X-ray scattering method and system for non-destructive inspection of bond lines and porosity

Abstract

Disclosed are methods, systems, and apparatus for nondestructively inspecting bond lines, including those present in composite substrates and in layers of adhesive material within composite substrates, including a small angle X-ray scattering array.

Description

Technical Field

[0001] The present disclosure relates generally to the field of nondestructive testing and nondestructive inspection of subsurface areas of target structures and substrates. More specifically, the present disclosure relates to the field of nondestructive inspection of interlayer properties, such as the bond strength of composite material layers, using small-angle X-ray backscattering techniques. Background Art

[0002] Currently, regulatory guidelines related to the inspection of bonded composite materials in certain industries require the use of testing techniques that destructively test the material. This incurs significant costs because large structures containing composite parts, such as aircraft and other vehicles, must be taken out of service, destructively inspected, and then reworked before the aircraft can be returned to service.

[0003] Nondestructive inspection systems for evaluating substrates have found utility in industry, for example, where various components and substrate materials requiring routine maintenance and inspection may be difficult to access without employing extensive labor or partially or completely destroying the component or substrate material. For a nondestructive testing method or system to replace currently used mandatory destructive methods, the nondestructive testing method must ensure consistent, reliable, and repeatable analysis of the surface or subsurface of the object being inspected that at least equals or exceeds physical determination performed in destructive testing. Summary of the Invention

[0004] Aspects of the present aspects, methods, apparatus, and systems are disclosed that relate to non-destructive inspection of interlayers using small angle X-ray backscatter techniques to accurately confirm the presence or absence of anomalies in the interlayer that, when the interlayer is an adhesive layer, could affect optimal bonding.

[0005] Aspects of the present methods, systems, and apparatuses produce detailed imaging at the nanoscale for use in inspecting composite adhesive interlayers, among other things. When imaging produced according to the presently disclosed techniques does not reveal any anomalies within the composite adhesive interlayer, non-destructive inspection confirms that a satisfactory bond has been established, thereby enabling the inspected area to pass any mandatory bond strength testing protocols that would otherwise result in the destruction of the inspected material.

[0006] According to one aspect of the present invention, a method for non-destructively inspecting bond lines and bond line regions of a composite material is disclosed. The method includes positioning a small-angle X-ray scattering system near the composite material, the composite material comprising a plurality of composite layer stacks, the composite layer stacks comprising a plurality of composite layers. The composite layer stacks include a layer of adhesive material interposed between the composite layer stacks, and the composite material further includes a bond line region disposed within the layer of adhesive material. The small-angle X-ray scattering system includes a plurality of small-angle X-ray scattering system components positioned on a first side of the composite material, the components comprising a monochromatic X-ray tube, a first pinhole and a second pinhole positioned a predetermined distance from the X-ray tube, and a first vacuum chamber positioned near the pinholes and the first side of the composite material. The plurality of small-angle X-ray scattering system components are positioned on a second side of the composite material, the components comprising a second vacuum chamber positioned near the second side of the composite material, the second vacuum chamber being in communication with an X-ray scintillator, and a charge-coupled device camera in communication with the scintillator, the scintillator including a scintillator layer. The presently disclosed method further includes activating the small-angle X-ray scattering system to emit an X-ray beam from the monochromatic X-ray tube; detecting scattered X-rays from the scintillator layer; and generating an imaging signal based on the scattered X-rays that strike the scintillator layer.

[0007] According to other aspects, the presently disclosed method further includes transmitting an imaging signal of scattered X-rays generated on the scintillating layer to a computing device; converting the imaging signal into an image; and displaying a bond line region of the composite assembly as a bond line region image on a small-angle X-ray scattering system output.

[0008] According to another aspect, a disclosed method includes detecting the presence or absence of an anomaly in a bond line region.

[0009] Other aspects disclose non-destructively detecting anomalies in a bond line of a composite material, wherein the anomalies detected in the bond line region may include dimensions from less than 1 nm to about 1.0 mm or greater.

[0010] Other aspects disclose a system for non-destructively inspecting a substrate including a composite material, the system being configured to detect nanoscale anomalies in substrate bond lines, including, for example, substrate bond lines in an epoxy-based composite material substrate, and also including, for example, bond lines in an adhesive layer in a composite substrate. According to aspects of the present invention, the disclosed non-destructive inspection system is configured to non-destructively inspect a substrate, the substrate including a substrate comprising a substrate material having a first substrate material side, a second substrate material side, and at least one interlayer between the first and second substrate material sides. The currently disclosed non-destructive inspection system includes a small-angle X-ray scattering system including microscopic, high-resolution, nanofocus monochromatic X-rays for non-destructively inspecting the substrate. The system further includes a first-side system assembly located on the first side of the substrate material, the first-side system assembly including: a monochromatic X-ray tube; a first pinhole and a second pinhole at a predetermined distance from the X-ray tube; and a first vacuum chamber located between the first pinhole and the second pinhole. The system also includes a second-side system assembly located on the second side of the substrate material, the second-side system assembly including a second vacuum chamber located adjacent the second side of the composite material, the second vacuum chamber being in communication with an X-ray scintillator, a charge-coupled device in communication with the scintillator, and the X-ray scintillator including a scintillating layer. The system further includes imaging software in communication with the charge-coupled device, a display in communication with the imaging software, and the system is configured to inspect a region of the substrate material interlayer.

[0011] According to another aspect, a method for non-destructively inspecting a bond line of an adhesive material layer of a composite material is disclosed. The method includes positioning a small-angle X-ray scattering device proximate to a composite material substrate, wherein the composite material substrate includes an adhesive material layer, and the adhesive material layer includes the bond line. The method also includes directing X-rays from the small-angle X-ray scattering device toward the composite substrate material and detecting scattered X-rays on an X-ray detector, generating an imaging signal of the scattered X-rays detected on the detector, generating an image from the imaging signal, and non-destructively determining the integrity of the bond line.

[0012] In another aspect, the substrate material interlayer region includes a bond line.

[0013] In another aspect, at least a portion of the substrate material comprises a composite material.

[0014] In another aspect, at least a portion of the substrate material comprises a metallic material or a non-metallic material, or a combination thereof.

[0015] In another aspect, the substrate is a primary structure for an aircraft, the primary structure comprising the composite material.

[0016] The features, functions, and advantages that have been discussed can be achieved independently in various aspects or may be combined in yet other aspects, further details of which can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Having described variations of the present disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and in which:

[0018] Figure 1 are diagrams of devices and systems according to the present aspects;

[0019] Figure 2 are diagrams of devices and systems according to the present aspects;

[0020] Figure 3 is a representative illustration of an aircraft including composite structures that may be nondestructively tested according to current aspects;

[0021] Figure 4A is a representative illustration of an aircraft fuselage exterior including a composite structure that may be non-destructively tested according to present aspects;

[0022] Figure 4B is a representative illustration of an aircraft fuselage interior including composite structures that may be non-destructively tested according to present aspects;

[0023] Figure 5 is a representative illustration of a pipeline according to current aspects, the pipeline including a composite structure that can be non-destructively tested;

[0024] Figure 6 is a flowchart outlining a method according to the present aspect;

[0025] Figure 7 is a flowchart outlining a method according to the present aspect;

[0026] Figure 8 is a flowchart outlining the method according to the present aspect; and

[0027] Figure 9 is a flowchart outlining a method according to the present aspect. DETAILED DESCRIPTION

[0028] X-rays are a form of electromagnetic radiation that typically have wavelengths ranging from 0.01 to 10 nanometers, corresponding to frequencies ranging from 30 petahertz to 30 terahertz (3×10 16 Hz to 3×10 19Hz), with an energy range of 100 eV to 100 keV. An X-ray backscatter system is an X-ray imaging system that uses X-rays to examine a target object. An X-ray backscatter system typically includes an X-ray tube, a collimator, and a detector. The X-ray tube generates and emits X-rays. The collimator filters the X-rays to form an X-ray beam, using a portion of the X-rays that propagate substantially parallel to a specified direction.

[0029] When an X-ray beam encounters a target object, some or all of the X-rays in the X-ray beam are scattered in various directions by the target object. In particular, X-rays can be scattered from the surface of the target object, from sub-surfaces of the target object. The scattered X-rays are called backscatter. When the backscatter strikes a detector, the detected backscatter can be used to generate image data of the target object to be investigated. For example, the backscatter detected when the X-ray beam is directed at a specific location on or inside a specific target object can be used to generate an intensity value for a pixel in an image that corresponds to the specific location on or inside the target object. Non-destructive material evaluation using X-rays allows inspection without destroying the part, assembly, substrate, etc. being inspected (e.g., the target object).

[0030] Small angle X-ray scattering (SAXS) is a non-destructive method for investigating nanostructures present in solids and / or liquids. In the SAXS scheme, an X-ray beam strikes a sample of a nanostructure, including, for example, proteins, macromolecules, nanoparticle dispersions, etc. Several imaging techniques have been used to characterize nanostructures by "averaging" the results of a specific sample. Because such methods cannot accurately represent the state of a specific site at the nanoscale level, such methods will be useless in determining the properties of the adhesive layer with confidence. Known non-destructive inspection techniques that only average the features on the substrate area (and cannot provide specific images and inspection results for a specific single point in the area to be investigated) cannot be considered as reliable non-destructive inspection techniques of the type that can replace the required destructive inspection techniques, which are "point-targeted" relative to the specific area or substrate being investigated.

[0031] A typical SAXS system is composed of an X-ray source, a collimator, a sample stage, and a detector in communication with appropriate software, which is used to interpret the X-ray scattering data obtained on the scintillator. The X-ray source emits an X-ray beam that interacts with the electrons of the target sample to determine structural parameters such as particle size, shape, internal structure, porosity, and direction. The scattered X-rays are recorded at different angles, and the scattering pattern at small angles below about 10 ° is analyzed to detect nano-sized particles and domains in the size range of about 1 to about 100 nm (diameter). Before scattering occurs after impacting the sample, the X-rays are converted into a well-defined point beam by collimation. Point collimated beams can be used to analyze anisotropic samples such as fibrous materials or porous solids.

[0032] Aspects of the present invention, methods, apparatus and systems are disclosed that relate to incorporating improved small angle X-ray backscatter systems, arrays and devices that are combined with charge coupled devices to produce two-dimensional nanoscale microscopic images for non-destructive inspection of one or more adhesive interlayers of a composite material, including a bond line, to accurately determine whether anomalies are present in the adhesive interlayer that, if present, would affect optimal bonding of the composite material.

[0033] Aspects of the present methods, systems, and apparatuses generate detailed imaging at the nanoscale level for inspecting composite adhesive interlayers, among other things, to non-destructively inspect bond lines between composite materials and between composite materials bonded to metal, and to non-destructively inspect porosity in adhesive interlayers between composite materials and between composite materials bonded to metal. According to the present aspects, when imaging generated according to the presently disclosed techniques does not reveal anomalies within the adhesive material interlayer, the presently disclosed non-destructive inspection method confirms that a satisfactory bond has been established, thereby allowing the non-destructively inspected area to pass mandatory destructive bond strength testing protocols that would otherwise result in the destruction of the inspected material.

[0034] The small angle X-ray backscatter non-destructive technology made possible by the currently disclosed systems, devices and methods not only allows for a non-destructive confirmatory inspection method for composite adhesive interlayers that may be in a cured state, but also allows for the generation of visual images of composite adhesive interlayers at the nanoscale.

[0035] According to aspects of the present invention, the generation of images (and the capabilities of the present systems, devices, and methods of generating such images) can be visually assessed by an operator or "viewed" and confirmed by automated means (e.g., robots including laser or other reading devices), which enhances the level of ultimate identification and determination of the actual state of the adhesive interlayer. That is, the nanoscale image generation made possible by aspects of the present invention allows and results in the ability to accurately and specifically determine the presence or absence of anomalies in composite adhesive interlayers, which anomalies (if present) may affect the bonding integrity of the composite material (e.g., causing premature delamination of the composite layers, etc.). Compared to currently known destructive inspection techniques required by regulations, aspects of the present invention make it possible to enhance the non-destructive detection and identification of adhesive interlayer anomalies, promoting a safer, more certain inspection technique with higher integrity.

[0036] The enhanced safety, greater certainty, and higher integrity of the present methods, systems, and apparatus are due, at least in part, to the ability to look at more locations along an inspection area of a particular structure and to determine whether a specific number of anomalies exist within those interlayers. This is in contrast to current mandatory destructive inspection techniques, in which a particular structural composite component may pass mandatory tensile strength testing, shear testing, and / or peel strength testing, but the tested area of the composite structure that passed according to currently accepted destructive testing protocols may actually contain a small number of undetected anomalies.

[0037] In stark contrast to accepted and mandated destructive testing protocols, aspects of the presently disclosed systems, apparatus, and methods provide certainty that an inspected area of a composite adhesive interlayer contains any, some, or none of the types of undesirable anomalies in the interlayer that may result in downstream quality conditions requiring rework, but that do not circumvent currently accepted destructive testing protocols. Some of the anomalies that may be present in a composite adhesive interlayer and that can now be detected according to aspects of the presently disclosed apparatus, systems, and methods include nanoscale anomalies such as microvoids, crystallites, stray areas, so-called "kissing debonding," and other very fine areas of material separation.

[0038] Figure 1 The following are schematic diagrams of nondestructive inspection systems and apparatus according to the present invention and are not necessarily drawn to scale. Figure 1 As shown, composite substrate 12 (also equivalently referred to herein as a "composite material substrate") may include a composite substrate first side 11 and a composite substrate second side 13, wherein adhesive material layer 14 includes a bond line 14a (equivalently referred to herein as a "bond line region"), and adhesive material layer 14 is interposed between composite substrate first side 11 and composite substrate second side 13. As further shown, a portion of adhesive material layer 14 including bond line 14a is enlarged to show the enlarged bond line 14a region. Composite substrate first side 11 includes composite substrate first side stack 12a, which includes a plurality of composite substrate first side composite layers 11a. Composite substrate second side 13 includes composite substrate second side stack 12b, which includes a plurality of composite substrate second side composite layers 13a.

[0039] Figure 1Also shown is a small-angle X-ray scattering inspection system 10 for non-destructively inspecting an adhesive material layer (equivalently referred to herein as an "adhesive interlayer") of a substrate and, further, non-destructively inspecting a bond line of the adhesive material layer. The illustrated small-angle X-ray scattering inspection system 10 includes a small-angle X-ray backscattering array having certain small-angle X-ray backscattering components, collectively designated as small-angle X-ray scattering first-side components 16 a, located near (e.g., adjacent to, etc.) or "above" a composite substrate first side 11, and certain small-angle X-ray backscattering components, collectively designated as small-angle X-ray scattering second-side components 16 b, located near (e.g., adjacent to, etc.) or "below" a composite substrate second side 13.

[0040] like Figure 1 As further shown, the small angle X-ray backscattering assembly, collectively represented as the small angle X-ray scattering first side assembly 16a, includes an X-ray source 18, shown as a monochromatic X-ray tube 19 capable of emitting an X-ray beam, a first pinhole 20, a second pinhole 22, and a first vacuum chamber 24. Other small angle X-ray backscattering components, collectively shown as the small angle X-ray scattering second side assembly 16b, include a second vacuum chamber 26, an X-ray scintillator (including an X-ray scintillating layer 28a), and a charge coupled device (CCD) 30 in communication with the scintillator 28. The charge coupled device (CCD) can be a CCD camera that is capable of receiving and / or interpreting signals from the scintillator 28 and can be further configured to generate imaging signals and / or facilitate microscopic imaging. (As shown in FIG. Figure 2 As shown). Figure 1 As shown, the small-angle X-ray backscatter assembly may be supported by a support 32 .

[0041] Figure 2 yes Figure 1 A representative schematic diagram of a system 40 of the general type shown, not necessarily to scale, having a small angle X-ray backscatter component collectively shown as a composite substrate first side component 16a (e.g., Figure 1 shown), in Figure 2 It is collectively shown as the inspection head 41, and has a small angle X-ray backscattering component collectively shown as the composite substrate second side component 16b ( Figure 1 shown), which is Figure 2 The camera head 42 is shown in the middle. Figure 2 It also shows that Figure 1The composite substrate 12 shown includes a composite substrate first side 11 and a composite substrate second side 13, and an adhesive material layer 14, which includes an enlarged portion of the adhesive material 14, showing a bonding line 14a in the adhesive material 14, and the adhesive material layer is located between the composite substrate first side 11 and the composite substrate second side 13.

[0042] like Figure 2 As further shown, the inspection head 41 is connected to the imaging software 43 and the display 44 via a hard connection 41a or via wireless communication. Figure 2 As further shown, camera head 42 is in communication with imaging software 43 and display 44 via a hard connection 42a or via wireless communication. According to another aspect, display 44 can display, in substantially real time, a magnified image 46 of a portion of adhesive material layer 14 of composite substrate 12 being interrogated or otherwise non-destructively inspected by system 40. Imaging signals sent by inspection head 41 and camera head 42 to imaging software 43 are interpreted and converted into an image or images 46, which can be evaluated from display 44, which can be located near system 40, or images 46 can be located and accessed remotely using appropriate hardware, software, and / or networking, including, for example, the Internet, access to cloud storage, etc.

[0043] Figure 3 is a representative illustration of a vehicle in the form of an aircraft 50, which may include components such as a fuselage section 52, which in turn may include Figure 1 and / or Figure 2 Representative and displayed types of composite substrates. Figure 4A Yes Figure 3 An enlarged view of the fuselage section exterior 53 of the fuselage section 52 is shown. Figure 4B Yes Figure 3 and / or Figure 4A An illustration of a fuselage section interior 54 of a fuselage section 52 is shown. Figure 4B Further illustrated by way of non-limiting example is a primary structure, which may be a primary composite structure, mounted as a structural support and assembly for the fuselage section interior 54 , including stringers 56 and frames 59 .

[0044] Figure 5 is an illustration of a fixed object in the form of a composite tube 60 that can be integrated into a pipeline (not shown), wherein the tube 60 includes a composite tube inner portion 62, a composite tube outer portion 64, and a flange 66. Aspects of the present invention contemplate the use of Figure 1 and / or Figure 2 The presently disclosed systems and apparatus are shown to non-destructively inspect at least Figure 3 、 Figure 4A and / or Figure 4BThe adhesive material layer present in the composite material found in the carriers and structures of the types shown and other carrier types and other structures, including Figure 5 A structure (eg, a pipe, line, conduit, pipeline work, etc.) designed for fixed use is shown in a non-limiting manner.

[0045] According to another aspect, the types of composite structures contemplated to benefit from the presently disclosed non-destructive inspection methods, systems, and apparatus include, but are not limited to, manned spacecraft; unmanned spacecraft; manned aircraft; unmanned aircraft; manned hovercraft; unmanned hovercraft, manned rotorcraft; unmanned rotorcraft; manned ground vehicles; unmanned ground vehicles; manned surface vessels; unmanned surface vessels; underwater vessels; unmanned underwater vessels; manned satellites; unmanned satellites; and combinations thereof.

[0046] The present invention relates to combining a point-collimated SAXS system with a charged coupled device (e.g., a CCD camera) and appropriate interpretation software to produce point-by-point nondestructive inspection of adhesive material sandwiches having an average layer thickness ranging from about 0.1 mm to about 5 mm. The adhesive material layer can be an epoxy-based adhesive of the type used to bond epoxy-based composite layers including carbon fiber reinforced plastics (CFRPs) and composite materials incorporating fibers such as carbon / graphite fibers, aramid fibers, boron fibers, glass fibers, and combinations thereof into a resin-based matrix, such as an epoxy-based matrix. Alternatively, the methods, systems, and apparatus of the present invention can nondestructively inspect adhesive layers of non-epoxy-based materials, including, for example, adhesives comprising bismaleimides, cyanate esters, modified acrylates and / or methacrylates, polyurethanes, silicones, and the like.

[0047] On an aircraft, primary structure is defined as any load-bearing structure whose failure could degrade the structural integrity of the aircraft, such as during flight, or could result in injury to passengers or crew, such as during flight. Consequently, a large number of aircraft components are classified as "primary structure" and require periodic inspection and initial certification before entry into service. An illustrative and non-exhaustive list of primary structures on an aircraft includes, for example, seats, fuselage structure, wings, vertical tail, supports and fittings for such listed structures, and most structures that carry flight loads.

[0048] When composite materials are used to manufacture structures, including, for example, primary aircraft structures, such composite materials may include fiber-epoxy-based composite materials comprising fiber matrix layers impregnated with, for example, an epoxy-based material. The impregnated layers are cured and include an adhesive interposed between the layers, and a cured adhesive layer for bonding the composite substrates to each other or to bond the composite structure to a metallic substrate or a non-metallic substrate that does not include the composite material.

[0049] The adhesive used as the adhesive material layer inserted between, for example, the disclosed composite substrates can be any suitable adhesive that can produce sufficient adhesion as determined by mandatory industry specifications and / or regulations. Such adhesives can be curable epoxy-based adhesives, as well as adhesives that can be co-cured with the composite substrate during the manufacturing process of the composite substrate. When the adhesive cures or otherwise "sets," a bond line is formed as a material area in the adhesive material layer. The bond area present on the bond line is an area that must be tested and must physically exceed currently used destructive testing methods, which may include destructive tensile strength testing, destructive peel strength testing, and other mandatory testing schemes. By non-destructively inspecting the actual bond line area of the adhesive layer in actual structures and objects before delivery or during the service life of the object, the currently disclosed methods, systems, and devices improve the overall safety of handling objects by providing more complete physical inspection of a large number of locations, especially difficult-to-access locations, compared to the expensive and time-consuming currently known destructive inspection methods of similar periods.

[0050] Understanding and evaluating the porosity of adhesives or other layers in composite materials is important in determining the predicted and actual load-bearing properties of the adhesive and the components to which it is bonded. Porosity in adhesive materials is evidenced by the occurrence of debonding, interstices due to entrapment of air or other gases, crystallization, etc., and the porosity properties of adhesives contribute to the potential for increased strain and decreased load values.

[0051] By inspecting adhesive material bond lines at the nanoscale level, the presently disclosed methods, systems, and apparatus provide, in real time, actual images of specific point-to-point locations and positions within the bond line region of an adhesive material interlayer during non-destructive inspection, for the purpose of detecting anomalies within the adhesive material and within the bond line at the nanoscale level. The presently disclosed methods thus allow for the ability to discover the presence of nanoscale anomalies in the bond line region of a composite structure that are currently not considered problematic, and therefore currently considered acceptable, due to, for example, the size of the anomaly being below a certain threshold. In other words, currently mandated destructive testing may result in a part or assembly "passing," while the part or assembly may actually include some degree of anomaly that was previously undetectable based on current testing methods.

[0052] Thus, the nanoscale nondestructive inspection methods, systems, and apparatus of the present invention not only produce an enhanced level of inspection compared to known destructive inspection methods, but the methods of the present invention can also provide a level of real-time integrity that can predict the ability of a particular composite material to withstand increased operating stresses than required for a particular component or assembly. That is, once the presently disclosed nondestructive nanoscale testing methods determine the absence of anomalies in the adhesive bond line region, or otherwise determine that the extent of detected anomalies is significantly below a specific acceptable standard, then manufacturing proceeds, and the resulting components and assemblies manufactured according to the manufacturing process (including processes yet to be developed) can potentially achieve verification of enhanced loads, allow for higher performance tolerances, increase field service time, or help achieve other advantages such as further reducing replacement costs, temporary inspection costs, service costs, and the like for various components, assemblies, and structures that incorporate these inspected components and assemblies.

[0053] Figure 6 、 7 and 8 are flowcharts outlining illustrative methods according to the present aspects. Figure 6 A method for non-destructively inspecting a bond line of an adhesive material interlayer of a composite material is disclosed. The method includes positioning a small-angle X-ray scattering system (602) adjacent to the composite material, the composite material comprising a plurality of composite layer stacks, the composite layer stacks comprising a plurality of composite layers. The composite layer stacks comprise an adhesive material interlayer interposed between the composite layer stacks, wherein the adhesive material interlayer further comprises a bond line region. The small-angle X-ray scattering system includes a first-side assembly of the small-angle X-ray scattering system located on a first side of the composite material, the first-side assembly of the small-angle X-ray scattering system comprising: an X-ray source 18, which is shown as a monochromatic X-ray tube; a first pinhole 20 and a second pinhole 22, which are located at a predetermined distance from the X-ray source 18; and a first vacuum chamber 24 located adjacent to the pinholes and the first side of the composite material. Additionally, a second-side assembly of the small-angle X-ray scattering system is located on a second side of the composite material and includes: a second vacuum chamber 26 located adjacent to the second side of the composite material, the second vacuum chamber being in communication with an X-ray scintillator 28; and a charge-coupled device 30 in communication with the scintillator, the scintillator comprising a scintillator layer 28a. Figure 6The method outlined in also includes activating 604 a low-angle X-ray scattering system to emit an X-ray beam from a monochromatic X-ray tube, detecting 606 the scattered X-rays on the scintillating layer; and generating 608 an imaging signal based on the scattered X-rays that strike the scintillating layer. According to the present disclosure, the adhesive may not appear as a "line," but as an "area" in the adhesive material layer. Therefore, the terms "bond line" and bond line area are used equivalently herein with the understanding that the bond line appears within the bond line "area." Therefore, the methods, systems, and apparatus of the present invention non-destructively inspect and otherwise evaluate bond lines and bond line areas of an adhesive material layer in a composite structure including a composite material.

[0054] Figure 7 is a flowchart outlining a method according to the present aspect, wherein method 700 comprises Figure 6 and further comprising sending 702 imaging signals of scattered X-rays generated on the scintillating layer to a computing device, converting 704 the imaging signals into an image; and displaying 706 the bond line region of the composite assembly as a bond line.

[0055] Figure 8 is a flowchart outlining a method according to the present aspect, wherein method 800 comprises Figure 6 and Figure 7 and further comprising detecting 802 an anomaly present in the bond line region.

[0056] Figure 9 is a flow chart outlining a method for non-destructively inspecting a bond line of an adhesive material layer of a composite material, the method 900 comprising positioning 902 a small angle X-ray scattering device proximate to a composite material substrate, wherein the composite material substrate comprises an adhesive material layer, and the adhesive material layer comprises a bond line. The method further comprises directing 904 X-rays from the small angle X-ray scattering device toward the composite substrate material, and detecting 906 the scattered X-rays on an X-ray detector, generating 908 imaging signals of the scattered X-rays detected on the X-ray detector, producing 910 a two-dimensional image from the imaging signals, and non-destructively determining 912 the integrity of the bond line. Figure 1 and Figure 2 The apparatus and system shown in Figure 6 、 7 , 8 and / or 9 and used together with the method outlined in one or more of the foregoing, in order to non-destructively inspect at least Figure 3 、 4A , 4B and or 5, a bond line in an adhesive material interlayer of a composite substrate of the type shown in one or more of.

[0057] Further variations and alternatives of the present disclosure relate to non-destructive inspection of assemblies and components having bond lines, such as composite components of any size, including assemblies and components used to manufacture larger components and structures. Such assemblies and components include, but are not limited to, assemblies and components designed to be incorporated into fixed objects. Such fixed objects include, but are not limited to, bridges, support columns and structures, buildings, general architectural objects, and the like. Other structures and objects include vehicles, such as, but not limited to, aircraft, satellites, rockets, missiles, and the like, and thus also include manned and unmanned aircraft, manned and unmanned spacecraft, manned and unmanned rotorcraft, manned and unmanned ground vehicles, manned and unmanned non-ground vehicles, manned and unmanned surface and underwater vehicles, objects, and structures.

[0058] Furthermore, the present disclosure includes implementations according to the following clauses:

[0059] Clause 1. A method (600) for non-destructively inspecting bond lines in a layer of adhesive material of a composite substrate, the method comprising:

[0060] Positioning (602) a small-angle X-ray scattering system (10) adjacent a composite substrate (12), the composite substrate comprising a layer of adhesive material interposed between a first composite substrate side (11) and a second composite substrate side (13), the layer of adhesive material further comprising a bond line region (14a), wherein the small-angle X-ray scattering system comprises a first-side small-angle X-ray scattering system assembly positioned on the first side of the composite substrate, the first-side small-angle X-ray scattering system assembly comprising:

[0061] X-ray source (18);

[0062] a first pinhole (20) and a second pinhole (22) located at a predetermined distance from the X-ray source (18);

[0063] a first vacuum chamber (24) positioned adjacent the pinhole and the first side of the composite substrate; and

[0064] The small-angle X-ray scattering system includes a small-angle X-ray scattering system second side component located on the second side of the composite substrate, and the small-angle X-ray scattering system component on the second side of the composite substrate includes:

[0065] a second vacuum chamber (26) positioned and attached to the second side of the composite material, the second vacuum chamber being in communication with the X-ray scintillator (28);

[0066] a charge coupled device (30) in communication with an X-ray scintillator, the X-ray scintillator including a scintillator layer (28a);

[0067] activating (604) the small-angle X-ray scattering system to emit an X-ray beam from an X-ray source;

[0068] detecting (606) scattered X-rays on the scintillating layer; and

[0069] An imaging signal is generated (608) based on the scattered X-rays that strike the scintillating layer.

[0070] Clause 2. The method (700) of clause 1, further comprising:

[0071] sending (702) imaging signals of scattered X-rays generated on the scintillating layer to imaging software;

[0072] generating (704) a bond line image (46); and

[0073] The bond line image is displayed (706) on the display (44).

[0074] Clause 3. The method of Clause 2, wherein the bond line image is a two-dimensional image.

[0075] Clause 4. The method (800) of clause 2 or 3, further comprising:

[0076] The bond line is non-destructively inspected (802) for anomalies.

[0077] Clause 5. A method for non-destructively inspecting a bond line of an adhesive material layer of a composite substrate, the method comprising:

[0078] positioning a small angle X-ray scattering device proximate a composite material substrate, the composite substrate comprising a layer of adhesive material, the layer of adhesive material comprising a bond line;

[0079] directing X-rays from a small angle X-ray scattering device toward the composite substrate;

[0080] detecting (606) scattered X-rays on an X-ray scintillator;

[0081] generating (608) an imaging signal of scattered X-rays detected on the X-ray scintillator; and

[0082] generating an image from the imaging signal; and

[0083] Non-destructive inspection of bond lines.

[0084] Clause 6. A system (10) for nondestructively inspecting a composite substrate, the composite substrate comprising a first composite substrate side, a second composite substrate side, and at least one layer of adhesive material, the adhesive material layer being interposed between the first composite substrate side and the second composite substrate side, the system comprising:

[0085] A small-angle X-ray scattering system first side assembly (16a) located on a first side of a composite substrate, the small-angle X-ray scattering system first side assembly comprising:

[0086] Monochromatic X-ray source (18);

[0087] A first pinhole (20) and a second pinhole (22) are located at a predetermined distance from the monochromatic X-ray tube;

[0088] a first vacuum chamber (24) located between the first pinhole and the second pinhole; and

[0089] A small-angle X-ray scattering system second side assembly (16b) located on the second side of the composite substrate, the small-angle X-ray scattering system second side assembly comprising:

[0090] a second vacuum chamber (26) positioned adjacent the second side of the composite material, the second vacuum chamber being in communication with an X-ray scintillator (28); a charge coupled device (30) in communication with the X-ray scintillator (28), the scintillator comprising a scintillator layer (28a);

[0091] Imaging software (43) in communication with the charge coupled device (30);

[0092] a display (44) in communication with the imaging software; and

[0093] The system is configured to display a microscopic two-dimensional image of a layer of adhesive material.

[0094] Clause 7. The system of Clause 6, wherein the composite substrate includes bond lines (14a), and the system is configured to detect nanoscale anomalies in the bond lines.

[0095] Clause 8. The system of clause 6 or 7, wherein the layer of adhesive material comprises bond lines (14a), and the system is configured to detect nanoscale anomalies in the bond lines.

[0096] Clause 9. The system of any of clauses 6-8, wherein the layer of adhesive material includes a bond line region (14a), and the system is configured to detect nanoscale anomalies in the bond line region.

[0097] Clause 10. The system of any of Clauses 6-9, wherein at least a portion of the composite substrate comprises a composite material, and the system is configured to detect nanoscale anomalies in the composite material.

[0098] Clause 11. The system of any of Clauses 6-10, wherein the layer of adhesive material comprises a cured layer of adhesive material, and the system is configured to detect nanoscale anomalies in the cured layer of adhesive material.

[0099] Clause 12. The system of any of Clauses 6-10, wherein the layer of adhesive material comprises an epoxy-based adhesive, and the system is configured to detect nanoscale anomalies in the layer of epoxy-based adhesive material.

[0100] Clause 13. A system according to any of clauses 6-10, wherein the adhesive material layer comprises at least one of: an epoxy-based adhesive; a bismaleimide-based adhesive; a cyanate-based adhesive; an acrylate-based adhesive; a methacrylate-based adhesive; a polyurethane-based adhesive; a silicone-based adhesive; or a combination thereof; and the system is configured to detect nanoscale anomalies in the epoxy-based adhesive material layer.

[0101] Clause 14. The system of any of Clauses 6-13, wherein the system is configured to detect nanoscale anomalies in bond lines of a layer of epoxy-based adhesive material.

[0102] Clause 15. The system of any of Clauses 6-14, wherein the system is configured to detect nanoscale anomalies in bond lines of the epoxy-based composite substrate.

[0103] Clause 16. The system of any of Clauses 6-15, wherein a fixed object (60) comprises the composite substrate, and the system is configured to detect nanoscale anomalies in bond lines of the fixed object.

[0104] Clause 17. A system according to any one of clauses 6-16, wherein the primary structure (52)(56)(57) of the carrier (50) comprises the composite substrate, and the system is configured to detect nanoscale anomalies in bond lines in the primary structure of the carrier.

[0105] Clause 18. The system of any one of Clauses 6-17, wherein the composite substrate comprises a primary structure of an aircraft, and the system is configured to detect nanoscale anomalies in bond lines in the primary structure of the aircraft (50).

[0106] Clause 19. The system of Clause 16, wherein the fixed object is a pipe (60), and the system is configured to detect nanoscale anomalies in bond lines in the pipe.

[0107] Clause 20. The system of clause 17, wherein the carrier is selected from:

[0108] Manned spacecraft; and unmanned spacecraft; manned aircraft; unmanned aircraft; manned hovercraft; unmanned hovercraft; manned rotorcraft; unmanned rotorcraft; manned ground vehicle; unmanned ground vehicle; manned surface vessel; unmanned surface vessel; manned underwater vessel; unmanned underwater vessel; manned satellite; unmanned satellite and combinations thereof, and the system is configured to detect nanoscale anomalies in the bond lines of said vehicles.

[0109] Of course, without departing from the basic characteristics of the present invention, the present invention may be implemented in other ways than those specifically set forth herein. The present embodiment is to be considered in all respects as illustrative and not restrictive, and all changes falling within the meaning and equivalent scope of the appended claims are intended to be included therein.

Claims

1. A method (600) for non-destructively inspecting a bond line in a layer of adhesive material of a composite substrate (12) of a load-bearing structure of a carrier (50) to inspect for anomalies within the adhesive material, the method comprising: Positioning a small-angle X-ray scattering system (10) adjacent a composite substrate (12), the composite substrate comprising a layer of adhesive material interposed between a first composite substrate side (11) and a second composite substrate side (13), the layer of adhesive material further comprising a bond line region (14a), wherein the small-angle X-ray scattering system comprises a first-side small-angle X-ray scattering system assembly positioned on the first composite substrate side, the first-side small-angle X-ray scattering system assembly comprising: X-ray source (18); a first pinhole (20) and a second pinhole (22) located a predetermined distance from the X-ray source (18); a first vacuum chamber (24) positioned adjacent the pinhole and the first side of the composite substrate; and The small-angle X-ray scattering system includes a second-side component of the small-angle X-ray scattering system located on the second side of the composite substrate, and the second-side component of the small-angle X-ray scattering system of the composite substrate includes: a second vacuum chamber (26) positioned adjacent the second side of the composite material, the second vacuum chamber being in communication with an X-ray scintillator (28); a charge coupled device (30) in communication with the X-ray scintillator, the X-ray scintillator comprising a scintillator layer (28a); activating the small-angle X-ray scattering system to emit an X-ray beam from the X-ray source; detecting scattered X-rays on the scintillating layer; generating an imaging signal based on the scattered X-rays striking the scintillating layer; sending imaging signals of scattered X-rays generated on the scintillating layer to imaging software; generating a bond line image (46); and The bond line image is displayed on a display (44). The method of claim 1 , wherein the bond line image is a two-dimensional image.

3. The method according to claim 1 or 2, further comprising: The bond line is non-destructively inspected (802) for anomalies.

4. A system (10) for non-destructively inspecting a composite substrate of a load-bearing structure of a carrier (50), the composite substrate comprising a first composite substrate side, a second composite substrate side, and at least one adhesive material layer interposed between the first composite substrate side and the second composite substrate side, the system comprising: A first side component (16a) of a small-angle X-ray scattering system located on a first side of the composite substrate, the first side component of the small-angle X-ray scattering system comprising: Monochromatic X-ray source (18); A first pinhole (20) and a second pinhole (22) are located at a predetermined distance from the monochromatic X-ray tube; a first vacuum chamber (24) located between the first pinhole and the second pinhole; and A small-angle X-ray scattering second side system component (16b) located on the second side of the composite substrate, the small-angle X-ray scattering second side system component comprising: a second vacuum chamber (26) positioned adjacent the second side of the composite material, the second vacuum chamber being in communication with the X-ray scintillator (28); a charge coupled device (30) in communication with the X-ray scintillator (28), the scintillator comprising a scintillator layer (28a); Imaging software (43) in communication with the charge coupled device (30); a display (44) in communication with the imaging software; and Wherein the system is configured to display a microscopic two-dimensional image of the adhesive material layer by performing the method according to any one of the preceding claims.

5. The system of claim 4, wherein the composite substrate comprises bond lines.

6. The system of claim 4 or 5, wherein the layer of adhesive material comprises a bond line.

7. The system of claim 4 or 5, wherein the layer of adhesive material comprises a bond line region (14a).

8. The system of claim 4 or 5, wherein at least a portion of the composite substrate comprises a composite material.

9. The system of claim 4 or 5, wherein the layer of adhesive material comprises a layer of cured adhesive material.

10. The system of claim 4 or 5, wherein the layer of adhesive material comprises an epoxy-based adhesive.

11. The system of claim 4 or 5, wherein the adhesive material layer comprises at least one of: an epoxy-based adhesive; a bismaleimide-based adhesive; a cyanate-based adhesive; an acrylate-based adhesive; Methacrylate-based adhesives; polyurethane-based adhesives; silicone-based adhesives; or a combination thereof.

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