Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C14/00—Alloys based on titanium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/105—Sintering only by using electric current other than for infrared radiant energy, laser radiation or plasma ; by ultrasonic bonding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/12—Both compacting and sintering
  • B22F3/14—Both compacting and sintering simultaneously
  • B22F3/15—Hot isostatic pressing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/047—Making non-ferrous alloys by powder metallurgy comprising intermetallic compounds
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/10—Alloys containing non-metals
  • C22C1/1084—Alloys containing non-metals by mechanical alloying (blending, milling)
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
  • C22F1/18—High-melting or refractory metals or alloys based thereon
  • C22F1/183—High-melting or refractory metals or alloys based thereon of titanium or alloys based thereon
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
  • B22F2009/041—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by mechanical alloying, e.g. blending, milling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F9/00—Making metallic powder or suspensions thereof
  • B22F9/02—Making metallic powder or suspensions thereof using physical processes
  • B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
  • B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy

Definitions

• the invention relates to a method for producing a high temperature resistant target alloy, in particular a TiAl alloy. Furthermore, the invention relates to a corresponding apparatus for carrying out the method, the corresponding alloy and the use of the apparatus for producing the high temperature resistant target alloy.
• turbomachinery For the operation of turbomachinery special materials for certain components are required due to the conditions of use of the components used in some high temperatures, aggressive environments and high forces acting, which are optimally adapted both by their chemical composition and by their microstructure to the intended use.
• Alloys based on intermetallic titanium aluminide compounds are used in the construction of turbomachinery, such as stationary gas turbines or aircraft engines, for example as a material for rotor blades, since they have the mechanical properties required for the application and additionally have a low specific weight. so that the use of such alloys can increase the efficiency of stationary gas turbines and aircraft engines. Accordingly, there are already a variety of TiAl alloys and methods for producing corresponding components thereof.
• Components made of TiAl alloys can be produced similarly to comparable components from other high-temperature alloys, for example based on Ni, Fe or Co, both by melt metallurgy and powder metallurgy.
• the manufacturing steps additionally or alternatively to the individual steps of the fusion metallurgical production include the use of Powder materials, for example, to produce by alloying a desired composition of the material.
• Powder materials for example, to produce by alloying a desired composition of the material.
• An example of the production of an article of a Ti-Al alloy using powder materials is shown in FIG US 5,424,027 described.
• the powder can be made from a molten bath that is atomized with helium or argon at a very high cooling rate of up to 20,000 K / s.
• the result is a material with a microstructure, which should have a homogeneous and uniform microstructure.
• different particle sizes arise, which have to be separated by fractionation (for example by sieving), so that only the powder containing powder particles with a certain minimum and a certain maximum diameter may be used for the production of a component.
• the powder must be subjected to a multi-stage heat treatment, so that its microstructure is optimized accordingly. These include solution annealing, high temperature annealing, and an aging anneal. For temperatures of over 1000 ° C for several hours are necessary. During these heat treatments, it must be ensured that no oxygen can reach the powder to be heated.
• the alloy used to make the component is provided in the form of a melt and is poured off in a mold.
• the cast material must usually be subjected to suitable forming and / or heat treatments to destroy the cast structure and to set a desired microstructure of the material.
• the corresponding component can then be brought into the desired shape by suitable post-processing, for example by machining, mechanical or electrochemical machining.
• Segregation problems and coarse oxide particle inclusions occur in high alloy TiAl, Fe and Mo alloys in melt metallurgical processes. Segregations include segregation processes in a melt. As a result, within a mixed crystal, the concentration of certain elements at one point increases and the concentration of these elements at another point decreases. This reduces the creep strength of the alloy at high temperatures.
• the object of the present invention is to provide a method and a corresponding device for producing a high-temperature alloy, which on the one hand improves the creep properties and the high-temperature strength of the high-temperature alloy and significantly reduces or prevents contamination of the high-temperature alloy by undesired elements.
• the components of the attritor (4) include, in particular, an attritor container (1), a plurality of grinding balls (3) and / or the agitator (5) with a plurality of grinding arms.
• an attritor container (1) By stirring the grinding balls (3) in the Attritor actually (1) are thrown around and meet the inner walls of the Attritor discloseders (6). Parts of the powder are then located between the surface of the grinding ball (3) and the inner wall of the Attritor (6). Components of the surface or the inner wall (6) can thereby solve and get into the atomic lattice structure of the base material.
• the alloy components would then be reinforced and uncontrolled form metal oxides.
• the rotation takes place at a speed of 30 U / min to 300 U / min for a period of 1 h to 10 h.
• the duration and speed depend on the size of the attritor container (1), the amount of powder (2) in the attritor container, the initial size of the powder particles before mechanical alloying and the desired final size of the powder particles (2) after mechanical alloying ,
• the final size is smaller than the initial size (here in the sense of diameter), because the particles are getting smaller and smaller over time as a result of rubbing against the balls (3) and at the other attritor components.
• the powder (2) is heat treated in such a way, in particular by laser or electron beam melting and / or hot isostatic pressing that fine oxides, in particular a size of 1 to 500 nm, are eliminated and / or the residual oxygen From the crystal grid of the powder is gegettert.
• atomic metals are preferably introduced as alloying constituents in the crystal lattice by the mechanical work.
• the metals include the transition metals and the lanthanides (rare earth metals). These atomic metals have a high oxidizing ability, so that at a sufficient excitation energy, these atomic metals bind to the residual oxygen in the crystal and thus form corresponding metal oxides.
• the ductility, the high temperature strength and the creep resistance of the target alloy increase significantly.
• the goal in forming the metal oxide particles is to keep these particles small in diameter and to distribute them evenly in the material matrix so as to obtain a fine distribution of the metal oxides. This allows the oxide particles to be used in a targeted manner as ODS reinforcing elements (ODS - oxide particle strengthening).
• the hot-isostatic pressing takes place in a temperature range of 1000 ° to 1500 ° for a period of 1h to 10 h at a pressure of 10 MPa to 500 MPa.
• the duration, the temperature and the pressure depend on the desired degree of fine distribution and the desired diameter of the metal oxides.
• the powder of the base material (2) powder grains with a diameter of less than or equal to 500 .mu.m.
• the diameter of the powder grains is greater than or equal to 45 ⁇ m. This has the advantage that the powder of the base material (2) with a larger diameter of the powder body is less sensitive to unwanted oxygen uptake.
• the base material powder (2) before the filling and / or at least one of the components of the Attritors (4) before the evacuation plasma cleaned is cleaned.
• outgassing of the attritor takes place at a vacuum of 0.01 Pa (10 -4 mbar) to 0.1 Pa (10 -3 mbar) for a period of 0.5 h to 5 h and at a temperature in a range smaller equal to 400 ° C instead.
• This has the advantage that the oxygen contamination of the alloy constituents and / of the base material can be reduced or eliminated.
• organic and / or inorganic impurities can be reduced or eliminated with this purification.
• a further advantageous embodiment of the invention is at least one of the elements consisting of the group consisting of: Si, Y, Hf, Er, Gd, B, C, Zr, Y, Hf, Nb, Mo, W, Co, Cr and as alloying constituent V included.
• Atomic yttrium, atomic hafnium, and / or atomic zirconium form, with the (residual) oxygen, high-temperature-stable oxides that pinch the lattice dislocations in the metal matrix, thus improving creep resistance at high temperatures (even above 780 ° C).
• Atomic erbium and / or atomic gadolinium also form oxides which improve oxide resistance. This refers to the improved corrosion resistance of the target alloy (7) to oxygen. All listed metal oxides are finely distributed by mechanical alloying without forming coarse oxide particles.
• tungsten carbide is used to make the target alloy (7) correspondingly harder.
• the mechanical alloy components to be alloyed on a share in the base material powder (2) which also with over 0.5 at% may be present in the target alloy.
• the powder of the base material (2) may also have alloying constituents with a content which in the target alloy (7) is 0.5 at.%. This has the advantage that the accuracy of large amounts greater than or equal to 0.5 at% of alloy constituents can be better adjusted in the base material than via the subsequent mechanical alloying.
• the alloying ingredients with small amounts less than or equal to 0.5 at.% Are preferably added by mechanical alloying.
• the powder of the base material (2) contains, in addition to the main constituents, in particular Ti and Al, the following elements with the stated proportions and is formed of these - apart from unavoidable impurities: W: 0 to 8 at.%, C: 0 to 0, 6 at.%, Zr: 0 to 6 at.%, B: 0 to 0.2 at.%,
• Nb 4 to 25 at.%
• Mo 1 to 10 at.%
• Co 0.1 to 10 at.%
• Cr 0.5 to 3 at.%
• V 0.5 to 10 at .%.
• the target alloy (7) contains, in addition to the main constituents, in particular Ti and Al, the following elements with the stated proportions and is preferably formed of these - apart from unavoidable impurities: W: 0 to 8 at.%, Si: 0.2 to 0 , 35 at.%, C: 0 to 0.6 at.%, Zr: 0 to 6 at.%, Y: 0 to 1.5 at.%, Hf: 0 to 1.5 at.%, Er: 0 to 0.5 at.%, Gd: 0 to 0.5 at.%, B: 0 to 0.2 at.%,
• Nb 4 to 25 at.%
• Mo 1 to 10 at.%
• Co 0.1 to 10 at.%
• Cr 0.5 to 3 at.%
• V 0.5 to 10 at .%.
• the invention further relates to a device (4) for mechanical alloying of a high-temperature-resistant target alloy, which has an attritor container (1), an agitator (5) and at least one grinding ball (3). At least one of the components (2) of the attritor (4) made of the base material and / or at least one of the alloy components of the target alloy (7) comes into contact with a base material powder (2).
• the areas of the components which come into contact with the base material powder (2), in addition to the base material additionally contain only one of the alloy constituents of the target alloy (7), in addition to unavoidable impurities.
• the components of the attritor (4) include, in particular, an attritor container (1), a plurality of grinding balls (3) and / or the agitator (5) with a plurality of grinding arms. This offers the advantage that the other alloying constituents need not be added in powder form. In particular, this reduces the oxygen contamination.
• the attritor container (1), the grinding balls (3) and / or the grinding arms of the agitator (5) are actively used as a supplier of alloy components.
• evacuating the Attritor mattersers (1) can preferably be purged with inert gas, such as argon or helium to remove the residual oxygen.
• inert gas such as argon or helium to remove the residual oxygen.
• the filling of the attritor container (1) with the base material powder (2) preferably takes place under vacuum.
• At least the surface of the grinding balls (3) contains the base material and / or at least one of the alloy constituents of the target alloy (7).
• at least the inner walls of the attritor container (6) may include the base material and / or at least one of the alloy components comprising the target alloy (7).
• at least the surface of the grinding arms of the agitator (5) may include the base material and / or at least one of the alloying constituents comprising the target alloy (7).
• the components of the attritor (4) may be provided with a coating which include the base material and / or at least one of the alloying components.
• at least one component of the device for mechanical alloying (4) may completely consist of the base material and / or at least one of the alloy constituents, apart from unavoidable impurities.
• these are the grinding balls (3) and / or the grinding arms of the agitator (5).
• the attritor container (1) can be lined on the inside with interchangeable tiles, which represent the inner walls of the Attritor disposers (1). In turn, these tiles can be made entirely of the base material and / or of at least one of the alloy components, except for unavoidable impurities.
• the base material powder for example of Ti and Al and, for example, Cr, V, W, Mo, Fe, Co, Zr, C and / or B, is likewise plasma-cleaned under the same conditions and then filled into the attritor container (1).
• the Attritor (4) takes up about 5kg of powder.
• Both the grinding arms of the agitator (5) already located in the attritor container (1) preferably consist only of Ti, Al and only of the corresponding alloy constituents as well as the grinding balls (3).
• the grinding balls (3) have a diameter of about 2 cm.
• the grinding arms (5) and the grinding balls (3) are preferably formed of the solid material of an alloy similar or identical to the target alloy, so that not only the surface of the grinding balls (3) or the grinding arms (5) from the "target alloy" (7 ), but also the subsurface material.
• An alloy similar to the target alloy means that this similar alloy may not have any alloying constituents that are not present in the target alloy (7).
• the similar alloy may have less alloying constituents than the target alloy (7), whereby the proportions of the alloy constituents in the similar alloy to the target alloy (7) may be different.
• the attritor container (1) is filled with grinding balls (3) and then closed. At a speed of 100 rev / min is stirred for 5 hours.
• the mechanically alloyed powder (2) with the corresponding alloy constituents is then hot-isostatically pressed at 1200 ° C. for 3 hours under 2000 bar (200 MPa) in a helium protective gas atmosphere. This produces Hf, Y, Zr, Er and Gd oxides, which are finely distributed in the matrix.
• low pressure turbine (NDT) blades, NDT stators, and / or NDT disks may be made of such an alloy.
• hot gas flow sheets and / or other structural elements of a, transient or stationary, gas turbine may consist of such a target alloy (7).
• the above method can also be used for alloying other base materials.
• the base material of titanium and aluminum for example, be replaced by molybdenum, nickel or iron.
• the alloy components and proportions described above can be chosen to be identical for molybdenum, nickel or iron.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Optics & Photonics (AREA)
• Powder Metallurgy (AREA)
• Physical Vapour Deposition (AREA)
• Manufacture Of Metal Powder And Suspensions Thereof (AREA)

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• 2014
  • 2014-11-03 DE DE102014222347.4A patent/DE102014222347A1/de not_active Withdrawn
• 2015
  • 2015-09-23 EP EP15186417.0A patent/EP3015199A3/fr not_active Withdrawn
  • 2015-10-20 US US14/887,765 patent/US20160122850A1/en not_active Abandoned

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