Catalog no 14-311, Part №14579 (Rev. C)published 01-94 Fisher Scientific. In this link provides a detailed description of measurement.

Next problem is solved using the method of production of powders of alloys based on titanium, zirconium, hafnium or alloyed elements Mi, Cu, Ta, W, Re, Os, Ir, where oxide basic element mixed with reducing agent and subject metal and the mixture is heated in a furnace in argon atmosphere, if necessary, in an atmosphere of hydrogen (in this case, are formed hydrides metal), unless and until the start of the response and recovery, the reaction product leached and then washed and dried, and used oxide has an average particle size from 0.5 to 20 microns, preferably from 1 to 6 microns, the specific surface of BET from 0.5 to 20 m 2 /g, preferably from 1 to 12 m 2 /g and especially preferably from 1 to 8 m2 /g, and the minimum content of 94 weight,%, preferably 96 weight,%, and especially preferably 99 wt.-%.

The share of Fe and Al-impurities in the oxide is preferable, respectively, of <0.2 weight,%, especially preferably <0,08 weight,% (calculated, respectively, as oxide). The share of Si-impurities in the oxide is preferable, respectively, <1,5 weight,%, especially preferably <0.1 wt.-% (calculated as SiO 2 ). The share of Na impurities in oxide is preferably <0,05 weight,% (calculated as the Na 2 O). The share of P-impurities in the oxide is preferably of <0.2 wt.-% (calculated as P 2 O 5 ). Loss on ignition oxide at 1,000 degrees C (weight constant) is preferably <1 wt.-%, especially preferably of <0.5 wt.-%. Density tamping oxide according to EN ISO 787-11 (previously DIN 53194) is preferably from 800 to 1600 kg/m 3 . Oxide can be replaced before minority interest 15 wt.-% supplements MgO, CaO, Y 2 O 3 or CeO 2 .

It was found that when the target selection oxide raw substances with the described properties and the subsequent implementation process receive the products that have the time burning from 10 C/50 cm up to 3000 C/50 cm, ignition energy of 1 MJ up to 10 MJ, the average particle size from 1 up to 8 microns, the specific surface of BET from 0.2 to 5 m 2 /g, an ignition point from 160 degrees C to 400 deg C and in some cases exceed these values, thus, takes place repeatable particle size distribution. The combination of the average particle size and specific surface respectively in these areas oxide parent compound along with the specified minimum content of lead to the desired product.

As a reducing agent can preferably be used alkaline-earth metals and alkaline metals and their respective hydrides. Especially preferred are magnesium, calcium, calcium hydride and barium or some mixture of them. Preferably the restorer has the minimum content of 99 weight,%, especially preferably 99,5 wt.-%.

Depending on the share of the alloying funds are powdered pure powders of metal alloys, partially hydrogenated powders or powders of metal alloys alloys of metal hydrides. The higher hydrogen content and the higher the share of the alloying element product of the process, the more burning time, i.e. powder metal alloy burns slower, and the higher the point of ignition (powder metal alloy ignited at higher temperatures) and Vice versa.

Leaching of the reaction product is produced with the help of concentrated hydrochloric acid, which is used especially preferably in a small excess.

The invention is disclosed in more detail below on the basis of examples

Example 1 production of zirconium alloy powder/tungsten target composition 50/50 (Zr/W)

to 21.6 kg ZrO 2 (zirconium oxide powder, natural ) with the following characteristics: ZrO 2 +HfO 2 minutes 99,0%, HfO 2 from 1.0 to 2.0%, SiO 2 max 0.5%of TiO 2 max 0,3%, Fe 2 O 3 max 0,1%loss in discarded max.0,5%, and the average grain size (FSSS) from 4 to 6 microns, the share of the monoclinic crystal structure minutes 96%, specific surface area (BET) from 0.5 to 1.5 m 2 /g and

16,0 kg of powder metal tungsten with the following characteristics: W min. of 99.95% (without oxygen), oxygen maximum of 0.5%, Al 10 ppm, Cr max 80 ppm, Cu max 5 ppm, Fe max 100 parts per million, Mo max 100 parts per million, Na max 20 ppm, Ni max 100 ppm, Si max.30 parts per million, the average particle size (FSSS) 0.7 micrometers ±0.1 microns, power density from 0,150 up to 0,220 dm3 /kg, density with shaking from 0,570 to 740 g/l and

31,5 kg of calcium in the form of granulate with the following characteristics: Ca minutes 99,3%, Mg max 0,7%,

mixed together in a mixing tank 20 minutes in an argon atmosphere. The mixture is then introduced into the vessel. The vessel was placed in a microwave, which is then sealed and filled with argon to excess pressure 100 hPa. The reaction furnace was heated up within hours to a temperature of about 1250°C. as soon As reaction mass reached furnace temperature, began response and recovery:

ZrO 2 +2Ca+W→ZrW+2CaO.

After sixty minutes after switching on the heating furnace it again disconnected. After the temperature decreased to <50 C, the reaction mass is removed from the crucible concentrated hydrochloric acid. Received powder metal zirconium alloy/tungsten with the following characteristics:

96,1% Zr+Hf+W 2,2% Hf, 0,7% O, 0,06% H, 0,38% Mg, 0,076% Fe, 0,25 Al, 1.2 microns average grain size, particle size distribution, d50: 2.5 mkm, specific surface area: 0.5 m 2 /g, flash point: 220°C, the burning time of 55 C/50, see

Example 2 production of zirconium alloy powder/tungsten target composition of 50/50 (Zr/W)

16.2 kg ZrO 2 (zirconium oxide powder, natural) with the following characteristics: ZrO 2 +HfO 2 minutes 99,%, HfO 2 from 1.0 to 2.0%, SiO 2 max 0,2, TiO 2 Max. 0,25%, Fe 2 O 3 the maximum 0,02%loss in discarded 0,4%, average grain size (FSSS) from 3 to 5 microns, the share of the monoclinic crystal structure minutes 96%, specific surface area (BET) from 3,05 to 4.0 m2 /g and

12,0 kg of powder metal tungsten with the following characteristics: W min. of 99.95% (without oxygen), oxygen maximum of 0.5%, Al max 10 parts per million, Cr max 80 parts per million Cu max 5 parts per million, Fe max 100 parts per million, Mo max 100 parts per million, Na max 20 parts per million, Ni max 100 parts per million, Si max 30 parts per million, the average particle size (FSSS) 0.7 micrometers ±0.1 microns, power density from 150 to 0,220 dm3 /kg, density with shaking from 0,570 to 740 g/l and

7.2 kg of magnesium (magnesium in the form of chips) with the following characteristics: Mg minutes 99,5%, density with shaking maximum of 0.3 to 0.4 g/cm 3

as in example 1 made in the vessel in the kiln. The furnace was heated up to a temperature of about 1050°C. As soon as reaction mass reached furnace temperature, began response and recovery:

ZrO 2 +2Mg+W→ZrW+2MgO

Heating furnace disconnected after 20 minutes after the start of recovery. After the temperature decreased to <50 C, the reaction mass is removed from the crucible concentrated hydrochloric acid. Received powder metal zirconium alloy/tungsten with the following analyses:

97.9% of the Zr+Hf+W, 53% Zr, 0,9% Hf, 44% W, 0,083% Fe, 0,075% Al, 0,19% Mg, USD 0.087 Si, a 0.04%, H, average grain size of 1.2 MK, distribution size d50: 2,6 MC, flash point: 200 degrees C, the burning time with 44/50, see

Example 3 Manufacture of zirconium alloy powder/tungsten target composition 40/60 (Zr/W)

13,0 kg ZrO 2 (zirconium oxide powder) with the following characteristics: ZrO 2 +HfO 2 minutes 99,%, HfO 2 from 1.0 to 2.0%, SiO 2 max.0,2, TiO 2 max.0,25%, Fe 2 O 3 the maximum 0,02%loss in discarded max 0,4%, average grain size (FSSS) from 3 to 5 microns, the share of the monoclinic crystal structure minutes 96%, specific surface area (BET) from 3.0 to 4.0 m2 /g and

14.4 kg of powder metal W with the following characteristics: W min. of 99.95% (without oxygen), oxygen maximum of 0.5%, Al max 10 parts per million, Cr max 80 parts per million Cu max 5 parts per million, Fe .100 parts per million, Mo max 100 parts per million, Na max 20 parts per million, Ni max 100 ppm, Si max.30 parts per million, the average particle size (FSSS) 0.7 micrometers ±0.1 microns, power density from 0,150 up to 0,220 dm3 /kg, density with shaking from 0,570 to 740 g/l and

5.8 kg Mg (magnesium in the form of chips) with the following characteristics: Mg minutes 99,5%, density with shaking maximum of 0.3 to 0.4 g/cm 3 similar to example 1 made in the vessel in the kiln. The furnace was heated up to a temperature of about 1050°C. as soon As reaction mass reached furnace temperature, began response and recovery:

ZrO 2 +2Mg+W→ZrW+2MgO

Heating furnace disconnected after 20 minutes after the start of recovery.

After the temperature decreased to <50 C, the reaction mass is removed from the crucible concentrated hydrochloric acid. Received powder metal zirconium alloy/tungsten with the following characteristics:

97.8% of Zr+Hf+W, 41% Zr, 0,78% Hf, 56% W, 0.028% of Fe, 0,090% Al, 0,14% Mg, 0,097% Si, 0,14% H, average grain size is 1.2 microns, the distribution of particle size d50:of 2.2 microns, flash point: 200 degrees C, the burning time 37/50, see

Example 4 Fabrication of zirconium alloy powder/Nigel, the target composition 70/30 (Zr/Ni)

36 kg ZrO 2 (zirconium oxide powder) with the following characteristics: ZrO 2 +HfO 2 minutes 98,5%, HfO 2 from 1.0 to 2.0%, SiO 2 max.0,6%, TiO 2 max 0,15%, Fe 2 O 3 Max. 0,05%, Na 2 O Max. up to 0.3%loss in discarded max 0.5%, and the average grain size (FSSS) from 1.7 to 2.3 mkm, and

26,4 kg of calcium (the calcium in the form of chips) with the following characteristics: Ca minutes 98,5%, Mg maximum of 0.5%,

2.0 kg Mg (magnesium in the form of chips) with the following characteristics: Mg minutes 99,5%, density with shaking maximum of 0.3 to 0.4 g/cm 3 mixed together in a mixing tank 20 minutes in an argon atmosphere. The mixture is then introduced into the vessel. The vessel was placed in a microwave, which is then sealed and filled with argon to excess pressure 100 hPa.

The reaction furnace was heated up within hours to a temperature of about 1250°C. as soon As reaction mass reached furnace temperature, began response and recovery:

ZrO 2 +2Ca/Mg→Zr+2CaO/MgO.

reaction mass is removed from the crucible concentrated hydrochloric acid.

Received powder zirconium alloy/Nickel with the following characteristics:

98,3% Zr+Ni (incl. Hf, Zr 70,2%, Ni 28,1%, Hf 1,4%, Ca 0,09%, Fe 0,046%, Al 0.13%for the S 0,003%, the burning time is 210 C/50 cm, flash point: 40 C, average grain size (FSSS):4,2 microns.

Example 5 powder Fabrication alloy titanium/copper target composition 75/25 (Ti/Cu)

1.2 kg TiH 2 (powdered titanium hydride) with the following characteristics: TiH 2 minutes 98,8%, H min 3,8%, N max 0,3%, Mg Max. 0,04%, Fe Max. 0,09%, Cl Max. 0,06%, Ni maximum of 0.05%, Si max 0,15%, C Max. 0.03%and the average grain size (FSSS) from 3 to 6 microns and 10.0 kg Cu (copper powder form) with the following characteristics: Cu minutes 99,3%, density with shaking from 2.6 to 2.8 kg/DM 3 , sieve analysis with 325 mesh from 50 to 65 microns, sieve analysis at 150 mesh from 10 to 20 mm

mixed together in a mixing tank 20 minutes in an argon atmosphere. Then the mixture when loading 5 kg inflicted on the leaf plate. Leaf plates placed in the microwave, which is then sealed and filled with argon to excess pressure 100 hPa. Then produced pumping out of the oven. The reaction microwave heated in several stages for 6 hours at a vacuum to a maximum temperature of approximately 800 C the Reaction proceeded in the following way:

TiH 2 +Cu→TiCu+H 2

After about 4 hours, depending on the pressure in the furnace) heating furnace disconnected. After the furnace is cooled to room temperature, mass removed and agglomerates smashed. Received alloy Ti/Cu with the following analysis: 72,4% Ti, 25,3% Cu, 0,02% H, 0,05% Al, 0,02% Fe, 0.005% of Mg, Cd<0,001%, Zn<0,002%, Hg<0,0002%, particle size distribution, d50: 17,7%, average grain size (FSSS) of 9.4 microns.

1. The method of obtaining powder alloy on the basis of the group item 4 of the Periodic system of elements selected from titanium (Ti), zirconium (Zr) and hafnium (Hf)alloyed with Nickel (Ni), copper (cu), tantalum (TA), tungsten (W), in (Re), osmium (Os) or iridium (Ir), including mixing oxide powder basic element having an average particle size from 0.5 to 20 mm in specific surface BET 0.5-20 m 2 /g and contains at least 94% wt. oxide, metal powders alloy metal and powder reducing agent, heating of the mixture in the oven in argon atmosphere before the start of the reduction reaction, leaching of the reaction product, rinsing and drying.

2. The method according to claim 1, characterized in that the alloy metal powder has a grain size 0.5 to 15 microns.

3. The method according to claim 1, characterized in that the alloy metal powder has the minimum content of 99.5% wt. metal.

4. The method according to claim 1, characterized in that the share of Si, Fe and Al-impurities in the alloying elements is <0.1 wt.%.

5. The method according to claim 1, wherein the mixture is heated in a furnace from 800 to 1400°C.

6. The method according to claim 1, wherein the used oxide powder is the average size of grains from 1 to 6 microns.

7. The method according to claim 1, wherein the used oxide powder has a specific surface by BET from 1 up to 12 m 2 /year

8. The method according to claim 7, wherein the used oxide powder has a specific surface by BET from 1 up to 8 m 2 /year

9. The method according to claim 1, wherein the used oxide powder has the minimum content of 96% wt. oxide.

10. The method of claim 9, wherein the used oxide powder has the minimum content of 99% wt. oxide.

11. The method according to claim 1, characterized in that the share of Fe and Al-impurities in the oxide is, respectively, of <0.2 wt.% in terms of oxide.

12. The method according to claim 11, wherein the share of Fe and Al-impurities in oxide is <0.1 wt.% in terms of oxide.

13. The method according to claim 1, characterized in that the share of Si-impurities in the oxide is <1.5 weight.% in terms of SiO 2 .

14. The method according to item 13, wherein the share of SiO 2 impurities in the oxide is <0,3% wt. in terms of SiO 2 .

15. The method according to claim 1, characterized in that the share of Na impurities in oxide is <0,05 weight.% in terms of Na 2 o

16. The method according to claim 1, characterized in that the share of R-impurities in the oxide is <0.2% W / W in terms of P2O5 .

17. The method according to claim 1, characterized in that the loss in discarded oxide at 1,000 degrees C (constant weight) is <1 wt.%.

18. The method according to claim 1, characterized in that the density of tamping oxide according to EN ISO 787-11 is from 800 to 1600 kg/m 3 .

19. The method according to claim 1, wherein the mixture also contains additives MgO, CaO, Y 2 About 3 or SEO 2 to 15 wt.% from the share of oxide.

20. The method according to claim 1, characterized in that as a reductant use alkaline earth metals, and/or alkaline metals, and/or metal hydrides.

21. The method according to claim 20 wherein as a reductant use of Mg, Ca, CaH 2 or VA.

22. The method according to claim 1, characterized in that the restorer has the minimum content of 99% wt. reducing agent.

23. The method according to claim 1-22, wherein the leaching of the reaction product spend hydrochloric acid.