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
• • 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
• • 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

Definitions

• Beta-titanium alloys with high vanadium contents are characterized by good strength and at the same time good toughness and ductility. They are usually processed in a thermoforming process into semi-finished products, such as sheets, rods, hollow or solid sections, wires, from which then high-quality lightweight components are produced.
• beta titanium alloys generally contain V, Nb, Ta, Mo, Fe and Cr as the main alloying elements stabilizing the Krz ⁇ mixed crystal, as well as certain contents of Zr, Sn, Al and additions of Si.
• a beta titanium alloy and a method for producing components made of this alloy are also known from DD 281 422 A5 known.
• the contents of Cr and V are in total 1.5 to 4.5 mass%.
• the content of Cr is limited to less than 2.5 mass%.
• the known alloy contains less than 2.0 mass% Fe, 3.8-4.8 mass% Al, 1.5-4.5 mass% Mo and 1.5-2.5 mass% Sn , 2.8-4.8 mass% Zr and less than 0.3 mass% Si.
• a melt of this type is cast into ingots, which are then thermoformed into a component in a two-stage process.
• the obtained component is subjected to a heat treatment in which its temperature is 10 ° C to 40 ° C under a in the DD 281 422 A5 held "transus ⁇ " real value, brought into solid solution. After this heat treatment, the part is held between 550 ° C to 650 ° C for four to twelve hours.
• the parts thus treated have a yield strength R p0.2 of at least 1100 MPa and a tensile strength R m of at least 1200 MPa.
• beta titanium alloys are in the AT-PS 272 677 , of the EP 0 408 313 B1 and the EP 0 600 -579 B1 given.
• Common to the prior art documented in these documents is the desire to provide a titanium alloy which is as cast as possible, which at the same time has good mechanical properties and can be produced cost-effectively.
• the invention therefore an object of the invention to provide a high-strength beta-titanium alloy with good plastic properties before curing for the purpose of good formability and high fatigue strength after curing, which can be produced inexpensively.
• a procedure should be specified become, with which from such an alloy heavy-duty components can be produced inexpensively.
• this object is achieved by a beta titanium alloy containing (in% by mass) V: 10-17%, Fe: 2-5%, Al: 2-5%, Mo: 0.1-3 %, and optionally one or more alloying elements from the group Sn, Si, Cr, Nb, Zr according to the following proviso: Sn: 0.1-3%, Si: 0.1 ⁇ 2%, Cr: ⁇ 2%, Nb: ⁇ 2%, Zr: ⁇ 2, and the remainder contains Ti and unavoidable impurities.
• a beta-titanium alloy composed according to the invention certainly achieves a yield strength R p0.2 of at least 1400 MPa, a tensile strength R m of at least 1500 MPa and a plastic strain ⁇ p0.2 of more than 4%.
• Their density ⁇ does not exceed 4.8 g / cm 3 , so that not only extremely solid but also weight-optimized components can be produced with a beta titanium alloy according to the invention.
• the alloy according to the invention has vanadium contents which are markedly higher than those provided in the prior art in beta titanium alloys.
• the high V contents stabilize the ⁇ -phase of the microstructure and increase the heat resistance. Therefore, the V content in an alloy according to the invention is preferably in the range of 12-17% by mass, in particular in the range of 13-17% by mass.
• the effect of the iron in the composite titanium alloy according to the invention consists in a stabilization of the ⁇ -phase of the structure, an increase in the heat resistance and an improvement of the mixed crystal formation.
• Molybdenum in contents of 0.1 to 3 mass%, preferably at least 0.5 mass%, is contained in a titanium material according to the invention in order to stabilize the ⁇ -phase of the microstructure and to increase the heat resistance.
• a beta titanium alloy according to the invention additionally contains one or more alloying elements from the group Sn, Si, Cr, Nb, Zr.
• the Sn contents are preferably in the range of 0.5 to 3 mass%.
• Silicon increases the heat resistance and the oxidation resistance in an alloy according to the invention.
• Chromium can be added to the alloy to stabilize the ⁇ -phase of the microstructure and increase the heat resistance.
• niobium has a favorable influence on the heat resistance and the oxidation resistance of the alloy.
• the alloy according to the invention may contain further constituents, as long as they do not adversely affect the properties achieved according to the invention.
• contents of carbon and contents of elements belonging to the group of lanthanides are to be mentioned in this connection.
• Optimum properties of the beta-titanium alloys according to the invention are obtained when the above-mentioned limit values are exactly adhered to at least two decimal places.
• the hot forming can be performed for the production of strips or sheets as hot rolls, which can be followed, if necessary, a reel.
• the Ti alloy according to the invention can be produced particularly cost-effectively by alloying the alloying elements V, Fe and Al in a manner known per se not individually but in the form of a master alloy.
• Such master alloys are commercially available.
• the hot end product obtained by the process according to the invention after thermoforming consists of single-phase, metastable beta titanium whose transus temperature T B is about 788 ° C.
• T B transus temperature
• the hot end product is produced by hot rolling, it has stretched crystals in the rolling direction and has a partially dynamically recrystallized structure.
• V acuum A rc R emelt - Oven acuum A rc R emelt - Oven
• the precursor can be, for example, round blocks, which are then hot-formed in the course of hot forming into billets or blanks.
• Billets of this type are typically square-shaped with edge lengths of, for example, 70 mm or round with a diameter of, for example, 60 mm.
• Hot-end forming is typically performed at forming temperatures that range from 950 ° C to 1150 ° C to provide effective Cross-section reduction and a homogenization of the composition and the structure to achieve.
• the hot forming is carried out as hot rolling, provides an advantageous embodiment of the method according to the invention that the final product is solution-annealed after the final heat deformation.
• the solution annealing is followed by cold forming.
• Solution annealing is typically carried out at 875 ° C for 30 minutes.
• the optionally solution-annealed final product is subjected to recrystallization annealing.
• the temperatures during this annealing treatment are typically in the range of 775 ° C to 875 ° C with hold times of 20 to 40 minutes.
• the final product obtained after cold working has a yield strength R p0.2 of at least 870 MPa to 900 MPa, a tensile strength R m which is 890 MPa to 944 MPa, and a plastic elongation of 14-17%.
• the product obtained has a yield strength R p0.2 of at least 1400 MPa, a yield strength R m of at least 1500 MPa and an elongation ⁇ p1 of at least 4%.
• the typical temperature of the curing treatment is about 480 ° C. In compliance with these time and temperature specifications, an optimal range of properties of the end products according to the invention is established.
• semi-finished products such as blanks, sheets, rods, profiles or wires can be produced, which, because of their property profile, are outstandingly suitable for components which are highly resilient.
• the semi-finished products can be produced inexpensively, in particular by using the method according to the invention.
• Beta-titanium alloys according to the invention prove to be particularly suitable as a construction material for the production of components used in rail-bound or road-bound vehicles as well as in the aerospace industry.
• axle springs, connecting rods, piston pins, high-strength screws, brake pistons and discs are mentioned.
• beta-titanium alloys according to the invention due to their special properties, are particularly suitable for the production of components used in the field of general mechanical engineering, apparatus engineering, plant engineering, container construction, cryogenics, vehicle construction or sports.
• beta-titanium alloys according to the invention are particularly suitable for the production of components which are used in the temperature range of -196 ° C to 300 ° C.
• the billets are hot rolled into wire at hot rolling temperatures ranging from 1100 ° C to 950 ° C, and then coiled into coils.
• the wire had single-phase metastable ⁇ -titanium (transus temperature T ⁇ about 788 ° C.) with crystallites stretched in the direction of the wire axis and partially dynamically recrystallized microstructure.
• the wire was solution annealed at 875 ° C for 30 minutes. After the solution annealing the cold forming of the wire took place. After cold working, the wire was recrystallized at temperatures ranging from 775 ° C to 875 ° C with a holding period ranging from 20 minutes to 40 minutes.
• the as-annealed wire had a yield strength R p0.2 between 870 MPa and 900 MPa, a tensile strength R m between 890 MPa - 944 MPa, and an elongation A between 14% -17 %.
• the recrystallization annealing was followed by a curing treatment in which the wire was held at 480 ° C for 5 hours.
• the thus finished wire had at room temperature a yield strength R p0.2 of more than 1400 MPa, a tensile strength R m of more than 1500 MPa and an elongation A which was at least in the range of 4% to 5%.

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• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Metallurgy (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Forging (AREA)
• Metal Rolling (AREA)
• Silicon Compounds (AREA)
• Heat Treatment Of Nonferrous Metals Or Alloys (AREA)
• Heat Treatment Of Articles (AREA)
• Conductive Materials (AREA)

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• 2003
  • 2003-07-03 DE DE10329899A patent/DE10329899B8/de not_active Expired - Fee Related
• 2004
  • 2004-07-02 CN CNB2004800190087A patent/CN100478472C/zh not_active Expired - Fee Related
  • 2004-07-02 US US10/560,977 patent/US20070175552A1/en not_active Abandoned
  • 2004-07-02 AT AT04740562T patent/ATE398686T1/de not_active IP Right Cessation
  • 2004-07-02 DE DE502004007396T patent/DE502004007396D1/de active Active
  • 2004-07-02 JP JP2006518094A patent/JP2007527466A/ja active Pending
  • 2004-07-02 KR KR1020067000188A patent/KR20060111895A/ko not_active Application Discontinuation
  • 2004-07-02 EP EP04740562A patent/EP1641950B1/de not_active Not-in-force
  • 2004-07-02 WO PCT/EP2004/007201 patent/WO2005003399A1/de active IP Right Grant
• 2005
  • 2005-12-19 ZA ZA200510297A patent/ZA200510297B/en unknown

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