Patent Grant
11559847
The disclosure relates generally to industrial machine part repair or manufacture, and more particularly, to superalloy parts having circular cross-sectional openings on an external surface.
Hard-to-weld (HTW) alloys, such as nickel-based superalloys and certain aluminum-titanium alloys, due to their gamma prime and various geometric constraints, are difficult to join when the gamma prime phase is present in volume fractions greater than about 30%, which may occur when aluminum or titanium content exceeds about 3%. As used herein, an “HTW alloy” is an alloy which exhibits liquation, hot and strain-age cracking, and which is therefore impractical to weld.
Non-weldable (NW) alloys are typically precipitation hardenable or solid-solution strengthened alloys which cannot be practically welded in an industrial setting and at an industrial scale, are only weldable under prohibitively extreme conditions, and, as such, are generally regarded as not being weldable. As used herein, an “NW alloy” refers to alloys having titanium-aluminum equivalents (or combined percentages of composition, by weight) of about 4.5 or higher. NW alloys may include nickel-based alloys in which the primary hardening mechanism is via the process of precipitation, cobalt alloys which are solid solution strengthened, and alloys which require heating immediately prior to and during welding to at least about 1,000 degrees Celsius (° C.).
These HTW and NW alloys may be incorporated into components of gas turbine engines such as airfoils, blades (buckets), nozzles (vanes), shrouds, combustion parts, transitions pieces and other hot gas path (HGP) components. Incorporation of HTW and NW alloys may be desirable due to their often superior operational properties, particularly for certain components subjected to the most extreme conditions and stresses. However, the poor weldability inherent in HTW and NW alloys complicates servicing and repairing components incorporating these alloys.
Industrial machine parts such as airfoils, blades (buckets), nozzles (vanes), shrouds, combustion parts, transitions pieces, and other hot gas path components may have hundreds or thousands of cooling holes that provide fluid flow paths. HGP components in turbomachinery such as turbine blades and nozzles, are exposed to extreme stresses and environment. Occasionally, the machine part can have too many cooling holes, or the cooling holes are in the wrong location or the cooling holes are oversized. These machine parts need to be serviced to eliminate the improperly machined holes. Advances in turbomachinery technology, however, have led to the use of more advanced materials such as superalloys like high gamma prime superalloys, which cannot be repaired using conventional techniques.
Repairs of improperly machined holes in components typically involve positioning a plug with the proper diameter to fit the hole. The process presents a number of challenges. First, the plug must match the diameter of the improperly machined hole. Thus, the plug must be machined after measurement of the diameter of the improperly machined hole to match the size of the hole. Further, there must be a gap between the component and plug to ensure proper brazing. In addition, if the plug is inserted vertically, the plug may drop out. Alternatively, if the plug is inserted horizontally, there is no gap between the plug and the component. There is no guarantee the one braze cycle can fix the improperly machined hole. The plug may move during the brazing process and rework may be required due to voids, lack of braze, over flow, etc. This situation creates an unacceptably long repair cycle.
A first aspect of the disclosure provides a method including positioning a plug having an inner braze element coupled thereto into a cavity defined by an internal surface of a component. The cavity has a circular cross-section at the external surface of the component. The plug completely fills the circular cross-section and the inner braze element is within the cavity. The method includes positioning a braze paste at least partially around the plug at the external surface. The method includes positioning the component such that the inner braze element is above the plug. The component is subjected to a thermal cycle to melt the inner braze element around the plug, completely sealing the cavity by forming a metallurgical bond with the plug and the internal surface of the component.
A second aspect of the disclosure provides a component including a body including a first material, wherein the body includes an external surface. The component includes a second material on the external surface completely covering a circular cross-section on the external surface. The component includes a braze material bonded with the first material and the second material on an internal surface defining a cavity within the body.
A third aspect of the disclosure provides a method including positioning a plug having a pre-sintered preform (PSP) coupled thereto into a cavity defined by an internal surface of a superalloy component. The cavity has a circular cross-section at the external surface of the superalloy component. The plug completely fills the circular cross-section and the PSP is within the cavity. The method includes positioning a braze paste at least partially around the plug at the external surface of the superalloy component. The method includes positioning the superalloy component such that the PSP above the plug. The superalloy component is subjected to a thermal cycle to melt the PSP around the plug, completely sealing the cavity by forming a metallurgical bond with the plug and the internal surface of the superalloy component.
The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.
These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings.
As an initial matter, in order to clearly describe the current disclosure it will become necessary to select certain terminology when referring to and describing relevant machine components within a gas turbine. When doing this, if possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. Unless otherwise stated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different or overlapping terms. What may be described herein as being a single part may include and be referenced in another context as consisting of multiple components. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part.
In operation, air flows through compressor 102 and compressed air is supplied to combustor 104. Specifically, the compressed air is supplied to fuel nozzle assembly 108 that is integral to combustor 104. Fuel nozzle assembly 108 is in flow communication with combustion region 106. Fuel nozzle assembly 108 is also in fluid communication with a fuel source (not shown in
The components shown in
Embodiments of the disclosure provide a brazing process which overcomes the deficiencies noted above. The method begins with a component having a cavity that needs to be filled. The cavity has a circular cross-section at the external surface of the component. The method includes positioning a plug having an inner brazing element attached thereto. The plug is positioned onto a cavity of a component completely covering the circular cross-section at the external surface. The inner brazing element is within the cavity. A braze paste is applied around the plug at the external surface. The component is positioned with the inner brazing element above the plug and the component is subjected to a thermal cycle to melt the inner brazing element around the plug, completely sealing the cavity by forming a metallurgical bond with the plug and the internal surface of the component. The braze paste forms a metallurgical bond with the plug and the external surface during the thermal cycle. A more detailed description is provided below.
As used herein, “superalloy” refers to an alloy having numerous excellent physical characteristics compared to conventional alloys, such as but not limited to: high mechanical strength, high thermal creep deformation resistance, high corrosion or oxidation resistance, and good surface stability. Superalloy examples may include but are not limited to: Rene alloys like Rene 108, CM247, Hastelloy, Waspaloy, Haynes alloys, Inconel, Incoloy, MP98T, TMS alloys, CMSX single crystal alloys. In an embodiment, superalloys for which teachings of the disclosure may be especially advantageous are those superalloys having a high gamma prime (γ′) value. “Gamma prime” (γ′) is the primary strengthening phase in nickel-based alloys. Examples of high gamma prime superalloys include but are not limited to: Rene 108, N5, GTD 444, MarM 247 and IN 738.
In embodiments, the inner braze element 52 may be a braze ball (
Inner braze element 52 may include braze materials such as nickel-based filler metals. Examples of such braze materials include BNi-2, BNi-5, BNi-9, DF4B, D15 or high melt/low melt mixtures, for example, MarM 247/D15 in a 50/50 ratio.
In embodiments, inner braze element 52 may be a pre-sintered preform (PSP). A PSP may be, but is not limited to, a mixture of a first material having a first melting point and a second material having a second melting point, the first melting point being lower than the second melting point. The mixture is at any suitable ratio for providing desired properties. Suitable ratios for the mixture may include, but are not limited to, between about 40% and about 95% being the first material; between about 50% and about 80% being the first material; between about 5% and about 60% being the second material; between about 20% and about 50% being the second material, about 50% being the first material; about 50% being the second material; about 20% being the second material; about 80% being the first material, or any suitable combination, sub-combination, range, or sub-range therein.
In an embodiment, the first material is considered as a high-melt material and the first melting point is above about 1300° C. In an embodiment, the second material is considered as a low-melt material and the second melting point, for example, between about 870° C. and about 1260° C.
A suitable high-melt material for the PSP has a composition, by weight, of between about 13.7% and about 14.3% chromium (Cr), between about 9% and about 10% cobalt (Co), between about 2.8% and about 3.2% aluminum (Al), between about 4.7% and about 5.1% titanium (Ti), between about 3.5% and about 4.1% tungsten (W), between about 1.4% and about 1.7% molybdenum (Mo), between about 2.4% and about 3.1% tantalum (Ta), up to about 0.12% carbon (C) (for example, between about 0.08% and about 0.12%), up to about 0.04% zirconium (Zr), up to about 0.02% boron (B) (for example, between about 0.005% and about 0.020%), up to about 0.35% iron (Fe) up to about 0.3% Si, up to about 0.1% manganese (Mn), up to about 0.1% copper (Cu), up to about 0.015% phosphorus (P), up to about 0.005% sulfur (S), up to about 0.15% niobium (Nb), and a balance of nickel.
Another suitable high-melt material for the PSP has a composition, by weight, of between about 8.0% and about 8.7% Cr, between about 9% and about 10% Co, between about 5.25% and about 5.75% Al, up to about 0.9% Ti (for example, between about 0.6% and about 0.9%), between about 9.3% and about 9.7% W, up to about 0.6% Mo (for example, between about 0.4% and about 0.6%), between about 2.8% and about 3.3% Ta, between about 1.3% and about 1.7% hafnium (Hf), up to about 0.1% C (for example, between about 0.07% and about 0.1%), up to about 0.02% Zr (for example, between about 0.005% and about 0.02%), up to about 0.02% B (for example, between about 0.01% and about 0.02%), up to about 0.2% Fe, up to about 0.06% silicon (Si), up to about 0.1% Mn, up to about 0.1% Cu, up to about 0.01% P, up to about 0.004% S, up to about 0.1% Nb, and a balance of nickel.
Another suitable high-melt material for the PSP has a composition, by weight, of between about 13.7% and about 14.3% Cr, between about 9% and about 10% Co, between about 2.8% and about 3.2% Al, between about 4.8% and about 5.2% Ti, between about 3.7% and about 4.3% W, between about 3.7% and about 4.3% Mo, up to about 0.1% rhenium (Re) (with Re and W being less than about 4.3%), up to about 0.1% Ta, up to about 0.1% Hf, up to about 0.19% C (for example, between about 0.15% and about 0.19%), up to about 0.15% Pd, up to about 0.3% Pt, up to about 0.01% Mg, up to about 0.1% Zr (for example, between about 0.02% and about 0.1%), up to about 0.02% B (for example, between about 0.01% and about 0.02%), up to about 0.35% Fe, up to about 0.1% Si, up to about 0.1% Mn, up to about 0.015% P, up to about 0.0075% S, up to about 0.1% Nb, and a balance of nickel.
Another suitable high-melt material for the PSP has a composition, by weight, of between about 6.6% and about 7% Cr, between about 11.45% and about 12.05% Co, between about 5.94% and about 6.3% Al, up to about 0.02% Ti, between about 4.7% and about 5.1% W, between about 1.3% and about 1.7% Mo, between about 2.6% and about 3% Re, between about 6.2% and about 6.5% Ta, between about 1.3% and about 1.7% Hf, up to about 0.14% C (for example, between about 0.1% and about 0.14%), up to about 0.3% platinum (Pt), up to about 0.0035% magnesium (Mg), up to about 0.03% Zr, up to about 0.02% B (for example, between about 0.01% and about 0.02%), up to about 0.2% Fe, up to about 0.06% Si, up to about 0.1% Mn, up to about 0.01% P, up to about 0.004% S, up to about 0.1% Nb, and a balance of nickel.
Another suitable high-melt material for the PSP has a composition, by weight, of between about 16.5% and about 18.5% Cr, between about 27% and about 30% Mo, about 1.5% Ni, up to about 0.08% C, about 1.5% Fe, between about 3% and about 3.8% Si, up to about 0.03% P, up to about 0.03% S, up to about 0.15% oxygen (O), and a balance of cobalt.
A suitable low-melt material for the PSP has a composition, by weight, of between about 22.5% and about 24.25% Cr, up to about 0.3% Ti (for example, between about 0.15% and about 0.3%), between about 6.5% and about 7.5% W, between about 9% and about 11% nickel (Ni), between about 3% and about 4% Ta, up to about 0.65% C (for example, between about 0.55% and about 0.65%), between about 2% and about 3% B, about 1.3% Fe, up to about 0.4% Si, up to about 0.1% Mn, up to about 0.02% S, and a balance of cobalt.
Another suitable low-melt material for the PSP has a composition, by weight, of about 14% Cr, about 10% Co, about 3.5% Al, about 2.75% B, between about 2.5% and about 2.75% Ta, up to about 0.1% yttrium (Y), and a balance of nickel.
Another suitable low-melt material for the PSP has a composition, by weight, of about 14% Cr, about 9% Co, about 4% Al, about 2.5% B, and a balance of nickel.
Another suitable low-melt material for the PSP has a composition, by weight, of about 15.3% Cr, about 10.3% Co, about 3.5% Ta, about 3.5% Al, about 2.3% B, and a balance of nickel.
Another suitable low-melt material for the PSP has a composition, by weight, of about 15.3% Cr, about 10.3% Co, about 3.5% Ta, about 3.5% Al, about 2.3% B, and a balance of nickel.
In
Braze paste 56 may be applied on exterior surface 42 of component 40 as shown in
In an embodiment, braze paste 56 contains metals containing either boron (B) or silicon (Si) (or a combination of both). In embodiments, braze past 56 may contain superalloy powder as a filler.
As shown in
The brazing process or thermal cycle occurs at the braze temperature, which is based upon the materials of inner braze element 52 melting and/or fusing to interior surface 44 and the plug 50. In embodiments, with inner braze element 52 being a nickel-based braze alloy, the brazing application temperature is between about 871° C. and 1260° C.
As shown in
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. “Approximately” as applied to a particular value of a range applies to both values, and unless otherwise dependent on the precision of the instrument measuring the value, may indicate +/−10% of the stated value(s).
The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3487530 | Ely | Jan 1970 | A |
| 6199746 | Dupree | Mar 2001 | B1 |
| 6454156 | Taras, Jr. | Sep 2002 | B1 |
| 8087565 | Kottilingam | Jan 2012 | B2 |
| 8356409 | Perret | Jan 2013 | B2 |
| 8572949 | Wirth | Nov 2013 | B2 |
| 9056443 | Schick | Jun 2015 | B2 |
| 9765623 | Kottilingam | Sep 2017 | B2 |
| 9863249 | Shinn et al. | Jan 2018 | B2 |
| 20030034379 | Jackson | Feb 2003 | A1 |
| 20080166233 | Johnson | Jul 2008 | A1 |
| 20130086785 | Cui | Apr 2013 | A1 |
| 20160281482 | Nguyen et al. | Sep 2016 | A1 |
| 20170044903 | Kottilingam | Feb 2017 | A1 |
| 20180161902 | Cui | Jun 2018 | A1 |
| Number | Date | Country |
|---|---|---|
| 113090336 | Jul 2021 | CN |
| 1867423 | Dec 2007 | EP |
| 2492044 | Aug 2012 | EP |
| 3305464 | Apr 2018 | EP |
| 3848142 | Jul 2021 | EP |
| 2021109240 | Aug 2021 | JP |
| Entry |
|---|
| EP Search Report and for corresponding EP Application No. 20216762.3 dated May 28, 2021, 6 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20210205910 A1 | Jul 2021 | US |
