Method for producing monocrystalline structures

• US 6,024,792 A
• Filed: 02/20/1998
• Issued: 02/15/2000
• Est. Priority Date: 02/24/1997
• Status: Expired due to Term

• Current Assignee: Oerlikon Metco AG (OC Oerlikon Corporation AG)
• Original Assignee: Sulzer Innotec AG (Sulzer AG)
• Inventors: Wagniere, Jean-Daniel, Kurz, Wilfried, Rusterholz, Hansjakob, Gaumann, Werner, Bieler, Hans-Werner
• Primary Examiner(s): HITESHEW, FELISA CARLA
• Application Number:
  US09/026,782
• Time in Patent Office: 725 Days
• Field of Search: 117/4, 117/7, 117/9, 117/903, 117/904, 117/905, 117/913
• US Class Current: 117/9
• CPC Class Codes: B22F 10/25 Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 10/368 Temperature or temperature gradient, e.g. temperature of the melt pool
• CPC Class Codes: B22F 10/38 to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
• CPC Class Codes: B22F 10/64 by thermal means control of energy beam parameters for post heating B22F10/364
• CPC Class Codes: B22F 12/17 to heat the build chamber or platform
• CPC Class Codes: B22F 12/41 characterised by the type, e.g. laser or electron beam
• CPC Class Codes: B22F 12/44 characterised by the configuration of the radiation means
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 2103/02 Iron or ferrous alloys
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/32 taking account of the properties of the material involved
• CPC Class Codes: B23K 26/34 Laser welding for purposes other than joining
• CPC Class Codes: B23K 35/004 at least one of the workpieces being of a metal of the iron group
• CPC Class Codes: B23K 35/30 with the principal constituent melting at less than 1550 degrees C
• CPC Class Codes: B23K 35/3033 Ni as the principal constituent
• CPC Class Codes: B23K 35/3046 Co as the principal constituent
• CPC Class Codes: C30B 11/00 : Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method C30B13/00, C30B15/00, C30B17/00, C30B19/00 take precedence; under a protective fluid C30B27/00
• CPC Class Codes: C30B 13/00 : Single-crystal growth by zone-melting; Refining by zone-melting C30B17/00 takes precedence; by changing the cross-section of the treated solid C30B15/00; under a protective fluid C30B27/00; for the growth of homogeneous polycrystalline material with defined structure C30B28/00
• CPC Class Codes: C30B 13/24 : using electromagnetic waves
• CPC Class Codes: C30B 29/52 : Alloys
• CPC Class Codes: Y02P 10/25 : Process efficiency
• CPC Class Codes: Y10S 117/904 : Laser beam
• CPC Class Codes: Y10S 4/904 : Swim-in-place pool

Abstract

In the method for manufacturing monocrystalline structures, parts or workpieces of metallic super-alloys on substrates with a monocrystalline structure or monocrystalline structures, the surface of the substrate is melted with an energy beam of high energy density from an energy source. The material which is to be introduced into the monocrystalline structure is supplied to the melted region of the substrate. The supplied material is completely melted. The energy input with the energy beam is regulated and/or controlled in such a manner that the speed of solidification and the temperature gradient lie in the dendritic crystalline region in the GV diagram, outside the globulitic region.

Claims

1. A method for producing monocrystalline structures, parts or workpieces of metallic super-alloys on substrates with a monocrystalline structure or monocrystalline structures characterized in that:

a surface of the substrate is melted with an energy beam of an energy source,

a material which is to be introduced into the monocrystalline structure is supplied to the melted region,

the material is completely melted, and

an energy input is regulated in such a manner that the rate of solidification and the temperature gradient lie in a dentritic crystalline region in the GV diagram and outside a globulitic region.

2. A method in accordance with claim 1 in which a laser beam, an electron beam or an arc is used as an energy beam of high energy density.

3. A method in accordance with claim 1 in which the material which is to be introduced into the monocrystalline structure is supplied in powder form or in the form of a wire.

4. A method in accordance with claim 1 in which the supplied material is the same as that of the substrate or

in which the supplied material is different and has a crystalline structure similar to that of the substrate.

5. A method in accordance with claim 1 in which at least one of the substrate and the material which is to be introduced into a monocrystalline structure is a metallic super-alloy on a Co basis or on a Fe basis or on a Ni basis, such as CMSX-4.

6. A method in accordance with claim 1 in which the substrate is preheated to a preheating temperature, preferably in the temperature range from 800°

C. to 1000°

C., with the preheating temperature preferably being held constant during the production of the epitaxial layer.

7. A method in accordance with claim 6 in which the preheating of the substrate is carried out inductively.

8. A method in accordance with claim 1 in which the crystalline structure produced is subsequently annealed to low internal stresses preferably at a temperature in the range from 1000°

C. to 1250°

C., preferably at about 1150°

C.

9. A method in accordance with claim 1 which is carried out under protective gas or in a vacuum, with the protective gas preferably flowing laminarly or largely laminarly in the region of the process.

10. Use of the method in accordance with claim 1 for supplementing the monocrystalline structure of a worn monocrystalline turbine blade, in particular of a rotor blade of a gas turbine or of an airplane engine.

11. A method for producing a microcrystalline structure of a metallic super-alloy on a surface of a substrate comprising the steps of:

melting a region of the surface of the substrate with an energy beam from an energy source;

supplying a material to be introduced into the monocrystalline structure to the surface region where the substrate is melted;

completely melting the material; and

controlling an energy input by the beam to the material so that a rate of solidification and a temperature gradient lie in a dentritic crystalline region in a GV diagram and outside a globulitic region.

12. A method for supplementing a monocrystalline structure of a worn portion of a monocrystalline turbine blade, the method comprising the steps of:

melting a region of a surface of the substrate with an energy beam from an energy source;

supplying a material to be introduced into the monocrystalline structure to the surface region where the substrate is melted;

completely melting the material; and

controlling an energy input by the beam to the material so that a rate of solidification and a temperature gradient lie in a dentritic crystalline region in a GV diagram and outside a globulitic region.