EP1543172B1 - Purification of metal particles by heat processing - Google Patents
Purification of metal particles by heat processing Download PDFInfo
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- EP1543172B1 EP1543172B1 EP03753690A EP03753690A EP1543172B1 EP 1543172 B1 EP1543172 B1 EP 1543172B1 EP 03753690 A EP03753690 A EP 03753690A EP 03753690 A EP03753690 A EP 03753690A EP 1543172 B1 EP1543172 B1 EP 1543172B1
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- Prior art keywords
- particles
- metal
- impurities
- pellets
- heat source
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- 238000000746 purification Methods 0.000 title claims abstract description 14
- 239000002923 metal particle Substances 0.000 title claims description 10
- 238000000034 method Methods 0.000 claims abstract description 104
- 229910052751 metal Inorganic materials 0.000 claims abstract description 79
- 239000002184 metal Substances 0.000 claims abstract description 79
- 239000002245 particle Substances 0.000 claims abstract description 65
- 239000012535 impurity Substances 0.000 claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 claims abstract description 31
- 238000002844 melting Methods 0.000 claims abstract description 20
- 230000008018 melting Effects 0.000 claims abstract description 20
- 238000001816 cooling Methods 0.000 claims abstract description 16
- 238000004663 powder metallurgy Methods 0.000 claims abstract description 12
- 238000011946 reduction process Methods 0.000 claims abstract description 8
- 238000009834 vaporization Methods 0.000 claims abstract description 6
- 239000012798 spherical particle Substances 0.000 claims abstract description 5
- 239000000843 powder Substances 0.000 claims description 44
- 239000008188 pellet Substances 0.000 claims description 35
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 26
- 239000010936 titanium Substances 0.000 claims description 24
- 229910052719 titanium Inorganic materials 0.000 claims description 22
- 229910001092 metal group alloy Inorganic materials 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 14
- 229910045601 alloy Inorganic materials 0.000 claims description 13
- 239000000956 alloy Substances 0.000 claims description 13
- 239000008187 granular material Substances 0.000 claims description 13
- 239000007787 solid Substances 0.000 claims description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 4
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 4
- 229910052791 calcium Inorganic materials 0.000 claims description 4
- 239000011575 calcium Substances 0.000 claims description 4
- 239000001110 calcium chloride Substances 0.000 claims description 4
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 4
- 238000010894 electron beam technology Methods 0.000 claims description 4
- 229910052749 magnesium Inorganic materials 0.000 claims description 4
- 239000011777 magnesium Substances 0.000 claims description 4
- 238000009835 boiling Methods 0.000 claims description 3
- 238000004320 controlled atmosphere Methods 0.000 claims description 3
- 230000006698 induction Effects 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- 238000010891 electric arc Methods 0.000 claims 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 11
- 229910001069 Ti alloy Inorganic materials 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 150000002739 metals Chemical class 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 229910044991 metal oxide Inorganic materials 0.000 description 6
- 150000004706 metal oxides Chemical class 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 239000000356 contaminant Substances 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 4
- 230000008021 deposition Effects 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- -1 for example Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 3
- 239000004408 titanium dioxide Substances 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 238000013019 agitation Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000005868 electrolysis reaction Methods 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 239000001307 helium Substances 0.000 description 2
- 229910052734 helium Inorganic materials 0.000 description 2
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 238000005339 levitation Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 150000002736 metal compounds Chemical class 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910002065 alloy metal Inorganic materials 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005660 chlorination reaction Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000001513 hot isostatic pressing Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/1295—Refining, melting, remelting, working up of titanium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/129—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining metallic titanium from titanium compounds by dissociation, e.g. thermic dissociation of titanium tetraiodide, or by electrolysis or with the use of an electric arc
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
- C22B9/14—Refining in the solid state
Definitions
- This invention relates to a method for the purification of metal particles, for example, metal powders and other finely sized metal samples, and, in particular, to ones that have been produced by the process of electrochemical reduction of metal compounds.
- the invention is particularly suited to the purification of titanium powder formed from the electrolytic reduction of titanium oxide TiO 2 .
- WO 99/64638 describes methods for the electrolytic reduction (or "electro-reduction") of metal compounds. Certain embodiments of those methods involve the electrolysis of metal oxides or other compounds in a cell containing a liquid (fused salt) electrolyte and an anode, the metal oxide forming or contacting the cathode. Conditions are controlled so as to bring about the selective dissolution of the oxygen of the cathode in preference to deposition of the metal cation of the fused electrolyte. The metals extracted by such methods, however, often require further purification.
- GB2359564 is directed to improved methods for carrying out such processes, particularly to produce powdered titanium, and some of those methods are summarised below:-
- Sintered granules or powders of metal oxide can be used as the feedstock for the electrolysis described in the above referenced method, as long as appropriate conditions are present.
- powdered titanium dioxide in the form of granules or a powder is used, the powdered particles preferably having a size in the region of 200 ⁇ m.
- the granules of titanium dioxide 1 are held in a basket 2 below a carbon anode 3 located in a crucible 4 having a molten salt 5 therein. These are prevented from sintering together by maintaining particle motion by any appropriate method e.g. in a fluidised bed arrangement.
- Agitation is provided either by mechanical vibration or by the injection of gas underneath the basket. Mechanical vibration can, for example, be provided by ultrasonic transducers mounted on the outside of the crucible or on control rods.
- the key variables to be adjusted are the frequency and amplitude of the vibrations in order to get an average particle contact time which is long enough to get reduction, but short enough to prevent diffusion bonding of the particles into a solid mass. Similar principles would apply to agitation by the injection of gas, except here the flow rate of the gas and size of the gas bubbles would be the variables controlling particle contact time.
- a metal is deposited onto a cathode (based on the electrolytic process previously described) from a second source of the metal at a more positive potential, the resulting metal deposited thereon is dendritic in structure. This is particularly so where the metal is titanium.
- This form of titanium is easy to break up in to a powder as individual particles are connected together only by a small surface area.
- This method can be used to produce titanium powder from titania. In this method, illustrated in Figure 2 , a second cathode 6 is provided which is maintained at a potential that is more negative than the first cathode 7.
- Continuously feeding a fine powder of metal oxide into the electrochemical cell allows for a constant current and a higher reaction rate.
- a carbon electrode is preferred for this method. This method permits the use of cheaper feedstock as a sintering and/or forming stage is no longer needed.
- FIG. 3 shows a conducting crucible 1 which is made the cathode containing a molten salt 2 and inserted therein is an anode 3. Titanium dioxide powder 4 is fed into the crucible where it undergoes reduction and is deposited at the base of the crucible.
- the thick arrow shows the increasing thickness of the reduced feedstock 5.
- the purity of the metal powder may be affected by the starting materials and processing parameters used. For example, it has been found that some variations of the method when used to produce titanium powder result in powder that contains "contaminating impurities" resulting wherefrom, including light metals such as magnesium or calcium, as well as salts such as calcium chloride (the latter being a preferred electrolyte). Such impurities are known to affect the mechanical properties of alloyed metal components, for example, salt inclusions are known to affect the fatigue performance and weldability of titanium alloys.
- a method for purifying metal M 1 particles manufactured by an electrochemical reduction process comprising the steps of:
- the present invention thus provides a method for purifying electrochemically reduced metal particles so as to reduce or remove the aforementioned "contaminating impurities" introduced by the reduction process, so as to enable, for example, direct use of the electrolytically reduced metals in lower temperature powder metallurgy processes.
- the kinds of impurities introduced by such electro-reduction processes are usually more volatile than the metal M 1 and may be conveniently removed by the present process.
- Such impurities may comprise light metals, for example, calcium and magnesium, as well as salts from the electrolyte, such as calcium chloride.
- the impurities should preferably be more volatile than the metal M 1 by at least a factor of ten, or preferably 20, in terms of their respective vapour pressures at the processing temperature.
- the processing temperature and/or heating time should be sufficient to remove substantially all the contaminating impurities, for example, so as to reduce their total level to less than 50 ppm, or less than 10% their initial total concentration.
- the process is conducted so that there is little or no evaporation (for example, less than 5%) of the metal M 1 .
- metal powders produced by electrolytic reduction of oxide or oxides are desirable, and a fully dense spherical particle morphology is preferred, for example in order to impart good flowability.
- the particles may only be partially melted in order to remove said impurities, in most cases the particles need to be fully melted to achieve dense, spherical particles.
- the heat source is arranged such that the metal particles may be allowed to free fall through the heat source.
- Suitable heat sources include but are not strictly limited to a hot plasma torch, a hot gas flame, a tube furnace, an induction coil, electric arcs and lasers.
- the particles may be blown through a plasma torch into the flame and allowed to free fall into a collecting vessel.
- the torch is preferably arranged at a sufficient height above the vessel such that any portion of the particles that is melted by the heat source is substantially solidified before collection. This prevents distortion of the shape of the particles.
- the established method of levitation melting may be used to hold particles of powder in a surrounding heat source for a period sufficient to vaporise the impurities.
- zero gravity processing may be used. The common purpose of these embodiments is to suspend the particles individually in mid-air, out of contact with any surfaces, so as to enable particles to be heated and melted and resolidified individually, without contact with each other, or a container.
- the temperature of the heat source should be at or above the melting point of the metal M 1 .
- the desired point is about 1680°C and for titanium alloys approximately 1500-1800°C.
- an argon or helium arc plasma torch can achieve temperatures sufficient to melt titanium powder particles entrained in the flame.
- the process is conducted in a controlled atmosphere, for example, at low pressure/vacuum and/or in an inert atmosphere.
- the powder particles are kept separate from oxygen or nitrogen while above a temperature of about 500°C. This is achieved in practice either by processing in a vacuum or in an atmosphere of Ar.
- the method is applicable to all metals and alloys provided a temperature sufficient to melt the particles and volatise the contaminants can be achieved.
- the step of removing the impurities may simply involve allowing them to be swept away by the gas flow from the flame of the heat source.
- the step of removing the impurities involves condensing the vaporised impurities on cold collector plates positioned adjacent the hot gas flame and disposing of the condensed impurities. Additionally, if the contaminants re-condense onto the surfaces of the powder particles M 1 , then they can be removed easily with a water or dilute acid wash.
- the inventors have appreciated that by exposing small particles of a metal M 1 to a heat source at around or above the melting point, but below the boiling point of M 1 , and allowing them to fall freely through the heat source, the shape of the particles can be altered to a near spherical shape. Spherical particles provide improved bonding in powder metallurgy processes.
- the temperature of the heat source used in the purification process of the method is substantially equal to or higher than the melting point of M 1 but lower than the boiling point of M 1 .
- Powdered particles purified in accordance with the method of the invention may be used in the formation of alloy metal articles made by various powder metallurgy methods and will provide improved particle bonding and mechanical properties in the alloyed article.
- the invention provides a method for the manufacture of a metal article containing a metal M 1 , by purifying metal M 1 particles as set out in the first aspect of the invention above and performing a powder metallurgy process on the particles to form the article.
- the temperature of the heat source will be substantially equal to or above the melting point of the metal M 1 .
- the electrochemical reduction method may comprise any suitable electro-reduction method for the production of metal particles, and includes the methods described herein or as described in WO 99/64638 .
- the powder metallurgy process used may be any conventional powder metallurgy process including but not limited to powder sintering and/or forging.
- powder sintering and/or forging One example of such a process is hot isostatic pressing.
- Purified powders made according to the first aspect of the invention may be used in various other processes for the manufacture of metal articles where powdered starting materials are desirable.
- M 1 may be construed to mean a single metal or a combination of different metals formed in a single method.
- References to particles may be construed to mean a powder or other finely sized metal samples, for example, granules or pellets, that could be purified by the present method.
- a powder may be construed to comprise small particles up to about 1mm in diameter.
- Figures 1 to 3 show, by way of example, three suitable prior art arrangements for producing metal powders by electrolytic reduction, and are discussed in more detail above.
- FIG 4 shows a preferred arrangement for purifying a powder in which the particles are blown through a plasma torch into a flame and allowed to free fall into a collecting means.
- the reactor 10 comprises a large metal vessel 11, provided with an inert atmosphere 12, which is preferably argon dispensed from jets 9.
- an inert atmosphere 12 which is preferably argon dispensed from jets 9.
- the metal particles (M 1 ) enter the vessel from a supply hopper 14 through the plasma torch 13, which is attached and sealed to the top of the vessel 11 so that it points downwards, and provides sufficient heat to melt and vaporise the metal particles and contaminants, respectively, as they pass through the upper section of the vessel 11.
- the torch 13 is preferably arranged at a sufficient height above the collecting means that any portion of the particles that is melted by the heat source is substantially solidified before collection. This prevents distortion of the shape of the particles.
- the re-solidified powder is collected and sealed into a metal collection hopper 15 via a funnel cyclone collector 16.
- levitation melting is used to hold particles of powder in a surrounding heat source for a period sufficient to vaporise the impurities.
- the apparatus comprises a supply hopper 14 through which metal particles (M 1 ) enter via a valve 24 into a large ceramic tube-like chamber 23.
- the powder is allowed to fall through the ceramic tube under its own weight.
- an external concentric electromagnetic induction coil 22 Around the mid-section of the chamber 23 is an external concentric electromagnetic induction coil 22, which both heats and levitates the metal powder particles such that they spend sufficient time at a suitable temperature for volatile contamination removal and spheroidisation to take place.
- the purified powder then falls to the bottom of the chamber 23, cooling sufficiently to solidify, before exiting via valve 25 and being collected and sealed into a metal canister 15.
- an inert gas flow is introduced counter to the direction of the metal powder flow via inlet 21 and outlet 20, and this both enhances the cooling of the powder particles at the lower end of the tube, and also helps to carry away volatile species.
- An electro-reduction process also known as an electro-deoxidation (EDO) process, is less expensive and easier to perform than conventional metal extraction methods.
- Metal particles produced by an EDO process may advantageously be used directly as feedstocks in manufacturing processes that incorporate the present purification process as an integral stage.
- Such a manufacturing process has, in particular, significant benefits over conventional processes for the production of titanium articles.
- Conventional methods for the manufacture of titanium and titanium alloy stock involve hot working of large titanium alloy ingots. The high temperatures and pressures required for these processes contribute to the high cost of this stock compared to other metal products such as steel and aluminium alloys.
- Titanium is conventionally obtained from its ore by the Kroll route, a complex chlorination and magnesium reduction method.
- the purified metal granules, called sponge are then melted with the alloying additions and cast into large titanium alloy ingots.
- the metal is melted at least twice and sometimes more, in order to ensure chemical homogeneity and freedom from defects.
- the large titanium alloy ingots are then hot forged repeatedly to produce the semi-finished alloy stock shapes, such as bar, plate, sheet and wire, required for the manufacture of articles.
- the present invention aims to provide novel methods for the manufacture of titanium or other metal alloy stock, which are less expensive and easier to perform.
- the above-mentioned manufacturing process incorporating the purification stage may involve:
- pellets should be heated sufficiently to allow them to coalesce to form a sheet when subjected to the pressure of the nip, and may be heated so that they soften, or, at least partly melt, or even fully melt.
- pellet covers particles ranging from powders to granules.
- either or both of the feed rollers are water cooled by passing a coolant through their centres.
- a coolant is water, other suitable fluids will no doubt occur to the skilled addressee.
- the above-mentioned manufacturing process incorporating the purification stage may involve:
- the sheet or cast stock may be allowed to cool or may be actively cooled.
- the alloy pellets may be obtained by an electro-deoxidation process such as that described in WO 99/64638 , or, in the Applicant's co-pending applications GB2359564 or GB2362164 . As is described in the above specifications, electrochemical reduction may be used to provide small pellets of alloy having high purity and good grain structure. Thus, heating and purification involving softening or partially melting the pellets is sufficient to bond the pellets and obtain a mass of alloy having good mechanical properties.
- the step of heating the pellets is preferably carried out by means of an energy beam.
- the energy beam may, optionally, be selected from an electron beam, a laser or a plasma torch.
- the processing temperature and/or heating time should be sufficient to remove substantially all the contaminating impurities, for example, so as to reduce their total level to less than 50 ppm, or less than 10% their initial total concentration.
- the process is conducted so that there is little or no evaporation (for example, less than 5%) of the metal.
- the process is conducted in a controlled atmosphere, for example, at low pressure/vacuum and/or in an inert atmosphere.
- a controlled atmosphere for example, at low pressure/vacuum and/or in an inert atmosphere.
- Ti it is important that the powder particles are kept separate from oxygen or nitrogen while above a temperature of about 500°C. This is achieved in practice either by processing in a vacuum or in an atmosphere of Ar.
- the use of argon or helium arc torches is particularly preferred.
- the rolled or cast stock may be further processed, for example, by one or more additional intermediate steps such as further working or heat treatments of the stock, prior to final cooling.
- Products of the methods are comprised of fully dense metal alloy.
- the homogeneity of the final metal is improved considerably because the pellets are provided via an electrochemical reduction method, as compared to the alternative of using Kroll sponge and powder or particles of the alloy additions.
- the present methods require considerably less cumbersome and costly apparatus compared to conventional methods where the starting materials are introduced to the casting or rolling apparatus fully molten and are particularly suited to the production of small quantities of stock where mechanical properties and metal homogeneity are of importance.
- the present methods are particularly suited to the manufacture of low volume or small size products, which could be prohibitively costly to produce by conventional methods.
- pellets of titanium metal or alloy 31 are delivered through a hopper 32 to a pair of counter-rotating feed rollers 33a, 33b.
- the rollers are cooled by a water-cooling system (not shown).
- An energy beam 34 is arranged to concentrate a beam of energy along a line just above the nip of rollers 33a, 33b and causes at least partial melting of the pellets seated on and between the rollers.
- the rollers 33a, 33b rotate, the at least partially melted pellets are drawn into the nip and are squeezed together to form a solid mass of the titanium or titanium alloy in the form of a sheet 35.
- the hot sheet falls to a conveyor 36 and is carried away for further processing and/or cooling.
- Figure 7 illustrates a similar arrangement for the production of bar stock having a square cross-section.
- a source of pellets 41 is delivered through a hopper 42 to a shallow crucible 47.
- a laser 44 is mounted on a track 48 along which the energy beam sweeps back and forth.
- the energy beam is aimed at the top surface of the crucible 47 and causes at least partial melting of the pellets 41 delivered thereto.
- the metal is drawn through a square shaped die 49 communicating with a lower surface of the crucible 47 and bar stock 45 of the titanium or titanium alloy emerges.
- the bar stock may be cut to length by a cutter (not shown).
- the bar stock is collected by a conveyor system 46 and removed for cooling and/or further processing.
- the feedstock in the form of pellets is stored inside a hopper that is an integral part of a vacuum chamber housing the roller and for example, E-beam (electron-beam) or a laser beam melting assembly.
- E-beam electron-beam
- the vacuum chamber is desirably at a pressure ranging from 1 x 10 -6 to 1 x 10 -5 mBar during the operation.
- the energy beam directed at the pellets heats and at least partially melts the titanium feedstock between the roller gap, which either softens it sufficiently for it to be deformed and consolidated as it passes through the roll gap, or melts it then solidifies it instantaneously on contacting the rollers and also gets deformed into a strip subsequently.
- the temperature of the solid strip coming out of the rollers is in the region of 600°C.
- This method is not specific only to titanium feedstock, it has potential application for direct production of strips of any metallic powder, and especially those that are very sensitive to the absorption of impurities such as oxygen or nitrogen.
- the method of manufacture of strip described above is ideally suited to feed stock of uniformly sized granules of less than about 1 mm dimensions. Larger granules may be optimal for production of thicker sheets by this method.
- Rollers are desirably cooled through the centre.
- the primary requirement is that the chamber housing the rollers should be in a vacuum (or very low pressure environment) to stop the molten titanium from picking up oxygen.
- a water-cooled roller assembly has been developed by the applicants that lets the water flow through the rollers and bearings, while maintaining good vacuum tightness.
- the heating is conducted so as simultaneously to remove all or part of any volatile contamination that may be present in the feed material, for example, EDO granules may contain contaminants such as calcium chloride, calcium oxide or calcium metal.
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Abstract
Description
- This invention relates to a method for the purification of metal particles, for example, metal powders and other finely sized metal samples, and, in particular, to ones that have been produced by the process of electrochemical reduction of metal compounds. The invention is particularly suited to the purification of titanium powder formed from the electrolytic reduction of titanium oxide TiO2.
-
WO 99/64638 -
GB2359564 - Sintered granules or powders of metal oxide can be used as the feedstock for the electrolysis described in the above referenced method, as long as appropriate conditions are present. In one example, powdered titanium dioxide in the form of granules or a powder is used, the powdered particles preferably having a size in the region of 200µm.
- As illustrated in
Figure 1 , the granules oftitanium dioxide 1 are held in abasket 2 below acarbon anode 3 located in acrucible 4 having amolten salt 5 therein. These are prevented from sintering together by maintaining particle motion by any appropriate method e.g. in a fluidised bed arrangement. Agitation is provided either by mechanical vibration or by the injection of gas underneath the basket. Mechanical vibration can, for example, be provided by ultrasonic transducers mounted on the outside of the crucible or on control rods. The key variables to be adjusted are the frequency and amplitude of the vibrations in order to get an average particle contact time which is long enough to get reduction, but short enough to prevent diffusion bonding of the particles into a solid mass. Similar principles would apply to agitation by the injection of gas, except here the flow rate of the gas and size of the gas bubbles would be the variables controlling particle contact time. - If a metal is deposited onto a cathode (based on the electrolytic process previously described) from a second source of the metal at a more positive potential, the resulting metal deposited thereon is dendritic in structure. This is particularly so where the metal is titanium. This form of titanium is easy to break up in to a powder as individual particles are connected together only by a small surface area. This method can be used to produce titanium powder from titania. In this method, illustrated in
Figure 2 , a second cathode 6 is provided which is maintained at a potential that is more negative than the first cathode 7. When the deposition of titanium on the first cathode has progressed sufficiently, the second electrode is switched on, leading to the dissolution of titanium from the first cathode anddeposition 8 onto the second cathode 6 in dendritic form. The other reference numerals represent the same items as inFigure 1 . - Continuously feeding a fine powder of metal oxide into the electrochemical cell allows for a constant current and a higher reaction rate. A carbon electrode is preferred for this method. This method permits the use of cheaper feedstock as a sintering and/or forming stage is no longer needed.
- This method is shown in
Figure 3 which shows a conductingcrucible 1 which is made the cathode containing amolten salt 2 and inserted therein is ananode 3.Titanium dioxide powder 4 is fed into the crucible where it undergoes reduction and is deposited at the base of the crucible. The thick arrow shows the increasing thickness of the reducedfeedstock 5. - In electro-reduction methods such as those exemplified above, the purity of the metal powder may be affected by the starting materials and processing parameters used. For example, it has been found that some variations of the method when used to produce titanium powder result in powder that contains "contaminating impurities" resulting wherefrom, including light metals such as magnesium or calcium, as well as salts such as calcium chloride (the latter being a preferred electrolyte). Such impurities are known to affect the mechanical properties of alloyed metal components, for example, salt inclusions are known to affect the fatigue performance and weldability of titanium alloys.
- A consequence of the presence of those contaminating impurities in electrolytically reduced metal powders is that they are unsuitable for use in lower temperature powder metallurgy processes such as sintering or forging which are performed at temperatures below the alloy melting temperature.
- Conventional methods for removing contaminants from metals are described in published patent application
EP 0047665 and patent numberUS 4,727,928 . InEP 0047665 , a charge comprising metal sponge and a sponge-forming reaction product is heated in a retort means to a temperature sufficient to cause evaporation of the reaction products from the metal sponge. The reaction products are then conducted to a condenser means where they are condensed. InUS 4,727,928 , tantalum or niobium containing volatile impurities, such as sodiothermic tantalum powder or scrap tantalum from capacitor (condenser) anodes, is converted into crude cast metal by plasma melting. The crude cast metal is then submitted to electron beam melting to produce refined cast metal. - The invention provides a method as defined in the appended independent claims, to which reference should now be made. Preferred or advantageous features of the invention are set out in dependent claims.
- In accordance with a first aspect of the present invention there is provided a method for purifying metal M1 particles manufactured by an electrochemical reduction process, the method comprising the steps of:
- introducing the metal M1 particles into a heat source, such that the particles are out of contact with any surfaces, at a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present;
- removing the vaporised impurities from the vicinity of the particles;
- and cooling the purified metal M1 particles for collection in solid form.
- The present invention thus provides a method for purifying electrochemically reduced metal particles so as to reduce or remove the aforementioned "contaminating impurities" introduced by the reduction process, so as to enable, for example, direct use of the electrolytically reduced metals in lower temperature powder metallurgy processes.
- It has been found that the kinds of impurities introduced by such electro-reduction processes are usually more volatile than the metal M1 and may be conveniently removed by the present process. Such impurities may comprise light metals, for example, calcium and magnesium, as well as salts from the electrolyte, such as calcium chloride. For effective removal of impurities without significant loss of metal M1, the impurities should preferably be more volatile than the metal M1 by at least a factor of ten, or preferably 20, in terms of their respective vapour pressures at the processing temperature. Preferably, the processing temperature and/or heating time should be sufficient to remove substantially all the contaminating impurities, for example, so as to reduce their total level to less than 50 ppm, or less than 10% their initial total concentration. Preferably the process is conducted so that there is little or no evaporation (for example, less than 5%) of the metal M1.
- Another feature of metal powders produced by electrolytic reduction of oxide or oxides is that the powder particles tend to be irregular in shape, contain internal cavities and have a rough outer surface. For certain powder metallurgy processes these features are undesirable, and a fully dense spherical particle morphology is preferred, for example in order to impart good flowability. Hence, although the particles may only be partially melted in order to remove said impurities, in most cases the particles need to be fully melted to achieve dense, spherical particles.
- Desirably, the heat source is arranged such that the metal particles may be allowed to free fall through the heat source. Suitable heat sources include but are not strictly limited to a hot plasma torch, a hot gas flame, a tube furnace, an induction coil, electric arcs and lasers.
- In one embodiment of the invention, the particles may be blown through a plasma torch into the flame and allowed to free fall into a collecting vessel. The torch is preferably arranged at a sufficient height above the vessel such that any portion of the particles that is melted by the heat source is substantially solidified before collection. This prevents distortion of the shape of the particles.
- In another embodiment the established method of levitation melting may be used to hold particles of powder in a surrounding heat source for a period sufficient to vaporise the impurities. In a further embodiment, zero gravity processing may be used. The common purpose of these embodiments is to suspend the particles individually in mid-air, out of contact with any surfaces, so as to enable particles to be heated and melted and resolidified individually, without contact with each other, or a container.
- The temperature of the heat source should be at or above the melting point of the metal M1. For titanium the desired point is about 1680°C and for titanium alloys approximately 1500-1800°C. It is known that an argon or helium arc plasma torch can achieve temperatures sufficient to melt titanium powder particles entrained in the flame. Ideally, the process is conducted in a controlled atmosphere, for example, at low pressure/vacuum and/or in an inert atmosphere. In the case of Ti it is important that the powder particles are kept separate from oxygen or nitrogen while above a temperature of about 500°C. This is achieved in practice either by processing in a vacuum or in an atmosphere of Ar.
- The method is applicable to all metals and alloys provided a temperature sufficient to melt the particles and volatise the contaminants can be achieved.
- The step of removing the impurities may simply involve allowing them to be swept away by the gas flow from the flame of the heat source. Preferably, the step of removing the impurities involves condensing the vaporised impurities on cold collector plates positioned adjacent the hot gas flame and disposing of the condensed impurities. Additionally, if the contaminants re-condense onto the surfaces of the powder particles M1, then they can be removed easily with a water or dilute acid wash.
- Aside from improving the purity of the metal powder, the inventors have appreciated that by exposing small particles of a metal M1 to a heat source at around or above the melting point, but below the boiling point of M1, and allowing them to fall freely through the heat source, the shape of the particles can be altered to a near spherical shape. Spherical particles provide improved bonding in powder metallurgy processes. Thus it is preferred that the temperature of the heat source used in the purification process of the method is substantially equal to or higher than the melting point of M1 but lower than the boiling point of M1.
- Powdered particles purified in accordance with the method of the invention may be used in the formation of alloy metal articles made by various powder metallurgy methods and will provide improved particle bonding and mechanical properties in the alloyed article.
- In another aspect, the invention provides a method for the manufacture of a metal article containing a metal M1, by purifying metal M1 particles as set out in the first aspect of the invention above and performing a powder metallurgy process on the particles to form the article.
- This method may advantageously comprise the steps of:
- electrochemically reducing a source of a compound of the general formula M1X to remove substantially all of element X and provide powder particles consisting substantially of metal M1;
- introducing the metal powder M1 into a heat source at a temperature substantially equal to or higher than melting point of M1 for a period of time sufficient to cause vaporisation of a significant proportion of the one or more impurities;
- removing the vaporised impurities;
- cooling the purified metal M1 powder; and
- mixing the purified M1 powder with powder of other alloy components and,
- performing a powder metallurgy process on the mixture to form an alloyed article.
- Preferably, the temperature of the heat source will be substantially equal to or above the melting point of the metal M1.
- The electrochemical reduction method may comprise any suitable electro-reduction method for the production of metal particles, and includes the methods described herein or as described in
WO 99/64638 - The powder metallurgy process used may be any conventional powder metallurgy process including but not limited to powder sintering and/or forging. One example of such a process is hot isostatic pressing.
- Purified powders made according to the first aspect of the invention may be used in various other processes for the manufacture of metal articles where powdered starting materials are desirable.
- For the purposes of this specification M1 may be construed to mean a single metal or a combination of different metals formed in a single method. References to particles may be construed to mean a powder or other finely sized metal samples, for example, granules or pellets, that could be purified by the present method. A powder may be construed to comprise small particles up to about 1mm in diameter.
- Examples employing the present invention will now be described in more detail, by way of example only, with reference to the accompanying drawings of which:
-
Figure 1 shows a prior art electrolytic cell in which the metal oxide to be reduced is in the form of granules; -
Figure 2 shows a prior art electrolytic cell in which an additional cathode is provided in order to refine the metal to a dendritic form; -
Figure 3 shows a prior art electrolytic cell employing a continuous powder feed; -
Figure 4 shows a preferred purification apparatus according to the present invention; -
Figure 5 shows an alternative purification apparatus according to the present invention; -
Figure 6 shows a schematic illustration of an apparatus for the production of titanium metal or alloy sheet; and, -
Figure 7 shows a schematic illustration of an apparatus for the production of titanium metal or alloy bar stock. -
Figures 1 to 3 show, by way of example, three suitable prior art arrangements for producing metal powders by electrolytic reduction, and are discussed in more detail above. -
Figure 4 shows a preferred arrangement for purifying a powder in which the particles are blown through a plasma torch into a flame and allowed to free fall into a collecting means. Thereactor 10 comprises alarge metal vessel 11, provided with aninert atmosphere 12, which is preferably argon dispensed from jets 9. For titanium, the process should be entirely contained in a metal vessel in an inert gas atmosphere. The metal particles (M1) enter the vessel from asupply hopper 14 through theplasma torch 13, which is attached and sealed to the top of thevessel 11 so that it points downwards, and provides sufficient heat to melt and vaporise the metal particles and contaminants, respectively, as they pass through the upper section of thevessel 11. Thetorch 13 is preferably arranged at a sufficient height above the collecting means that any portion of the particles that is melted by the heat source is substantially solidified before collection. This prevents distortion of the shape of the particles. The re-solidified powder is collected and sealed into ametal collection hopper 15 via afunnel cyclone collector 16. - In the alternative embodiment shown in
Figure 5 , levitation melting is used to hold particles of powder in a surrounding heat source for a period sufficient to vaporise the impurities. The apparatus comprises asupply hopper 14 through which metal particles (M1) enter via a valve 24 into a large ceramic tube-like chamber 23. The powder is allowed to fall through the ceramic tube under its own weight. Around the mid-section of thechamber 23 is an external concentricelectromagnetic induction coil 22, which both heats and levitates the metal powder particles such that they spend sufficient time at a suitable temperature for volatile contamination removal and spheroidisation to take place. The purified powder then falls to the bottom of thechamber 23, cooling sufficiently to solidify, before exiting via valve 25 and being collected and sealed into ametal canister 15. In a further refinement, an inert gas flow is introduced counter to the direction of the metal powder flow viainlet 21 andoutlet 20, and this both enhances the cooling of the powder particles at the lower end of the tube, and also helps to carry away volatile species. - An electro-reduction process, also known as an electro-deoxidation (EDO) process, is less expensive and easier to perform than conventional metal extraction methods. Metal particles produced by an EDO process may advantageously be used directly as feedstocks in manufacturing processes that incorporate the present purification process as an integral stage.
- An embodiment of the present invention provides a method for the manufacture of a metal alloy article of uniform cross section comprising the steps of:
- introducing a continuous source of metal alloy M1 pellets, manufactured by an electrochemical reduction process, to a processing means;
- heating the pellets as they approach the processing means, by free-fall through a heat source, to a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present;
- removing the vaporised impurities from the vicinity of the pellets;
- drawing the metal through the processing means so as to coalesce the pellets to form the desired article; and,
- cooling the cast stock.
- Such a manufacturing process has, in particular, significant benefits over conventional processes for the production of titanium articles. Conventional methods for the manufacture of titanium and titanium alloy stock involve hot working of large titanium alloy ingots. The high temperatures and pressures required for these processes contribute to the high cost of this stock compared to other metal products such as steel and aluminium alloys. Titanium is conventionally obtained from its ore by the Kroll route, a complex chlorination and magnesium reduction method. The purified metal granules, called sponge, are then melted with the alloying additions and cast into large titanium alloy ingots. The metal is melted at least twice and sometimes more, in order to ensure chemical homogeneity and freedom from defects. The large titanium alloy ingots are then hot forged repeatedly to produce the semi-finished alloy stock shapes, such as bar, plate, sheet and wire, required for the manufacture of articles.
- The present invention aims to provide novel methods for the manufacture of titanium or other metal alloy stock, which are less expensive and easier to perform.
- For sheet production, the above-mentioned manufacturing process incorporating the purification stage may involve:
- introducing the continuous source of pellets of the metal alloy to a pair of cooled feed rollers;
- heating and simultaneously purifying the pellets in the above described manner as they approach the nip of the pair of feed rollers;
- drawing the metal through the nip of the rollers to form a sheet of metal alloy; and,
- cooling the sheet.
- The pellets should be heated sufficiently to allow them to coalesce to form a sheet when subjected to the pressure of the nip, and may be heated so that they soften, or, at least partly melt, or even fully melt. The term "pellet" covers particles ranging from powders to granules.
- Preferably either or both of the feed rollers are water cooled by passing a coolant through their centres. One suitable coolant is water, other suitable fluids will no doubt occur to the skilled addressee.
- Alternatively, for stock production, the above-mentioned manufacturing process incorporating the purification stage may involve:
- introducing the continuous source of pellets of the metal alloy to a shaped crucible;
- heating and simultaneously purifying the pellets in the above described manner as they approach the exposed surface of the crucible;
- drawing the at least partially molten metal from an opposing surface of the crucible through a die, the die having a cross section of near net shape and dimensions to the desired net shape and dimensions of the required stock; and
- cooling the cast stock.
- The sheet or cast stock may be allowed to cool or may be actively cooled.
- The alloy pellets may be obtained by an electro-deoxidation process such as that described in
WO 99/64638 GB2359564 GB2362164 - The step of heating the pellets is preferably carried out by means of an energy beam. The energy beam may, optionally, be selected from an electron beam, a laser or a plasma torch.
- Preferably, the processing temperature and/or heating time should be sufficient to remove substantially all the contaminating impurities, for example, so as to reduce their total level to less than 50 ppm, or less than 10% their initial total concentration. Preferably the process is conducted so that there is little or no evaporation (for example, less than 5%) of the metal. Ideally, the process is conducted in a controlled atmosphere, for example, at low pressure/vacuum and/or in an inert atmosphere. In the case of Ti it is important that the powder particles are kept separate from oxygen or nitrogen while above a temperature of about 500°C. This is achieved in practice either by processing in a vacuum or in an atmosphere of Ar. The use of argon or helium arc torches is particularly preferred.
- In either method, the rolled or cast stock may be further processed, for example, by one or more additional intermediate steps such as further working or heat treatments of the stock, prior to final cooling. Products of the methods are comprised of fully dense metal alloy. The homogeneity of the final metal is improved considerably because the pellets are provided via an electrochemical reduction method, as compared to the alternative of using Kroll sponge and powder or particles of the alloy additions. The present methods require considerably less cumbersome and costly apparatus compared to conventional methods where the starting materials are introduced to the casting or rolling apparatus fully molten and are particularly suited to the production of small quantities of stock where mechanical properties and metal homogeneity are of importance.
- The present methods are particularly suited to the manufacture of low volume or small size products, which could be prohibitively costly to produce by conventional methods.
- Two embodiments illustrating the roller and crucible based processes will now be further described with reference to
Figures 6 and7 . - As can be seen from
Figure 6 , pellets of titanium metal oralloy 31 are delivered through ahopper 32 to a pair ofcounter-rotating feed rollers energy beam 34 is arranged to concentrate a beam of energy along a line just above the nip ofrollers rollers sheet 35. The hot sheet falls to aconveyor 36 and is carried away for further processing and/or cooling. -
Figure 7 illustrates a similar arrangement for the production of bar stock having a square cross-section. A source ofpellets 41 is delivered through ahopper 42 to ashallow crucible 47. Alaser 44 is mounted on atrack 48 along which the energy beam sweeps back and forth. The energy beam is aimed at the top surface of thecrucible 47 and causes at least partial melting of thepellets 41 delivered thereto. The metal is drawn through a square shaped die 49 communicating with a lower surface of thecrucible 47 andbar stock 45 of the titanium or titanium alloy emerges. The bar stock may be cut to length by a cutter (not shown). The bar stock is collected by aconveyor system 46 and removed for cooling and/or further processing. - The parameters for a method carried using either of the described apparatus are more generally described below.
- The feedstock in the form of pellets (including powder or granules) is stored inside a hopper that is an integral part of a vacuum chamber housing the roller and for example, E-beam (electron-beam) or a laser beam melting assembly. During operation the feedstock is poured over the rollers at a controlled rate using a regulator valve attached to the feeder. The vacuum chamber is desirably at a pressure ranging from 1 x 10-6 to 1 x 10-5 mBar during the operation.
- The energy beam directed at the pellets heats and at least partially melts the titanium feedstock between the roller gap, which either softens it sufficiently for it to be deformed and consolidated as it passes through the roll gap, or melts it then solidifies it instantaneously on contacting the rollers and also gets deformed into a strip subsequently. The temperature of the solid strip coming out of the rollers is in the region of 600°C. Several titanium strips of dimensions in the range 300-900 mm (length) x 60-100 mm (width) x 3.0 mm (thickness) have been produced using this method.
- This method is not specific only to titanium feedstock, it has potential application for direct production of strips of any metallic powder, and especially those that are very sensitive to the absorption of impurities such as oxygen or nitrogen.
- The method of manufacture of strip described above is ideally suited to feed stock of uniformly sized granules of less than about 1 mm dimensions. Larger granules may be optimal for production of thicker sheets by this method.
- Rollers are desirably cooled through the centre. The primary requirement is that the chamber housing the rollers should be in a vacuum (or very low pressure environment) to stop the molten titanium from picking up oxygen. A water-cooled roller assembly has been developed by the applicants that lets the water flow through the rollers and bearings, while maintaining good vacuum tightness.
- For both variants of the invention described here for the production of metal alloy sheet and the production of shaped bar stock by energy beam heating of pellets or granular feed, the heating is conducted so as simultaneously to remove all or part of any volatile contamination that may be present in the feed material, for example, EDO granules may contain contaminants such as calcium chloride, calcium oxide or calcium metal.
Claims (26)
- A method for purifying metal M1 particles manufactured by an electrochemical reduction process, the method comprising the steps of:introducing the metal M1 particles into a heat source, such that the particles are out of contact with any surfaces, at a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present;removing the vaporised impurities from the vicinity of the particles;and cooling the purified metal M1 particles for collection in solid form.
- A method for the manufacture of a metal alloy article containing a metal M1, by purifying the metal M1 particles using the method of Claim 1, and
performing a powder metallurgy process on the particles to form the article. - A method according to Claim 2 wherein the article is a metal alloy article, and in which the purified M1 particles are mixed with particles of other alloy components and the powder metallurgy process is performed on the mixture to form the alloyed article.
- A method as claimed in Claim 1, 2 or 3 wherein the particles are in the form of a powder.
- A method according to Claim 4 wherein the powder comprises particles up to about 1 mm in diameter.
- A method according to Claim 1, 2 or 3 wherein the particles are in the form of finely-sized metal samplers, granules or pellets.
- A method according to any preceding claim wherein when the particles are out of contact with any surfaces, they are suspended in mid-air and/or permitted to free fall past or within the heat source.
- A method according to any of Claims 1 to 6 wherein when the particles are out of contact with any surfaces they are entrained in a flame or blown through a plasma torch or are within an induction coil.
- A method according to any preceding claim wherein the particles are heated, melted and substantially resolidified out of contact with any surfaces.
- A method as claimed in any preceding claim wherein the free fall distance from the heat source is sufficiently long to allow any M1 melted by the heat source to re-solidify before collection.
- A method as claimed in any preceding claim wherein the heat source is selected from any one of a plasma torch, a laser, an electric arc, an induction coil or a tube furnace.
- A method as claimed in any preceding claim, wherein the method is conducted in a controlled atmosphere.
- A method as claimed in any preceding claim conducted in apparatus comprising a heat source, collection means for collecting the purified particles, and separate collection means for collecting the impurities.
- A method as claimed in any preceding claim wherein the heat source is a plasma torch and the step of removing the vaporised impurities involves allowing the impurities to be swept away by the hot gas flow from the torch.
- A method as claimed in any preceding claim wherein the temperature of the heat source is around or above the melting point, but below the boiling point of M1.
- A method according to any preceding claim wherein the metal M1 particles for purification are manufactured by an electrochemical reduction process.
- A method as claimed in any preceding claim wherein M1 comprises titanium.
- A method as claimed in any preceding claim wherein the impurities comprise one or more of magnesium, calcium and calcium chloride.
- A method for the manufacture of a metal alloy article of uniform cross-section comprising the steps of:introducing a continuous source of metal alloy M1 pellets, containing contaminating impurities that are more volatile than M1, to a processing means;heating the pellets as they approach the processing means, by free-fall through a heat source, to a temperature substantially equal to or higher than the melting point of M1 so as to cause vaporisation of some or substantially all of the contaminating impurities present;removing the vaporised impurities from the vicinity of the pellets;drawing the metal through the processing means so as to coalesce the pellets to form the desired article; andcooling the cast stock.
- A method as claimed in Claim 19 for the manufacture of a metal alloy sheet comprising the steps of:introducing the continuous source of pellets to a pair of cooled feed rollers;heating the pellets as specified in Claim 19 as they approach the nip of the pair of feed rollers;drawing the metal through the nip of the rollers to form a sheet of metal alloy; and,cooling the sheet.
- A method as claimed in Claim 19 for the manufacture of a uniform cross-section metal alloy stock, comprising the steps of:introducing the continuous source of pellets of the metal alloy to a shaped crucible;heating the pellets as specified in Claim 19 as they approach the exposed surfaces of the crucible;drawing the at least partially molten metal from an opposing surface of the crucible through a die, the die having a cross-section of near net shape and dimensions to the desired net shape and dimensions of the required stock; and,cooling the cast stock.
- A method as claimed in any of Claims 19 to 21, wherein the step of heating the pellets is carried out by means of an energy beam selected from an electron beam, a laser or a plasma torch.
- A method as claimed in any of Claims 19 to 22, wherein the alloy substantially comprises titanium.
- A method for fabricating purified metal particles comprising spherical particles with a reduced concentration of the volatile impurities using a method as defined in any of Claims 1 to 18.
- A method according to Claim 24, wherein the concentration of the volatile impurities is less than 50ppm.
- A method according to Claim 24 or 25, wherein the concentration of the volatile impurities is less than 10% of their concentration before purification.
Applications Claiming Priority (7)
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GB0222219 | 2002-09-25 | ||
GB0222219A GB0222219D0 (en) | 2002-09-25 | 2002-09-25 | Purification process |
GB0222348 | 2002-09-26 | ||
GB0222358A GB2393451A (en) | 2002-09-26 | 2002-09-26 | A Method of Manufacture of Metal Alloy Sheet |
GB0222358 | 2002-09-26 | ||
GB0222348A GB2393450A (en) | 2002-09-26 | 2002-09-26 | Method of Manufacture of Metal Alloy Stock |
PCT/GB2003/004093 WO2004029332A2 (en) | 2002-09-25 | 2003-09-24 | Purification of electrochemically deoxidised refractory metal particles by heat processing |
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EP1543172B1 true EP1543172B1 (en) | 2009-12-16 |
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Families Citing this family (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1689519B1 (en) * | 2003-08-28 | 2012-06-20 | Tekna Plasma Systems Inc. | Process for the synthesis, separation and purification of powder materials |
EP1671711A1 (en) * | 2003-10-09 | 2006-06-21 | Ebara Corporation | Method of purifying matter contaminated by heavy metal and apparatus therefor |
AU2015259108B2 (en) | 2014-05-13 | 2018-03-01 | University Of Utah Research Foundation | Production of substantially spherical metal powers |
AU2015358534A1 (en) | 2014-12-02 | 2017-07-20 | University Of Utah Research Foundation | Molten salt de-oxygenation of metal powders |
WO2017069341A1 (en) * | 2015-10-22 | 2017-04-27 | (주)포스코 | Raw material charging device, cooling roller, and method for preventing generation of stuck ores |
CA3009630C (en) | 2015-12-16 | 2023-08-01 | Amastan Technologies Llc | Spheroidal dehydrogenated metals and metal alloy particles |
US11077497B2 (en) | 2017-06-07 | 2021-08-03 | Global Titanium Inc. | Deoxidation of metal powders |
CN114007782A (en) | 2019-04-30 | 2022-02-01 | 6K有限公司 | Mechanically alloyed powder feedstock |
US11611130B2 (en) | 2019-04-30 | 2023-03-21 | 6K Inc. | Lithium lanthanum zirconium oxide (LLZO) powder |
CN114641462A (en) | 2019-11-18 | 2022-06-17 | 6K有限公司 | Unique raw material for spherical powder and manufacturing method |
US11590568B2 (en) | 2019-12-19 | 2023-02-28 | 6K Inc. | Process for producing spheroidized powder from feedstock materials |
US11181325B2 (en) * | 2019-12-23 | 2021-11-23 | Valgroup S.A. | System for the production of molten salt used as a heat transfer medium for a pyrolysis system |
CA3180426A1 (en) | 2020-06-25 | 2021-12-30 | Richard K. Holman | Microcomposite alloy structure |
CN116547068A (en) | 2020-09-24 | 2023-08-04 | 6K有限公司 | System, apparatus and method for starting plasma |
JP2023548325A (en) | 2020-10-30 | 2023-11-16 | シックスケー インコーポレイテッド | System and method for the synthesis of spheroidized metal powders |
US20240157442A1 (en) * | 2021-03-10 | 2024-05-16 | The Regents Of The University Of California | Gas-phase production of aligned metal nanoparticles using external magnetic fields |
US20220324022A1 (en) * | 2021-03-31 | 2022-10-13 | 6K Inc. | Microwave plasma processing of spheroidized copper or other metallic powders |
CN113999981A (en) * | 2021-11-02 | 2022-02-01 | 广东先导微电子科技有限公司 | Impurity removal method for high-purity metal through vacuum sublimation |
CN115846649A (en) * | 2022-12-20 | 2023-03-28 | 江苏宇钛新材料有限公司 | Preparation method of low-melting-point spherical metal powder |
Family Cites Families (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2943032A (en) * | 1951-06-23 | 1960-06-28 | Nat Res Corp | Electrolytic production of titanium |
US2876094A (en) * | 1956-02-17 | 1959-03-03 | Du Pont | Production of refractory metals |
US3343944A (en) * | 1963-09-06 | 1967-09-26 | Pechiney Prod Chimiques Sa | Electrolytic beryllium granules and method for manufacturing same |
FR1445684A (en) * | 1965-06-03 | 1966-07-15 | Commissariat Energie Atomique | Device for continuous casting of refractory materials |
US3690635A (en) * | 1969-05-16 | 1972-09-12 | Air Reduction | Condensate collection means |
US4114251A (en) * | 1975-09-22 | 1978-09-19 | Allegheny Ludlum Industries, Inc. | Process for producing elongated metal articles |
EP0047665A1 (en) * | 1980-09-08 | 1982-03-17 | Westinghouse Electric Corporation | Improvements in or relating to metal distillation |
US4390368A (en) * | 1981-04-01 | 1983-06-28 | Gte Products Corporation | Flame spray powder |
AT380491B (en) * | 1984-02-03 | 1986-05-26 | Kos Bernd | METHOD AND DEVICE FOR THE PREPARATION OF CHIPS FROM THE MACHINING OF TITANIUM WORKPIECES |
US4602947A (en) * | 1984-11-01 | 1986-07-29 | Alti Corporation | Process for producing titanium metal and titanium metal alloys |
US4612179A (en) * | 1985-03-13 | 1986-09-16 | Sri International | Process for purification of solid silicon |
LU86090A1 (en) * | 1985-09-23 | 1987-04-02 | Metallurgie Hoboken | PROCESS FOR PREPARING AFFINANT TANTALUM OR NIOBIUM |
JPS63183145A (en) * | 1987-01-22 | 1988-07-28 | Sumitomo Electric Ind Ltd | High hardness titanium-aluminum-vanadium alloy and its production |
US5336378A (en) * | 1989-02-15 | 1994-08-09 | Japan Energy Corporation | Method and apparatus for producing a high-purity titanium |
EP0476651B1 (en) * | 1990-09-20 | 1996-03-20 | Fujitsu Limited | Josephson device having an overlayer structure with improved thermal stability |
US5147451A (en) * | 1991-05-14 | 1992-09-15 | Teledyne Industries, Inc. | Method for refining reactive and refractory metals |
US6024847A (en) * | 1997-04-30 | 2000-02-15 | The Alta Group, Inc. | Apparatus for producing titanium crystal and titanium |
US6309595B1 (en) * | 1997-04-30 | 2001-10-30 | The Altalgroup, Inc | Titanium crystal and titanium |
GB9812169D0 (en) * | 1998-06-05 | 1998-08-05 | Univ Cambridge Tech | Purification method |
JP2001020065A (en) * | 1999-07-07 | 2001-01-23 | Hitachi Metals Ltd | Target for sputtering, its production and high melting point metal powder material |
JP3053183B1 (en) * | 1999-08-27 | 2000-06-19 | 科学技術振興事業団 | Floating melting using pseudo-microgravity field by magnetic force |
GB2359564B (en) * | 2000-02-22 | 2004-09-29 | Secr Defence | Improvements in the electrolytic reduction of metal oxides |
-
2003
- 2003-09-24 AU AU2003271852A patent/AU2003271852B2/en not_active Ceased
- 2003-09-24 AT AT03753690T patent/ATE452214T1/en active
- 2003-09-24 WO PCT/GB2003/004093 patent/WO2004029332A2/en not_active Application Discontinuation
- 2003-09-24 DE DE60330577T patent/DE60330577D1/en not_active Expired - Lifetime
- 2003-09-24 EP EP03753690A patent/EP1543172B1/en not_active Expired - Lifetime
- 2003-09-24 US US10/529,234 patent/US20060130610A1/en not_active Abandoned
-
2012
- 2012-05-22 US US13/477,368 patent/US20120230860A1/en not_active Abandoned
Also Published As
Publication number | Publication date |
---|---|
US20060130610A1 (en) | 2006-06-22 |
ATE452214T1 (en) | 2010-01-15 |
WO2004029332A3 (en) | 2004-10-21 |
US20120230860A1 (en) | 2012-09-13 |
WO2004029332A2 (en) | 2004-04-08 |
EP1543172A2 (en) | 2005-06-22 |
AU2003271852A1 (en) | 2004-04-19 |
AU2003271852B2 (en) | 2010-03-11 |
DE60330577D1 (en) | 2010-01-28 |
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