Brazing tape having a central region containing a low melting temperature alloy material and a high melting temperature alloy material, and related methods

Abstract

A brazing tape having a central region including a low melting temperature alloy material and a high melting temperature alloy material, and an associated method, are provided. The brazing tape (100) includes a first portion (112), a second portion (114), and a central portion (116) located between and adjacent to the first and second portions. The first portion (112) includes a first alloy material having a first melting temperature, and the second portion (114) includes a second alloy material having a second melting temperature, the second melting temperature being higher than the first melting temperature. The central portion (116) includes a mixture of the first alloy material and the second alloy material. The material composition of the central portion can be gradually changed from the first alloy material to the second alloy material. Related methods are also disclosed.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to the repair of industrial parts. More specifically, the present disclosure relates to a brazing tape having a central region including a low melting temperature material and a high melting temperature material, and related methods for repairing industrial parts. [Background technology]

[0002] Industrial components, such as hot-gas path components in gas turbine systems, typically require repair after a period of use. In some cases, deep and / or shaped openings in components, such as turbine nozzles or blade airfoils, caused by, for example, fill erosion and / or oxidation, must be refilled with material to near-net shape tolerances. In certain cases, these openings can be greater than 2.5 millimeters (mm) deep and have a variety of irregular shapes. Typically, brazing tapes or pre-sintered preforms (PSPs) are used to repair damage to such openings and / or shaped surfaces of components. Brazing tapes are advantageous due to their flexibility and ability to fill irregular shapes. Brazing tapes comprise a homogeneous mixture of particulate components as a single layer or individual layers of a single homogeneous material. These brazing tapes provide near-net-shape surfaces for difficult-to-shape openings or contours and also have limited ability to withstand finishing processes. For example, finishing can remove the homogeneous, harder outer layer of brazing tape material needed for the part's surface, exposing another homogeneous layer of brazing tape designed for adhesion to the part but unsuitable for the part's surface. This limits the applicability of brazing tape. Pre-sintered preforms offer a similar layer of material and present the same challenges as brazing tape. Furthermore, the layers of PSP are bonded together and rigid. As a result, PSP is more difficult to use with irregularly shaped openings and contours in parts. Summary of the Invention

[0003] All aspects, examples, and features described below can be combined in any technically possible manner.

[0004] One aspect of the present disclosure provides a brazing tape comprising a first portion, a second portion, and a central portion located between the first portion and the second portion and adjacent to the first portion and the second portion, wherein the first portion includes a first alloy material having a first melting temperature, the second portion includes a second alloy material having a second melting temperature, the second melting temperature being higher than the first melting temperature, and the central portion includes a mixture of the first alloy material and the second alloy material, wherein the first alloy material may hereinafter be referred to as a low melting temperature alloy material, and the second alloy material may hereinafter be referred to as a high melting temperature alloy material.

[0005] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first portion consists solely of low melting temperature alloy material.

[0006] Another aspect of the present disclosure includes any of the preceding aspects, wherein the second portion consists solely of high melting temperature alloy material.

[0007] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first portion consists solely of the low melting temperature alloy material and the second portion consists solely of the high melting temperature alloy material.

[0008] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes the low melting temperature alloy material in a lower concentration than the high melting temperature alloy material near the interface between the central portion and the second portion.

[0009] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes a higher concentration of the low melting temperature alloy material near the interface between the central portion and the first portion than the high melting temperature alloy material.

[0010] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the ratio of low melting temperature alloy material to high melting temperature alloy material varies according to a gradient along the thickness of the central portion.

[0011] Another embodiment of the present disclosure includes any of the aforementioned embodiments, wherein the slope is one of a substantially linear slope, a substantially logarithmic slope, a positive or negative slope, and a step slope.

[0012] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the brazing tape has a higher porosity in the first portion than in the second portion.

[0013] Another embodiment of the present disclosure includes any of the preceding embodiments, wherein the porosity of the second portion is less than the porosity of the first portion, and the porosity of the central portion is less than the porosity of the first portion and greater than the porosity of the second portion.

[0014] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the brazing tape further includes a side portion continuous with the second portion and including the high melting temperature alloy material, the side portion extending along an end of the central portion and an end of the first portion.

[0015] Another embodiment of the present disclosure includes any of the preceding embodiments, wherein the central portion comprises 90% or more of the thickness of the brazing tape.

[0016] Another aspect of the present disclosure includes any of the preceding aspects, wherein the brazing tape is flexible.

[0017] Another aspect of the present disclosure includes a brazing tape comprising a first low melting temperature alloy material portion consisting solely of a low melting temperature alloy material, a second high melting temperature alloy material portion consisting solely of a high melting temperature alloy material, and a central portion located between the first low melting temperature alloy material portion and the second high melting temperature alloy material portion and adjacent to the first low melting temperature alloy material portion and the second high melting temperature alloy material portion, wherein the central portion comprises a mixture of low melting temperature alloy material and high melting temperature alloy material, and the ratio of low melting temperature alloy material to high melting temperature alloy material varies according to a gradient along the thickness of the central portion.

[0018] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes the low melting temperature alloy material in a lower concentration than the high melting temperature alloy material near the interface between the central portion and the second portion.

[0019] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes a higher concentration of the low melting temperature alloy material near the interface between the central portion and the first portion than the high melting temperature alloy material.

[0020] Another aspect of the present disclosure includes any of the preceding aspects, wherein the brazing tape is flexible.

[0021] Another aspect of the present disclosure includes a method of repairing a component, the method including: placing a brazing tape on a substrate of the component, the brazing tape having a first portion, a second portion, and a central portion located between the first portion and the second portion, the first portion being positioned in contact with the substrate; and brazing the brazing tape to the substrate, the first portion including a low-melting temperature alloy material, the second portion including a high-melting temperature alloy material, and the central portion including a mixture of the low-melting temperature alloy material and the high-melting temperature alloy material, wherein the ratio of the low-melting temperature alloy material to the high-melting temperature alloy material varies according to a gradient along a thickness of the central portion; and brazing the brazing tape by heating the brazing tape to a temperature below the melting temperature of the high-melting temperature alloy material.

[0022] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first portion consists solely of low melting temperature alloy material.

[0023] Another aspect of the present disclosure includes any of the preceding aspects, wherein the second portion consists solely of high melting temperature alloy material.

[0024] Another aspect of the present disclosure includes any of the preceding aspects, wherein the first portion consists solely of the low melting temperature alloy material and the second portion consists solely of the high melting temperature alloy material.

[0025] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes the low melting temperature alloy material in a lower concentration than the high melting temperature alloy material near the interface between the central portion and the second portion.

[0026] Another aspect of the present disclosure includes any of the aforementioned aspects, wherein the central portion includes a higher concentration of the low melting temperature alloy material near the interface between the central portion and the first portion than the high melting temperature alloy material.

[0027] Another aspect of the present disclosure includes any of the preceding aspects, wherein the brazing tape is flexible.

[0028] Two or more aspects described in this disclosure, including those described in this summary section, may be combined to form implementations not specifically described herein, i.e., all embodiments described herein can be combined with each other.

[0029] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description and drawings, and from the claims.

[0030] These and other features of the present 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 illustrating various embodiments of the present disclosure. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic cross-sectional view of a brazing tape according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view of a brazing tape according to another embodiment of the present disclosure. [Figure 3] FIG. 10 is a schematic cross-sectional view of a brazing tape according to an additional embodiment of the present disclosure. [Figure 4] FIG. 2 is a schematic cross-sectional view of a brazing tape according to a further embodiment of the present disclosure. [Figure 5] FIG. 2 is a schematic cross-sectional view of a brazing tape according to another embodiment of the present disclosure. [Figure 6] 1 is a schematic cross-sectional view of a brazing tape according to an embodiment of the present disclosure. [Figure 7] FIG. 10 is a schematic cross-sectional view of a brazing tape according to an additional embodiment of the present disclosure. [Figure 8] 1 is a schematic cross-sectional view of a method for repairing a component using brazing tape according to an embodiment of the present disclosure. [Figure 9] 1 is a schematic cross-sectional view of a method for repairing a component using brazing tape according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0032] It should be noted that the drawings of the present disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the disclosure and therefore should not be considered limiting of the scope of the disclosure. In the drawings, like reference numerals represent like elements between the drawings.

[0033] Additionally, multiple descriptive terms may be used periodically herein, and it will prove useful to define these terms at the beginning of this section. These terms and their definitions are as follows, unless otherwise noted. The terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to denote the location or importance of the individual components. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that the terms “comprises” and / or “comprising,” as used herein, 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 a subsequently described event may or may not occur, or a subsequently described feature may or may not be present, and the description is meant to include instances where the event occurs or the feature is present, as well as instances where the event does not occur or the feature is not present.

[0034] When an element or layer is referred to as "on," "engaged to," "connected to," "coupled," or "attached to" another element or layer, the element or layer may be directly on, engaged with, connected to, coupled to, or attached to the other element or layer, or intervening elements or layers may be present. Conversely, when an element is referred to as "directly on," "directly engaged with," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The verb forms of "couple" and "attach" may be used interchangeably herein.

[0035] Embodiments of the present disclosure include a brazing tape and related methods. The brazing tape includes a first portion, a second portion, and a central portion located between and adjacent to the first and second portions. The first portion includes a low-melting-temperature alloy material, the second portion includes a high-melting-temperature alloy material, and the central portion includes a mixture of the low-melting-temperature and high-melting-temperature alloy materials. The central portion may have a gradual transition between the low-melting-temperature and high-melting-temperature alloy materials. The brazing tape is applicable to a wider range of repairs than conventional brazing tapes and PSPs, for example, difficult-to-fill erosion and / or oxidation on the molded sidewalls of internal gas turbine components. The low-melting-temperature alloy material on the first portion that contacts the component ensures adhesion and filling of irregular shapes. Because the central portion includes a high-melting-temperature alloy material, finishing operations that reach the central portion still leave the necessary high-melting-temperature alloy material on the surface of the component.

[0036] 1-7 show schematic cross-sectional views of a brazing tape 100 according to various embodiments of the present disclosure. As described herein, the brazing tape 100 can be used to repair a component 102 (FIGS. 8-9) using methods according to embodiments of the present disclosure.

[0037] The brazing tape 100 includes a first portion 112, a second portion 114, and a central portion 116. The central portion 116 is located between and adjacent to each of the first portion 112 and the second portion 114.

[0038] In certain embodiments, first portion 112 includes a low-melting temperature alloy material. In other embodiments, first portion 112 consists solely of a low-melting temperature alloy material. Low-melting temperature materials (hereinafter "LMTA materials") may include, but are not limited to, DF4B, B1P, AMS4782, D15, BNi-9, BNi-5, B93, and the like. First portion 112 may also be referred to as a first LMTA material portion.

[0039] In certain embodiments, second portion 114 includes a high-melting temperature alloy material. In other embodiments, second portion 114 consists solely of a high-melting temperature alloy material. Furthermore, in certain embodiments, first portion 112 consists solely of an HMTA material, and second portion 114 consists solely of a high-melting temperature alloy material. High-melting temperature materials (hereinafter "HMTA materials") may include, but are not limited to, Mar-M247, Rene 142, Rene 80, Rene 108, Inconel 738, GT-33, and the like. Second portion 114 may also be referred to as a second HMTA material portion.

[0040] A non-limiting list of possible combinations of HMTA and LMTA materials may include, in order, Mar-M247 and DF4B, Rene 142 and B1P, and Rene 80 and AMS4782. Other combinations are possible. The HMTA material has a higher melting temperature than any other material of the brazing tape 100, and the LMTA material has a lower melting temperature than any other material of the brazing tape 100. Thus, the HMTA material has the highest melting temperature of the brazing tape 100, and the LMTA material has the lowest melting temperature of the brazing tape 100. In one non-limiting example, the LMTA material may have a melting temperature at least 200° C. lower than the HMTA material. The brazing tape 100 is flexible and, therefore, can be curved, bent, rotated, bulged, or otherwise modified to fit virtually any form of irregularly shaped opening and / or contour in the component with which it is used. The brazing tape 100 is not a rigid pre-sintered preform (PSP) since the different parts are not directly bonded to one another, for example with a bonding agent.

[0041] The central portion 116 includes a mixture of LMTA and HMTA materials. That is, the central portion 116 includes both LMTA and HMTA materials. In certain embodiments, as shown in FIG. 2 , the central portion 116 includes the LMTA material at a lower concentration than the HMTA material near the interface 120 (dashed box) between the central portion 116 and the second portion 114. That is, the concentration of the LMTA material is lower in the central portion 116 than the HMTA material near the interface 120. In other embodiments, as shown in FIG. 3 , the central portion 116 includes the LMTA material at a higher concentration than the HMTA material near the interface 122 (dashed box) between the central portion 116 and the first portion 112. That is, the concentration of the LMTA material is higher in the central portion 116 than the HMTA material near the interface 122.

[0042] In another embodiment, as shown in FIG. 4, the ratio of LMTA material to HMTA material varies according to a gradient 130 along the thickness T1 of the central portion 116. The gradient 130 can take any form to tailor the functionality of the brazing tape 100. For example, the gradient 130 can be a substantially linear gradient or a substantially logarithmic gradient. In another example, the gradient 130 can be a positive gradient, for example, with the HMTA material gradually increasing in concentration from the first portion 112 to the second portion 114. Conversely, the gradient 130 can be a positive gradient, for example, with the HMTA material gradually decreasing in concentration from the first portion 112 to the second portion 114. Positive and negative gradients can also be applied to the LMTA material concentration. In another example, as shown in FIG. 5, the gradient 130 can be a step gradient, i.e., each successive individual layer, e.g., 140A-E, has an increasing or decreasing concentration of LMTA material relative to HMTA material, or HMTA material relative to LMTA material. Any number of individual layers 140 can be used, and they can have any thickness. The individual layers 140A-E may or may not have the same thickness.

[0043] Regardless of the configuration, the gradient 130 can be tailored to provide the desired function of the brazing tape 100 through its thickness T1. For example, the LMTA material of the first portion 112, which may contact the area to be repaired on the part 102 (FIGS. 8-9), can be configured to provide the desired adhesion of the brazing tape 100 to an opening or forming surface 104 (FIGS. 8-9) in the part 102 (FIGS. 8-9), which may or may not be smooth. Similarly, the HMTA material of the second portion 114 can be configured to have similar or identical properties to the surface 104 (FIGS. 8-9) of the part 102 (FIGS. 8-9) on which the brazing tape 100 is to be used. The HMTA material of the second portion 114 also prevents adhesion to external tools due to its higher melting temperature.

[0044] As shown in FIG. 6 , in certain embodiments, the brazing tape 100 may also include a higher porosity in the first portion 112 than in the second portion 114, referring to the pores in the first portion 112 being larger compared to the second portion 114. As used herein, “porosity” refers to the ratio of the open space volume to the total volume of a described structure, e.g., its portions 112, 114, 116. Typically, in this regard, porosity is described as the percentage of the open space volume relative to the overall or total volume of the described structure. For example, in certain embodiments, the densest portion, e.g., the second portion 114, has a porosity in the range of 0% to 2.9%, while the least dense portion, e.g., the first portion 112, has a porosity in the range of 3 to 4.9%. As noted above, the densest portion may be considered solid, i.e., 0% porous. In some cases, open space refers to empty regions within a solid material in the form of "pores" (see, e.g., FIG. 6), i.e., small individual open spaces that may contain interconnected passages, e.g., three-dimensional passages, within a material of the described structure. As used herein, the three-dimensional boundaries of a porous portion or sub-portion for purposes of identifying its "total volume" may be identified by where a change in porosity of more than 0.1% occurs relative to adjacent portions or sub-portions. "Open space volume" collectively refers to the three-dimensional space within a portion or sub-portion that is empty, i.e., void, gap, empty space, and / or not filled with material. As used herein, "different porosity" or "porosity difference" generally refers to any of a variety of characteristics, such as the ratio of open space volume to total volume, the number of pores or other open spaces in a given volume, the volume (i.e., size) of the pores or other open spaces, the shape of the pores or open spaces, and variations in connecting passages between pores or other open spaces that may not be recognized as actual separate pores or open spaces. As one non-limiting example only, the pore size may be, for example, 1.715 x 10 -5 ~6.542×10 -2 cubic millimeter (1.000 x 10 -9 ~3.992×10 -6cubic inch). In certain embodiments, the pores may be spherical and have diameters ranging from 0.030 millimeters (mm) to 0.50 mm (0.0012 inches to 0.0197 inches). Other shapes of porosity are possible for gradient porosity configurations, so long as the percentages and variations fall within the stated ranges. It will be recognized that differences in porosity are not necessarily based solely on the ratio of open space volume to total volume, for example, due to differences in pore shape or pore connecting passages. However, when differences in porosity are compared in terms of degree, e.g., higher or lower, the difference referred to is only the difference in volumetric properties, i.e., the ratio of open space volume to total volume.

[0045] In one example, the porosity of the second portion 114 is less than the porosity of the first portion 112, and the porosity of the central portion 116 is less than the porosity of the first portion 112 and more than the porosity of the second portion 114. As shown, the central portion 116 includes a graded porosity, becoming less porous from bottom to top. That is, the porosity is higher near the LMTA material of the first portion 112 and lower near the HMTA material of the second portion 114. The second portion 114 is denser than the central portion 116, and both the second portion 114 and the central portion 116 are denser than the first portion 112.

[0046] 7 shows a schematic cross-sectional view of another embodiment of the brazing tape 100. In this case, the brazing tape 100 further includes a side portion 150 that is continuous with the second portion 114 and includes an HMTA material. The side portion 150 may extend perpendicularly along any extent of the central portion 116 and, if necessary, the first portion 112. In the illustrated example, the side portion 150 extends along an end 152 of the central portion 116 and an end 154 of the first portion 112. Although the side portion 150 is shown at one end of the central portion 116 and the first portion 112, it may also be located at the opposite end of each (see dashed box 156).

[0047] The brazing tape 100 can be made using any now known or later developed tape forming technique, including, but not limited to, controlled sintering such as laser cladding, and fed from two different sources at different speeds to gradually condition the components.

[0048] 8 and 9 show schematic cross-sectional views of a method for repairing a component 102 according to various embodiments of the present disclosure. Referring to FIG. 8 , the method may include placing a brazing tape 100 on a substrate 106 of the component 102. The brazing tape 100 may be any of the embodiments described herein. As shown, at least a first portion 112 is placed in contact with the substrate 106. The substrate 106 of the component 102 may include any portion of the component 102. In the illustrated example, the substrate 106 includes an opening 160 of some form into which the brazing tape 100 fits. In one non-limiting example, the opening 160 may have a depth D greater than 2.5 millimeters (mm) and, although not shown, may have a variety of irregular shapes. Although the brazing tape 100 is shown flush with the surface 104 of the substrate 106 of the component 102, the top surface 162 of the brazing tape 100 may be below the surface 104 of the substrate 106 or may extend above (perpendicular to) the surface 104 of the substrate 106.

[0049] In a non-limiting example, if the component 102 is a turbine nozzle or blade airfoil, or another portion of a turbine along its hot gas path, the component 102 may comprise any of a variety of superalloys. As used herein, “superalloy” refers to an alloy that has numerous superior physical properties compared to conventional alloys, such as, but not limited to, high mechanical strength and high thermal creep deformation resistance. Superalloys may include, but are not limited to, Rene 108, CM247, Haynes alloy, Incalloy, MP98T, TMS alloy, and CMSX single crystal alloy. In one embodiment, superalloys for which the teachings of the present disclosure may be particularly advantageous are those with high gamma prime (γ′) values. “Gamma prime” (γ′) is the primary strengthening phase in nickel-based alloys. Exemplary high gamma prime superalloys include, but are not limited to, Rene 108, N5, GTD 444, MarM 247, and IN 738. The HMTA material of second portion 114 and central portion 116 may be the same as, or at least compatible with, the material of substrate 106 of component 102. "Compatible" indicates that they have similar physical properties and do not chemically interact in a deleterious manner.

[0050] FIG. 8 also illustrates brazing the brazing tape 100 to the substrate 106 (see curved arrow). Brazing may include heating at least the brazing tape 100 to a temperature below the melting temperature of the HMTA material. Brazing may further include heating at least the brazing tape 100 to a temperature above the melting temperature of the HMTA material. Once brazed, any now-known or later-developed finishing process (circular arrow) may be performed to smooth and / or fuse the top surface 162 of the brazing tape 100 and the surface 104 of the component 102. The finishing process may, for example, remove excess material from the brazing tape 100 and / or the surface 104 of the substrate 106 of the component 102 to provide a smooth, continuous surface. The HMTA material of the second portion 114 (and central portion 116) may be the same as, or at least compatible with, the material of the substrate 106 of the component 102. As a result, the repaired component (and particularly where the brazing tape 100 is used) may exhibit the same functionality and benefits as the material of the substrate 106 of the component 102 .

[0051] Figure 9 is the same as Figure 8, but illustrates a method of using the brazing tape 100 of Figure 7 with side portions 150 (and possibly 156). As shown in Figure 9, the brazing tape 100 can be used to repair, among other locations, a corner 164 of the substrate 106 of the component 102.

[0052] Figures 6-9 show the central portion 116 having a slope as in the embodiment of Figure 4. However, it is emphasized that the central portion 116 can take any of the forms described herein.

[0053] The thickness T1 of the central portion 116 constitutes greater than or equal to 90%, i.e., at least 90%, of the total thickness T2 of the brazing tape 100, with the first portion 112 and the second portion 114 constituting the remaining 10% of the total thickness T2. In other embodiments, the thickness T1 of the central portion 116 constitutes greater than or equal to 95%, or at least 95%, of the total thickness T2 of the brazing tape 100, with the first portion 112 and the second portion 114 constituting the remaining 5% of the total thickness.

[0054] Embodiments of the present disclosure offer various technical and commercial advantages, examples of which are discussed herein. The brazing tape is applicable to a wider range of repairs compared to conventional brazing tapes and PSPs, for example, difficult to fill erosion and / or oxidation on the formed sidewalls of internal gas turbine components. The low-melting-temperature alloy material on the first portion that contacts the component ensures adhesion and filling of irregular shapes. Because the central portion contains the high-melting-temperature alloy material, the finishing process reaching through the second portion still leaves the necessary high-melting-temperature alloy material on the surface of the component.

[0055] As used herein throughout the specification and claims, approximation language may be applied to modify any quantitative expression that is subject to variation without resulting in a change in the relevant basic function. Thus, values ​​modified by one or more terms, such as "about," "approximately," and "substantially," are not limited to the exact value specified. In at least some instances, approximation language may correspond to the precision of the instrument used to measure the value. Herein and throughout the specification and claims, range limitations are combinable and / or interchangeable, and unless the context or language dictates otherwise, such ranges are identified and include all subranges encompassed therein. "About" or "approximately," as applied to a particular value in a range, applies to both endpoints and may indicate + / - 10% of the stated value, unless specifically dependent on the precision of the instrument used to measure the value.

[0056] The corresponding structure, material, acts, and equivalents of all means-plus-function or step-plus-function elements in the following claims are intended to include any structure, material, or act for performing the function as specifically claimed in combination with other claimed elements. The description of the present disclosure has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the disclosure to the disclosed form. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The embodiments were chosen and described to best explain the principles of the disclosure and practical applications of the technology, and to enable those skilled in the art to understand the disclosure in order to consider various modifications to the present embodiments that may be suitable for the particular use contemplated. [Explanation of symbols]

[0057] 100 Brazing Tape 102 parts 104 Molding surface, surface 106 Base material 112 First Part 114 Second Part 116 Central part 120 Interface 122 Interface 130 gradient 140A~E Individual layers 150 Side part 152 End 154 End 156 dashed box 160 opening 162 Top surface 164 corner T1 Thickness T2 total thickness D Depth

Claims

1. a first portion (112), a second portion (114), and a central portion (116) located between the first portion (112) and the second portion (114) and adjacent to the first portion (112) and the second portion (114); 1. A brazing tape (100) comprising: said first portion (112) comprising a first alloy material having a first melting temperature; said second portion (114) comprising a second alloy material having a second melting temperature, said second melting temperature being higher than said first melting temperature; and said central portion (116) comprising a mixture of said first alloy material and said second alloy material.

2. The brazing tape (100) of claim 1, wherein the first alloy material is a low melting temperature alloy material and the second alloy material is a high melting temperature alloy material.

3. The brazing tape (100) of claim 1 or 2, wherein the first portion (112) consists solely of the first alloy material.

4. The brazing tape (100) of any one of claims 1 to 3, wherein the second portion (114) consists solely of the second alloy material.

5. 5. The brazing tape (100) of claim 1, wherein the central portion (116) comprises the first alloy material at a lower concentration than the second alloy material near an interface (120) between the central portion (116) and the second portion (114).

6. 6. The brazing tape (100) of any one of claims 1 to 5, wherein the central portion (116) comprises the first alloy material at a higher concentration than the second alloy material near an interface (122) between the central portion (116) and the first portion (112).

7. 7. The brazing tape (100) of claim 1, wherein a ratio of the first alloy material to the second alloy material varies according to a gradient along a thickness (T1) of the central portion (116).

8. The brazing tape (100) of claim 7, wherein the gradient is one of a substantially linear gradient, a substantially logarithmic gradient, a positive or negative gradient, and a step gradient.

9. The brazing tape (100) of any one of claims 1 to 8, wherein the brazing tape (100) has a higher porosity in the first portion (112) than in the second portion (114).

10. 10. The brazing tape (100) of claim 1, wherein the second portion (114) has a lower porosity than the first portion (112), and the central portion (116) has a lower porosity than the first portion (112) and a higher porosity than the second portion (114).

11. 11. The brazing tape (100) of claim 1, further comprising a side portion (150) continuous with the second portion (114) and including the second alloy material, the side portion (150) extending along an end (152) of the central portion (116) and an end (154) of the first portion (112).

12. The brazing tape (100) of any one of claims 1 to 11, wherein the thickness (T1) of the central portion (116) constitutes at least 90% of a total thickness (T2) of the brazing tape (100).

13. The brazing tape (100) of any one of claims 1 to 12, wherein the brazing tape (100) is flexible.

14. A method of repairing a component (102), the method comprising: placing the brazing tape (100) of any one of claims 1 to 13 on a substrate (106) of the component (102), wherein a first portion (112) of the brazing tape (100) is placed in contact with the substrate (106); and brazing the brazing tape (100) to the substrate (106), wherein the brazing comprises heating the brazing tape (100) to a temperature below a melting temperature of a second alloy material. A method comprising:

15. The method of claim 14, wherein the brazing comprises heating the brazing tape (100) to a temperature above a melting temperature of the first alloy material.

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