SYSTEM AND METHOD FOR INSPECTING ADDITIVELY MANUFACTURED COMPONENTS - Patent application

Abstract

To satisfy a need for a cost-effective and efficient non-destructive and non-contact system and method for inspecting an additively manufactured component.SOLUTION: A system and method for inspecting an additively manufactured component include an additive manufacturing head for forming a component layer-by-layer, and an electromagnetic acoustic transducer (EMAT) for inspecting one or more layers of the component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to additive manufacturing processes and components, and more particularly to systems and methods for inspecting additively manufactured components. [Background technology]

[0002] Additive manufacturing systems and methods are used to manufacture components (e.g., parts or products) through multiple layers of material. For example, known additive manufacturing systems and methods manufacture components by adding material layer by layer. Additive manufacturing systems and methods may include or use three-dimensional (3D) modeling (e.g., computer-aided design or CAD) software, computer-controlled additive manufacturing equipment, and powder or liquid feedstock materials.

[0003] Additive manufacturing encompasses a wide variety of techniques and incorporates a variety of technologies, such as laser freeform manufacturing (LFM), laser deposition (LD), direct metal deposition (DMD), laser metal deposition, laser additive manufacturing, laser engineered net shaping (LENS), stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), multi-jet modeling (MJM), 3D printing, rapid prototyping, direct digital manufacturing, layered manufacturing, and additive fabrication. Additionally, a variety of raw materials can be used in additive manufacturing to create products. Examples of such materials include plastics, metals, concrete, and glass.

[0004] One example of an additive manufacturing system is a laser-based additive manufacturing system. Laser additive manufacturing involves spraying or injecting a powder or liquid into a focused beam of a high-powered laser or into the nexus of multiple high-powered lasers under controlled atmospheric conditions, thereby creating a molten pool. The resulting deposit can then be used to build or repair articles for a wide variety of applications. The powder injected into the high-powered laser beam can include a wide variety of materials, such as metals, plastics, etc.

[0005] As the components are formed by additive manufacturing, residual stresses can cause anomalies in the components. Residual stresses can be measured using strain gauges, by drilling holes through the components and / or strain gauges, or by electron beam cutting of lines through or near the components and / or strain gauges. However, drilling holes or electron beam cutting typically destroy the specimen. Furthermore, strain gauges are applied directly to the structure, which often presents problems in terms of practicality and sensitivity. In short, certain known methods of detecting anomalies in components are destructive in that they typically render the monitored components unsuitable for further use and require direct contact, such as by strain gauges.

[0006] As an alternative to measuring surface residual stresses, X-ray diffraction can also be used. However, such systems typically utilize complex and expensive measurement equipment. Moreover, such processes are time consuming. Moreover, to measure subsurface residual stresses, the component is typically chemically milled into multiple layers, thereby destroying the component. Summary of the Invention [Problem to be solved by the invention]

[0007] There is a need for cost-effective, efficient, non-destructive, and non-contact systems and methods for inspecting additively manufactured components. [Means for solving the problem]

[0008] With that need in mind, certain embodiments of the present disclosure provide a system for inspecting an additively manufactured component, the system including an additive manufacturing head configured to form the component layer by layer, and an electromagnetic acoustic transducer (EMAT) configured to inspect one or more layers of the component.

[0009] In at least one embodiment, the system includes a vessel defining a chamber. The additive manufacturing head is configured to form a component within the vessel. In at least one embodiment, one or both of the additive manufacturing head or the EMAT are within the chamber. In at least one embodiment, one or both of the additive manufacturing head or the EMAT are moveable relative to the chamber.

[0010] In at least one example, the EMAT is configured to inspect one or more layers of the component as the component is being formed by the additive manufacturing head. In at least one other example, the EMAT is configured to inspect one or more layers of the component after the one or more layers are formed by the additive manufacturing head.

[0011] In at least one embodiment, the EMAT does not contact one or more layers of the component.

[0012] In at least one embodiment, the system also includes an inspection control unit in communication with the EMAT. The inspection control unit is configured to analyze the inspection data for the one or more layers to determine the presence of one or more anomalies within or between the one or more layers. The inspection data is generated by the EMAT. The inspection control unit is configured to output an alert to a user interface in response to detecting the presence of the one or more anomalies. For example, the alert may include one or both of an image or a description of the one or more anomalies.

[0013] The EMAT can be coupled to an additive manufacturing head. The EMAT can be decoupled from the additive manufacturing head. The additive manufacturing head can be movably coupled to a first support member and the EMAT can be movably coupled to a second support member.

[0014] Certain embodiments of the present disclosure provide a method for inspecting an additively manufactured component, the method including forming the component layer-by-layer with an additive manufacturing head and inspecting one or more layers of the component with an electromagnetic acoustic transducer (EMAT).

[0015] In at least one embodiment, the forming step includes forming a component within a chamber of a container.

[0016] The method may include positioning one or both of an additive manufacturing head or an EMAT in the chamber and / or moving one or both of the additive manufacturing head or the EMAT relative to the chamber.

[0017] In at least one embodiment, the method further includes generating (by the EMAT) inspection data for one or more layers, analyzing (by a test control unit in communication with the EMAT) the inspection data for the one or more layers, and determining through said analyzing a presence of one or more anomalies within or between the one or more layers. The method may also include outputting (by the test control unit) an alert to a user interface in response to detecting the presence of the one or more anomalies. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram of an inspection system for additively manufactured components according to one embodiment of the present disclosure. [Diagram 2] FIG. 1 is a schematic diagram of an electromagnetic acoustic transducer (EMAT) coupled to an additive manufacturing head according to one embodiment of the present disclosure. [Diagram 3]FIG. 1 is a schematic diagram of an EMAT and an additive manufacturing head according to one embodiment of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of an inspection system for additively manufactured components according to one embodiment of the present disclosure. [Diagram 5] FIG. 1 is a schematic diagram of an inspection system for additively manufactured components according to one embodiment of the present disclosure. [Figure 6] 1 is a flowchart of a method for inspecting an additively manufactured component according to one embodiment of the present disclosure. [Figure 7] FIG. 1 is a block diagram of a testing environment according to one embodiment of the present disclosure. [Figure 8] FIG. 1 is a block diagram of an electromagnetic acoustic transducer according to one embodiment of the present disclosure. [Figure 9] FIG. 1 is a block diagram of a magnetic field generating environment according to one embodiment of the present disclosure. [Figure 10] FIG. 1 is a cross-sectional view of an electromagnetic acoustic transducer according to one embodiment of the present disclosure. [Figure 11] FIG. 1 illustrates an implementation of a magnetic field and a production environment according to one embodiment of the present disclosure. [Figure 12] FIG. 2 illustrates an antenna according to one embodiment of the present disclosure. [Figure 13] FIG. 1 illustrates an electric field aligned with a test object according to an embodiment of the present disclosure. [Figure 14] 1 is an illustration of an aircraft in which an advantageous embodiment may be implemented; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The foregoing summary, as well as the following detailed description of certain embodiments, will be better understood when read in conjunction with the accompanying drawings. As used herein, it should be understood that the use of "a" or "an" preceding an element or step in the singular does not exclude a plurality of elements or steps. Furthermore, references to "one embodiment" are not to be interpreted as excluding the existence of additional embodiments that incorporate the recited features. Furthermore, unless expressly stated otherwise, an embodiment "comprising" or "having" one or more elements having a particular condition may also include additional elements that do not have that condition.

[0020] Certain embodiments of the present disclosure provide an inspection system for additively manufactured components that includes a superconducting electromagnetic acoustic transducer used to measure residual stresses in the components. The system and method can be utilized during manufacturing as well as during maintenance and servicing. Residual stress measurements are used to evaluate compressive residual stresses imparted to aerospace hardware using processes such as shot peening, laser shock peening, water cavitation peening, etc.

[0021] In at least one embodiment, an electromagnetic acoustic transducer (EMAT), such as a superconducting EMAT, scans over the surface of a layer of an additively manufactured component, thereby creating an image of the residual stress of the layer or set of layers that is used to evaluate the quality of the layer. As such, the EMAT is used to monitor the manufacturing and / or repair process of the component. In at least one embodiment, the EMAT is attached to an end effector of an additive manufacturing device, such as an additive manufacturing head, such that the EMAT tracks the end effector during the forming process and collects high sensitivity acoustic signals, which can create an image of the signal (amplitude, time of flight, frequency response). The acoustic signal received by the EMAT varies based on the residual stress of the additive material created during the additive manufacturing process. The resulting image of the most recently applied layer is analyzed for out-of-tolerance conditions, particularly residual stresses, as well as cracks and fusion or knit line defects. In at least one embodiment, the inspection data acquired by the EMAT can also be automatically compared to data from an identical set of layers from a reference part or a digital dataset representing that part.

[0022] An embodiment of the present disclosure provides a system and method for inspecting additively manufactured components using a superconducting electromagnetic acoustic transducer (SC EMAT). In at least one embodiment, a method for non-destructive inspection of additively manufactured components includes coupling a superconducting electromagnetic acoustic transducer (SC EMAT) to an additive manufacturing head, scanning each additional layer of material using an electromagnetic acoustic signal, creating an image of the residual stress of the laid down layer, representing the amplitude, time of flight, and frequency of the reflected acoustic signal, comparing the image to a reference image, analyzing the image, detecting anomalies outside of the tolerance range, deciding to continue the AM manufacturing process, repeating or repairing the laid down layer, and storing the collected images for future reference during the operational life of the additively manufactured component.

[0023] Certain embodiments of the present disclosure provide a system for inspecting an additively manufactured component, the system including an additive manufacturing head configured to form the component layer by layer, and an electromagnetic acoustic transducer (EMAT) configured to inspect one or more layers of the component.

[0024] Certain embodiments of the present disclosure provide a method for inspecting an additively manufactured component, the method including forming the component layer-by-layer with an additively manufactured head and inspecting one or more layers of the component with an EMAT.

[0025] 1 illustrates a schematic diagram of an inspection system 100 for an additively manufactured component 102, according to one embodiment of the present disclosure. The inspection system 100 includes a container 104 including a base 106 and a wall 108 upstanding from the base 106. The base 106 and the wall 108 define a chamber 110.

[0026] The additive manufacturing head 112 is fixed in position or movable relative to the chamber 110. The additive manufacturing head 112 includes an emitter 114. In at least one embodiment, the emitter 114 outputs an ink or other such medium. For example, the additive manufacturing head 112 can be part of a 3D printer that forms the component 102. As another example, the emitter 114 outputs energy (such as laser energy) to a powder bed to form the component. The additive manufacturing head 112 is part of an additive manufacturing forming system configured to form the component 102 layer by layer via laser freeform manufacturing (LFM), laser deposition (LD), direct metal deposition (DMD), laser metal deposition, laser additive manufacturing, laser engineered net shaping (LENS), stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), multi-jet modeling (MJM), 3D printing, rapid prototyping, direct digital manufacturing, layered manufacturing, additive fabrication, and the like.

[0027] The additive manufacturing head 112 forms the component 102 layer by layer, such as from a base surface 116 toward a top surface 118, in a build direction 120. As shown, the build direction 120 may be a vertical direction extending upward from the base 106 in the chamber 110. In at least one embodiment, the additive manufacturing head 112 is a laser scanner that emits energy as one or more laser beams via an emitter 114, which may be a laser output, an array, or the like. Optionally, the additive manufacturing head 112 may be an electron beam scanner that emits one or more electron beams via an emitter 114, which may be an electron beam output, an array, or the like. As another example, the additive manufacturing head 112 may be an arc scanner that emits electric arc energy via an emitter 114, which may be an arc output, an array, or the like. As another example, the additive manufacturing head 112 may be or be part of a 3D printer. U.S. Patent No. 9,751,260, entitled "Additive Manufacturing Systems, Apparatuses, and Methods," discloses an example of an additive manufacturing head.

[0028] In at least one embodiment, the additive manufacturing head 112 communicates with a forming control unit 122, such as via one or more wired or wireless connections. The forming control unit 122 is configured to control (e.g., operate) the additive manufacturing head 112 to form the component 102. The forming control unit 122 may be configured to operate the additive manufacturing head 112 via pre-programmed instructions stored in a memory.

[0029] An electromagnetic acoustic transducer (EMAT) 124 is configured to inspect the component 102 during or after the manufacturing process. In at least one embodiment, the EMAT 124 is within the chamber 110. For example, the EMAT 124 is fixed and / or movably fixed within the chamber 110. The EMAT 124 outputs an acoustic signal 125 to the component 102. The EMAT 124 receives a reflected acoustic signal 127 from the component 102. The acoustic signal received by the EMAT 124 (i.e., the reflected acoustic signal 127) varies based on the residual stress of a material within the component 102, such as the residual stress of an additive material created during an additive manufacturing process. The reflected acoustic signal 127 received by the EMAT 124 generates inspection data for the component 102.

[0030] The EMAT 124 emits an acoustic signal 125 and receives a reflected acoustic signal 127 without contacting the component 102. Thus, the EMAT 124 inspects the component 102 in a non-contact, non-destructive manner. An example of an EMAT 124 is described in U.S. Patent No. 8,806,950, entitled "Electromagnetic Acoustic Transducer System."

[0031] The EMAT 124 is in communication with a test control unit 126, which controls the operation of the EMAT 124 and analyzes test data received from the EMAT 124, such as data indicative of reflected acoustic signal 127. The EMAT 124 is communicatively coupled to the test control unit 126, such as via one or more wired or wireless connections. The test control unit 126 may be configured to operate the EMAT 124 via pre-programmed instructions stored in a memory.

[0032] In at least one embodiment, the test control unit 126 is also in communication with a user interface 130, such as via one or more wired or wireless connections. The user interface 130 includes a display 132, such as a monitor, screen, or the like. In at least one embodiment, the user interface 130 is a computer workstation. In at least one embodiment, the user interface 130 is a handheld device, such as a smartphone or tablet.

[0033] In at least one embodiment, the inspection control unit 126 is configured to display an image of the component 102 on the display 132. The image may be formed through analysis of the inspection data received from the EMAT 124.

[0034] During operation, the additive manufacturing head 112 forms layers 128 of the component 102, thereby forming the component 102 layer-by-layer in the build direction 120, from the base surface 116 to the top surface 118. For example, the additive manufacturing head 112 selectively laser sinters layer 128 onto an existing layer 128 previously formed from material in a powder bed.

[0035] During or after the formation process, the EMAT 124 emits an acoustic signal 125 to the component 102, for example to each layer 128, as (and / or after) each layer 128 is formed. The EMAT 124 receives a reflected acoustic signal 127 from the component 102. The inspection control unit 126 analyzes the reflected acoustic signal 127 to determine anomalies (cracks, stress, voids, etc.) in the layer 128. The inspection control unit 126 analyzes inspection data including information about the reflected acoustic signal to determine the location of the anomalies in the layer 128 of the component 102. In at least one embodiment, the inspection control unit 126 forms an image of the layer 128 of the component 102 based on the inspection data. The image may be displayed on a display 132 of the user interface 130.

[0036] In at least one embodiment, the EMAT 124 is configured to inspect the component 102 (such as by emitting an acoustic signal 125 and receiving a reflected acoustic signal 127) as the component 102 is being formed layer by layer. Alternatively, the EMAT 124 can inspect the component 102 after it is fully formed.

[0037] The EMAT 124 can inspect the component 102 from the side. As another example, the EMAT 124 can be positioned above or below the component 102. The EMAT 124 inspects the component 102, thereby enabling the inspection control unit 126 to form an image of the residual stress in each layer 128 or set of layers 128 as or after the layers 128 are formed.

[0038] In at least one embodiment, the EMAT 124 is attached to the additive manufacturing head 112 such that the EMAT 124 tracks the additive manufacturing head 112 as a layer 128 of the component 102 is formed. The EMAT 124 receives reflected acoustic signals 127 from the layer 128, thereby enabling the inspection control unit 126 to create an image related to the received reflected acoustic signals 127 (indicative of amplitude, time of flight, frequency response, etc.). The reflected acoustic signals 127 received by the EMAT 124 vary based on the residual stresses of the added material created during the additive manufacturing process.

[0039] The resulting images of the most recently applied layer 128 are analyzed by the inspection control unit 126 for out-of-tolerance conditions, particularly residual stresses, and anomalies such as cracks, fusions, or knit line defects. In at least one embodiment, the inspection data acquired by the EMAT 124 may also be automatically compared to data from an identical set of layers from a reference part or a digital dataset representing the part. If acceptable data is received, the component 102 formation process continues until the component 102 is complete. However, if out-of-tolerance data is found in a layer 128 of the component 102, the inspection control unit 126 outputs an alert to the user interface 130. In at least one embodiment, a model of the layer 128 with an anomaly is automatically run to predict the effect of the anomaly on performance and / or an operator can stop the process, evaluate the defect, and make a decision regarding repair.

[0040] As used herein, terms such as "control unit," "central processing unit," "unit," "CPU," "computer," and the like, may include any processor-based or microprocessor-based system, including systems using microcontrollers, reduced instruction set computers (RISC), application specific integrated circuits (ASIC), logic circuits, and any other circuits or processors, including hardware, software, or combinations thereof, capable of performing the functions described herein. These are merely examples and are not intended to limit in any way the definition and / or meaning of such terms. For example, the formation control unit 122 and the inspection control unit 126 may be or include one or more processors configured to control their operation as described herein.

[0041] The formation control unit 122 and the inspection control unit 126 are configured to execute a set of instructions stored in one or more data storage units or elements (e.g., one or more memories) to process data. For example, the formation control unit 122 and the inspection control unit 126 can include or be coupled to one or more memories. The data storage units can also store data or other information, as desired. The data storage units may be in the form of an information source or a physical memory element within a processing machine. The one or more data storage units or elements can comprise volatile or non-volatile memory, or can include both volatile and non-volatile memory. By way of example, the non-volatile memory can include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable PROM (EEPROM), and / or flash memory, and the volatile memory can include random access memory (RAM), which can function as an external cache memory. The data store of the disclosed systems and methods is intended to include, without being limited to, these and any other suitable types of memory.

[0042] The set of instructions may include various commands that instruct the forming control unit 122 and the inspection control unit 126 as a processing machine to perform certain operations, such as the methods and processes of various embodiments of the subject matter described herein. The set of instructions may be in the form of a software program. The software may be in various forms, such as system software or application software. Furthermore, the software may be in the form of a collection of separate programs, a program subset within a larger program, or a portion of a program. The software may include modular programming in the form of object-oriented programming. The processing of input data by the processing machine may be in response to user commands, or depending on results of previous processing, or in response to a request made by another processing machine.

[0043] The diagrams of the embodiments herein may show one or more control or processing units, such as the formation control unit 122 and the inspection control unit 126. It should be understood that the processing or control unit may represent a circuit, circuitry, or a portion thereof, that may be implemented as hardware with associated instructions (e.g., software stored in a tangible non-transitory computer-readable storage medium, such as a computer hard drive, ROM, RAM, etc.) to perform the operations described herein. The hardware may include state machine circuitry hardwired to perform the functions described herein. Optionally, the hardware may include electronic circuitry including and / or connected to one or more logic-based devices, such as a microprocessor, processor, controller, etc. Optionally, the formation control unit 122 and the inspection control unit 126 may represent one or more processing circuitry, such as a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a microprocessor, etc. The circuitry in various embodiments may be configured to execute one or more algorithms to perform the functions described herein. One or more algorithms may include aspects of the embodiments disclosed herein, whether or not explicitly identified in a flowchart or method.

[0044] As used herein, the terms "software" and "firmware" are used interchangeably and include any computer program stored in a data storage unit (e.g., one or more memories) for execution by a computer, including RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory. The above types of data storage units are merely exemplary and thus are not limiting on the types of memory that may be used to store a computer program.

[0045] 2 illustrates a schematic diagram of an EMAT 124 coupled to an additive manufacturing head 112, according to one embodiment of the disclosure. As shown, in at least one embodiment, the EMAT 124 is directly coupled to the additive manufacturing head 112. For example, the EMAT 124 can be secured to the additive manufacturing head 112 via fasteners, adhesives, or the like. As another example, the EMAT 124 can be integrally formed with the additive manufacturing head 112. As another example, the EMAT 124 can be coupled to the additive manufacturing head 112 and positioned remotely from the additive manufacturing head 112 by one or more of a coupling link, e.g., a beam, a bracket, a housing, or the like.

[0046] In at least one embodiment, EMAT 124 follows additive manufacturing head 112 in a direction of movement 140. Thus, additive manufacturing head 112 forms layers 128 of component 102 (shown in FIG. 1 ) in the direction of movement, and EMAT 124 inspects layers 128 after they are formed, while the additive manufacturing head continues to form portions of layers 128. In this manner, EMAT 124 can inspect layers 128 as they are formed or after they are formed.

[0047] In at least one embodiment, the additive manufacturing head 112 is coupled to an actuator 142, such as a motor coupled to one or more wheels, conveyors, gears, pulleys, etc. The actuator 142 may be operably coupled to a track 144, which may be fixed within, above, and / or below the chamber 110 of the vessel 104. The actuator 142 is configured to move the additive manufacturing head 112, and thus the EMAT 124, relative to the vessel 104 (shown in FIG. 1 ). Alternatively, one or both of the additive manufacturing head 112 and / or EMAT 124 are fixed in position relative to the vessel 104.

[0048] 3 shows a schematic diagram of the EMAT 124 and the additive manufacturing head 112, according to one embodiment of the disclosure. In this embodiment, the EMAT 124 and the additive manufacturing head 112 are separate and distinct from one another. For example, the EMAT 124 can be coupled to a first actuator 146 that movably couples the EMAT 124 to a first track 148, and the additive manufacturing head 112 can be coupled to a second actuator 150 that movably couples the additive manufacturing head 112 to a second track 152. Alternatively, one or both of the additive manufacturing head 112 and / or the EMAT 124 can be fixed in place.

[0049] 4 illustrates a schematic diagram of an inspection system 100 for an additively manufactured component 102, according to one embodiment of the present disclosure. As shown, the additive manufacturing head 112 is coupled to a first support member 160, such as one or more brackets, beams, tracks, etc., and the EMAT 124 is coupled to a second support member 162, such as one or more brackets, beams, tracks, etc. Both the additive manufacturing head 112 and the EMAT 124 are above the component 102. The component 102 is built layer-by-layer in a bottom-up manner from the base to the top by the additive manufacturing head 112. Optionally, one or both of the additive manufacturing head 112 and / or the EMAT 124 can be located below or on the side of the component 102.

[0050] In at least one embodiment, the additive manufacturing head 112 can form a layer 128 of the component 102 and then move away from the component 102. The EMAT 124 can then be moved over the component 102 to inspect the layer 128. After the EMAT 124 has inspected the layer 128, the EMAT 124 moves away from the component 102 and the additive manufacturing head 112 moves over the layer 128 to form another layer 128 on top of the layer 128 below. The process is then repeated.

[0051] 5 illustrates a schematic diagram of an inspection system 100 for an additively manufactured component 102, according to one embodiment of the present disclosure. As shown, in at least one embodiment, an EMAT 124 can follow the additive manufacturing head 112 and inspect the layers 128 as they are formed.

[0052] 6 illustrates a flow chart of a method for inspecting an additively manufactured component, according to one embodiment of the disclosure. With reference to FIGS. 1 and 6, at 170, the additive manufacturing head 112 forms one or more layers 128 of the component 102. At 172, the EMAT 124 inspects the layer 128. For example, the EMAT 124 emits an acoustic signal 125 to the layer 128 and receives a reflected acoustic signal 127 from the layer 128, thereby generating inspection data for the layer 128. In at least one embodiment, the EMAT 124 inspects each layer 128 as or after the layer 128 is formed.

[0053] At 174, test control unit 126 analyzes the test data generated by EMAT 124 to determine whether there are any anomalies in layer 128. For example, test control unit 126 compares the test data to control or reference data for layers without anomalies. If test control unit 126 determines at 174 that there are no anomalies, the method returns to 170, where a subsequent layer 128 (or layers) is formed. However, if test control unit 126 determines at 174 that there are anomalies, the method proceeds from 174 to 176, where test control unit 126 outputs an alert to user interface 130. The alert may include an image and / or a description of the anomaly.

[0054] 7 illustrates a block diagram of a testing environment, according to one embodiment of the present disclosure. Certain embodiments recognize and take into account that most magnets currently used in electromagnetic acoustic transducers may not provide a strong enough magnetic field to generate sound waves in materials that have low connectivity compared to metals and alloys. For example, certain embodiments recognize and take into account that currently used electromagnetic acoustic transducers may have difficulty generating desired sound waves in components such as composite structures.

[0055] Certain embodiments recognize and take into account that the desired acoustic waves may be generated when the magnetic field is increased to a sufficiently high level. Accordingly, certain embodiments provide a method and apparatus for generating acoustic waves in a layer of a component. In at least one embodiment, the apparatus includes a conductive material and a current inducer. The conductive material is configured to generate a magnetic field. The magnetic field has substantially fixed magnetic flux lines. Further, the current inducer is configured to generate a current in the layer that interacts with the magnetic field. The frequency of the current generates an acoustic test wave in the layer of the component.

[0056] 7, a block diagram of a testing environment is shown. In this example, the testing environment 1100 includes a non-destructive testing (NDI) system 1102 that provides an example of the EMAT 124 and the inspection control unit 126 (shown in FIG. 1). As shown, the non-destructive testing (NDI) system 1102 can be used to perform tests on a test object 1104 (which is an example of the component 102 shown in FIG. 1). The test object 1104 can take a number of different forms. For example, the test object 1104 can be selected from one of a skin panel, a composite skin panel, a metal skin panel, a fuselage, a wing, an engine housing, a composite structure, an aircraft, a spacecraft, a submarine, a mold, and / or other suitable object.

[0057] For example, the non-destructive inspection system 1102 can be used to determine whether an inconsistency 1106 (eg, anomaly) is present in the test object 1104 .

[0058] In this illustrative example, the non-destructive inspection system 1102 takes the form of an ultrasonic inspection system 1108. The ultrasonic inspection system 1108 can be used to generate and detect acoustic waves 1110 in the test object 1104. In these illustrative examples, the ultrasonic inspection system 1108 includes a processing element 1112 and a transducer system 1114. The processing element 1112 is configured to cause the transducer system 1114 to generate the acoustic waves 1110 in the test object 1104. In addition, the processing element 1112 is also configured to cause the transducer system 1114 to detect responses 1116 generated from the acoustic waves 1110.

[0059] In this example, the processing element 1112 includes a controller 1118, a data collector 1120, and an analyzer 1122. The controller 1118, the data collector 1120, and the analyzer 1122 may be implemented using hardware, software, or a combination of the two. As shown, the components of the processing element 1112 may be implemented using a computer system 1124. The computer system 1124 is one or more computers. When multiple computers are present, the computers may be in communication with each other via a medium such as a network.

[0060] The data collector 1120 is configured to record and store data 1126 of at least one of the generated acoustic waves 1110 and the detected responses 1116 in response to the acoustic waves 1110 .

[0061] As used herein, the phrase "at least one" when used in conjunction with a list of items means that different combinations of one or more of the listed items may be used and only one of each item in the list may be required. For example, "at least one of item A, item B, and item C" may include, for example, but is not limited to, item A, or item A and item B. This example may also include item A, item B, and item C, or item B and item C. This data may include, for example, but is not limited to, the amplitude of the sound wave 1110, the amplitude of the response 1116, the time the sound wave 1110 was transmitted and the time the response 1116 was received, as well as other suitable types of data.

[0062] The analyzer 1122 may be configured to analyze the data 1126 to determine whether the inconsistency 1106 exists. Additionally, the analyzer 1122 may display the data 1126 on a display device 1128 of the computer system 1124.

[0063] As shown, the transducer system 1114 is implemented using hardware and includes a positioning system 1130 and a number of transducers 1132. The positioning system 1130 may be a fixed system or a mobile system. If the positioning system 1130 is a mobile system, the positioning system 1130 may be a robot or other suitable automated system under the control of the controller 1118. In these examples, the number of transducers 1132 take the form of an electromagnetic acoustic transducer 1134. The electromagnetic acoustic transducer 1134 is an example of the EMAT 124 shown in FIG. 1 .

[0064] Turning now to Figure 8, a block diagram of an electromagnetic acoustic transducer is shown in accordance with an advantageous embodiment. In this example, electromagnetic acoustic transducer 200 is an example of EMAT 124 as shown in Figure 1 and EMAT 1134 as shown in Figure 7.

[0065] In these illustrative examples, electromagnetic acoustic transducer 200 may include a housing 202, a conductive material 204, a current inducer 206, a vacuum system 208, and a cooling system 210. In these illustrative examples, conductive material 204, current inducer 206, vacuum system 208, and cooling system 210 are associated with housing 202.

[0066] Where one component is "associated" with another component, in these illustrative examples, the association is a physical association. For example, a first component may be considered to be associated with a second component by being fixed to the second component, bonded to the second component, attached to the second component, welded to the second component, fastened to the second component, and / or connected to the second component in any other suitable manner. A first component may also be connected to a second component using a third component. A first component may also be considered to be associated with a second component by being formed as part of and / or as an extension of the second component.

[0067] In this example, the conductive material 204 is a magnetic field source and is configured to generate a magnetic field 212. The current inducer 206 is configured to generate radiation 214 at a frequency 215. In this example, the radiation 214 causes a current 216 to flow in the test object 218. In particular, the current 216 may take the form of an eddy current 220.

[0068] When the current 216 interacts with the magnetic field 212, an acoustic wave 222 is generated. As shown, the frequency 228 is derived from the frequency 215 of the radiation 214 in these examples. In other words, the frequency 228 is determined by the frequency 215. In these examples, the frequency 228 is the same as the frequency 215. This change generates an acoustic wave 222 at a frequency 226. In these examples, the controller 1118 of FIG. 7 is configured to cause the current inducer 206 to generate the current 216 at frequency 228, causing the acoustic wave 222 to have a frequency 226, which is the desired frequency in these examples.

[0069] In these illustrative examples, acoustic waves 222 take the form of ultrasound waves 230. A frequency 226 of acoustic waves 222 is selected by selecting a frequency 228 for radiation 214. Frequency 226 of acoustic waves 222 can be, for example, from about 20 kilohertz (kHz) to about 20 megahertz (MHz). It should be understood that the frequency used can depend on the particular implementation.

[0070] The conductive material 204 is configured to generate a magnetic field 212 having substantially fixed magnetic flux lines 224. When the magnetic flux lines 224 are substantially fixed relative to the conductive material 204, the conductive material 204 is a trapped magnetic field conductive material. The magnetic flux lines 224 are substantially fixed relative to the electromagnetic acoustic transducer 200. A permanent magnet includes magnetic domains that are oriented in the same direction when exposed to an external magnetic field. In contrast, a trapped magnetic field conductive material does not have any magnetized portions until the trapped magnetic field conductive material is exposed to an external field. After being exposed to an external magnetic field, the trapped magnetic field conductive material becomes magnetized and can maintain some of its magnetization after the external field is removed.

[0071] The conductive material 204 is selected as a material that has substantially zero electrical resistance at a selected temperature or temperature range. In these examples, the conductive material 204 takes the form of a superconductor 232. When the temperature 234 of the superconductor 232 is reduced below an operating temperature 235, the superconductor 232 is configured to have substantially zero electrical resistance. In these examples, the conductive material 204 may be selected from one of bismuth strontium calcium copper oxide, yttrium barium copper oxide (YBCO), magnesium diboride, lanthanum barium copper oxide, bisethylenedithiotetrathiafulvalene, and other suitable materials. In examples, the yttrium in the yttrium barium copper oxide may be replaced with materials such as, for example, gadolinium, dysprosium, neodymium, samarium, europium, and other rare earth materials. For example, gadolinium barium copper oxide, dysprosium barium copper oxide, neodymium barium copper oxide, samarium barium copper oxide, and europium barium copper oxide may be used. Use of these materials may also allow the conductive material 204 to generate the desired trapped flux.

[0072] The critical temperature of superconductor 232 is the temperature below which the electrical resistance becomes zero. The operating temperature 235 of superconductor 232 is below the critical temperature in these embodiments.

[0073] The superconductor 232 may be selected as a high temperature superconductor 236. The high temperature superconductor 236 is composed of an electrically conductive material that has substantially zero resistance at temperatures above about 30 degrees Kelvin (K).

[0074] In these illustrative examples, vacuum system 208 and cooling system 210 are configured for use in maintaining temperature 234 of conductive material 204 at a level where substantially zero resistance exists and where magnetic flux lines 224 within magnetic field 212 are substantially fixed. In these illustrative examples, vacuum system 208 is configured to create a vacuum around conductive material 204. This vacuum, in conjunction with cooling system 210, can maintain temperature 234 of conductive material 204 at a desired temperature.

[0075] By being substantially fixed, the magnetic flux lines 224 remain in substantially the same location when the conductive material 204 does not move. In these examples, the current inducer 206 comprises at least one of a coil 237 and an antenna system 238. The coil 237 is configured to generate a magnetic field 239 at a frequency 241 such that a current 216 flows in the test object 218 at a frequency 228. The coil 237 may be any coil capable of generating a magnetic field 239 to induce a flow of the current 216 in the test object 218.

[0076] As shown, antenna system 238 includes multiple antennas 240. As used herein, "number," when used with respect to an item, means one or more of the item. For example, "multiple antennas 240" is one or more antennas.

[0077] The plurality of antennas 240 can take a variety of forms. For example, the plurality of antennas 240 can be a plurality of dipole antennas 242. The antenna system 238 is configured to generate radiation 214 in the form of electromagnetic radiation 244. The electromagnetic radiation 244 has an electric field 246 and a magnetic field 248.

[0078] In these illustrative examples, electromagnetic radiation 244 may have a near field 250, a transition zone 252, and a far field 254. Near field 250 is the desired portion of electromagnetic radiation 244 that encompasses test object 218 in the illustrated example. In other words, near field 250 encompasses at least a portion of test object 218 such that current 216 flows in test object 218. Near field 250 is the portion of electromagnetic radiation 244 that is within about one wavelength of antenna system 238.

[0079] In these examples, if the electrical conductivity of the test sample is anisotropic or contains needle-like inclusions such as fibers where the electrical conductivity of the needle-like inclusions is greater than the rest of the material, the electric field 246 is preferably configured to be a larger component of the electromagnetic radiation 244 compared to the magnetic field 248 of the near field 250 of the electromagnetic radiation 244.

[0080] In these illustrative examples, electric field 246 is the component of electromagnetic radiation 244 that causes current 216 to flow in test object 218. Otherwise, magnetic field 248 is preferably configured to be a larger component of electromagnetic radiation 244 as compared to electric field 246 of near field 250 of electromagnetic radiation 244.

[0081] Additionally, if the test object 218 is composed of a ferromagnetic material, magnetostriction can be used to generate sound waves 222. In magnetostriction, a ferromagnetic material changes dimensions when an external magnetic field is applied. By varying the magnetic field at a certain frequency, magnetostriction can cause disturbances that propagate as sound waves.

[0082] In these embodiments, the conductive material 204 is not a permanent magnet. As a result, the magnetic field 212 is induced in the conductive material 204 prior to use of the electromagnetic acoustic transducer 200.

[0083] 9, a block diagram of a magnetic field-generating environment is shown in accordance with an advantageous embodiment. Magnetic field-generating environment 300 is configured to cause superconductor 302 to generate a magnetic field 304 having substantially fixed magnetic flux lines 306. More specifically, magnetic field-generating environment 300 can be used to cause superconductor 302 to have a trapped magnetic field 308.

[0084] As shown, the magnetic field generating environment 300 includes a temperature control system 310, a temperature control system 311, a magnetic field system 312, a current source 313, a holding structure 314, and a controller 316. The temperature control system 310 is configured to control a temperature 318 of the superconductor 302. The magnetic field system 312 is configured to generate a magnetic field 320. As shown, the magnetic field system 312 may be implemented using a superconducting magnet 321. This magnetic field is a second magnetic field. The magnetic field 320 is generated before the superconductor 302 generates the magnetic field 304, which is a first magnetic field. The holding structure 314 is configured to hold the superconductor 302. In particular, the holding structure 314 is configured to hold the superconductor 302 in a fixed position relative to the magnetic field system 312.

[0085] In this example, the temperature control system 310 is configured to change the temperature 318 of the superconductor 302 to a temperature greater than an operating temperature 322. The operating temperature 322 is a temperature at which the superconductor 302 has substantially zero resistance to electrical current. Additionally, the operating temperature 322 may also be a temperature at which the superconductor 302 has a sufficient current density to trap the magnetic field 304.

[0086] In these examples, the critical temperature may be the temperature at which superconductor 302 has substantially zero resistance to electrical current and a current density substantially equal to zero. Because operating temperature 322 is below the critical temperature of superconductor 302, a non-zero current density may exist to support a trapped magnetic field. Under these conditions, superconductor 302 may be a superconductor of a trapped magnetic field.

[0087] When temperature 318 is greater than operating temperature 322, controller 316 causes magnetic field system 312 to generate magnetic field 320. In particular, controller 316 can control current source 313 to send current to operate superconducting magnet 321 in magnetic field system 312 to generate magnetic field 320. In these illustrative examples, current source 313 is an alternating current source.

[0088] In this embodiment, temperature control system 311 is configured to cool magnetic field system 312. In particular, temperature control system 311 can maintain temperature 323 of superconducting magnet 321 at an operating temperature at which superconducting magnet 321 generates magnetic field 320 at a desired level.

[0089] While the magnetic field 320 is held constant, the controller 316 causes the temperature control system 311 to reduce the temperature 318 of the superconductor 302. In particular, the temperature 318 is reduced below the operating temperature 322 of the superconductor 302.

[0090] When the temperature 318 reaches or falls below the operating temperature 322, the controller 316 causes the magnetic field system 312 to reduce the magnetic field 320. In these examples, the magnetic field 320 can be about 10 Tesla (T). In some examples, the magnetic field 320 can range from about 2 Tesla to about 15 Tesla. Of course, other values ​​for the magnetic field 320 are possible, depending on the particular implementation.

[0091] The rate at which the magnetic field 320 is reduced may depend on the magnetic field system 312. For example, the superconducting magnet 321 may have superconducting wiring. The rate at which the magnetic field 320 may be reduced is a rate that avoids quenching of the superconducting wiring in the superconducting magnet 321. Quenching may occur when the superconducting wiring becomes resistive and no longer provides magnetic operation. This rate may be, for example, about 1 Tesla per 100 seconds. Of course, the rate may vary depending on the superconducting magnet 321.

[0092] At this point, the superconductor 302 may be used in an electromagnetic acoustic transducer, such as the electromagnetic acoustic transducer 200 of Figure 8. In some embodiments, rather than removing the superconductor 302 from the electromagnetic acoustic transducer, the entire electromagnetic acoustic transducer may be cooled.

[0093] The illustrations of the testing environment 1100 in FIG. 7, the electromagnetic acoustic transducer 200 in FIG. 8, and the magnetic field generating environment 300 in FIG. 9 are not meant to imply physical or architectural limitations to the manner in which an advantageous embodiment may be implemented. Other components in addition to and / or in place of those shown may be used. Some components may be unnecessary. Also, the blocks are presented to illustrate some functional components. One or more of these blocks may be combined, divided, or combined and then divided into different blocks when implemented in an advantageous embodiment.

[0094] For example, the data collector 1120 and the analyzer 1122 may be combined as a single component. In yet other embodiments, the vacuum system 208 may be omitted or may be implemented as part of the cooling system 210. In yet other embodiments, the current inducer 206 may be attached or incorporated as part of the housing 202 and / or another structure, depending on the particular implementation. In another example, the holding structure 314 may be part of the temperature control system 310.

[0095] In yet another example, although the conductive material 204 is shown as a superconductor 232, multiple superconductors may be used. In other words, multiple types of superconductors may be used, and multiple superconductor structures may be used. In addition to the superconductor 232, different types of superconductors and superconductor structures may be used to provide different orientations and patterns of the magnetic field 212.

[0096] Turning now to Figure 10, a cross-sectional view of an electromagnetic acoustic transducer is shown in accordance with an advantageous embodiment. In this example, electromagnetic acoustic transducer 400 is an implementation of electromagnetic acoustic transducer 124 in Figure 1, 200 in Figure 8, and 1134 in Figure 7.

[0097] In this cross-sectional view, the electromagnetic acoustic transducer 400 has a distance 402 from a test object 404 (which is an example of a component 102 shown in FIG. 1 ). In other words, the electromagnetic acoustic transducer 400 is not in physical contact with the test object 404.

[0098] As shown, the electromagnetic acoustic transducer 400 includes an electrically conductive material 405. In this example, the electrically conductive material 405 takes the form of a high temperature superconductor 406.

[0099] High temperature superconductor 406 has fixed magnetic flux lines, in other words, high temperature superconductor 406 has a trapped magnetic field that provides a magnetic field in the direction of arrow 407. In this example, arrow 407 is along the centerline of high temperature superconductor 406.

[0100] The high temperature superconductor 406 is cylindrical with a circular cross section. Of course, the high temperature superconductor 406 may have other cross-sectional shapes. For example, the shape may be square, pentagonal, hexagonal, or other suitable shape.

[0101] As shown, the high temperature superconductor 406 is in contact with the structure 408. More specifically, the high temperature superconductor 406 is in physical and thermal contact with the structure 408. In other words, heat can be conducted between the high temperature superconductor 406 and the structure 408.

[0102] In this example, structure 408 is configured to hold high temperature superconductor 406 within electromagnetic acoustic transducer 400. Structure 408 may be constructed from any material that conducts heat. As shown, structure 408 is constructed from copper. Clamp 410 holds high temperature superconductor 406 in place with respect to structure 408.

[0103] In these illustrative examples, structure 408 is coupled to a cooling system 416. In these illustrative examples, cooling system 416 includes a cryocooler 418. More specifically, cooling system 416 is thermally coupled to a coldhead 412 of cryocooler 418.

[0104] Cryocooler 418 may be implemented using any device configured to maintain the temperature of high temperature superconductor 406 at or below the operating temperature of high temperature superconductor 406 in these examples. As shown, cryocooler 418 may be mounted to a plate 420. Power connector 421 may be connected to a power source to provide power to operate cryocooler 418. Alternatively, cryocooler 418 may be a vessel with, for example, liquid nitrogen.

[0105] Additionally, the electromagnetic acoustic transducer 400 includes a housing 422. The housing 422 includes walls 424 and end caps 425 that define a cavity 426 in which the high temperature superconductor 406, the clamp 410, and a portion of the cold head 412 are disposed.

[0106] End cap 425 is removable. Removal of end cap 425 provides access to cavity 426. Cold head 412 extends into cavity 426 through an opening 428 in wall 424.

[0107] The cavity 426 may be a vacuum space in which a vacuum is created within the housing 422. Additionally, insulation 429 may be present within the cavity 426. The insulation 429 is configured to reduce heat transfer between the high temperature superconductor 406, the walls 424, and the end caps 425. The insulation 429 may take the form of a multi-layer insulation. The insulation 429 may be, for example, a sheet of aluminized biaxially oriented polyethylene terephthalate or other suitable type of insulation.

[0108] In this embodiment, a vacuum pump 430 is also attached to plate 420. Vacuum pump 430 is connected to housing 422 by tube 432. Once a vacuum is established in cavity 426, valve 434 can be closed to disconnect vacuum pump 430 from tube 432. In these embodiments, vacuum pump 430 and insulation 429 can reduce heat from reaching cold head 412 and high temperature superconductor 406.

[0109] As shown, current inducer 436 in electromagnetic acoustic transducer 400, in these examples, takes the form of a coil 437 and / or an antenna system 438. As shown, current inducer 436 may have element 439 and support structure 440. If current inducer 436 takes the form of coil 437, element 439 may be a coil winding for coil 437. If current inducer 436 takes the form of antenna system 438, element 439 may take the form of an antenna element. Additionally, current inducer 436 has wiring 442, which may be connected to a radio frequency signal generator.

[0110] A support structure 440 with elements 439 is disposed between the test object 404 and the end cap 425. In this embodiment, the antenna system 438 is not connected to the housing 422. Of course, in other embodiments, the support structure 440 for the antenna system 438 may be connected to the housing 422, the plate 420, or some other structure for positioning the antenna system 438.

[0111] In this embodiment, the antenna system 438 has a distance 444 to the high temperature superconductor 406. The distance 444 may be fixed or adjustable depending on the particular implementation.

[0112] With reference now to Figure 11, an illustration of an implementation of a magnetic field and generating environment is shown in accordance with an advantageous embodiment. In this example, magnetic field generating environment 500 is shown in cross section and is one implementation of magnetic field generating environment 300 in Figure 9.

[0113] As shown, magnetic field generating environment 500 includes a magnetic field system 502 in the form of a superconducting magnet 503. Additionally, in this example, temperature control system 504 includes a holding structure 506 configured to hold high temperature superconductor 406 in a fixed position while a magnetic field having substantially fixed magnetic flux lines is generated within high temperature superconductor 406.

[0114] In this embodiment, a support structure 506 with high temperature superconductor 406 is disposed inside a bore 510 of a superconducting magnet 503. The bore 510 may have a temperature that is substantially the same as the ambient temperature in these embodiments. In other words, the temperature within the bore 510 is independent of the temperature within the windings in the superconducting magnet 503.

[0115] In these examples, the holes 510 may have a diameter of greater than about 1 inch. Of course, the diameter may be any diameter that may be configured to receive the high temperature superconductor 406 and any components that hold the high temperature superconductor 406, such as the holding structure 506.

[0116] In this embodiment, the high temperature superconductor 406 initially has a temperature above its operating temperature. The superconducting magnet 503 operates to generate a magnetic field in the bore 510. The magnetic field increases to a magnetization value.

[0117] As shown, the magnetization value is the strength of the magnetic field that the HTS 406 is exposed to as the temperature of the HTS 406 decreases to an operating temperature. Additionally, in these embodiments, the magnetization value may be greater than the desired value of the trapped magnetic field within the HTS 406.

[0118] The magnetic field generated by the superconducting magnet 503 is held constant while the temperature of the high temperature superconductor 406 is reduced by the temperature control system 504. The temperature can be reduced to the operating temperature of the high temperature superconductor 406 or even lower, depending on the particular implementation. Once the high temperature superconductor 406 reaches its operating temperature, the magnetic field generated by the superconducting magnet 503 is reduced. In another embodiment, rather than ramping or reducing the magnetic field generated by the superconducting magnet 503, the high temperature superconductor 406 can be physically removed from the hole 510.

[0119] The high temperature superconductor 406 may then be moved within the housing 422 within the electromagnetic acoustic transducer 400, placed onto the structure 408, and held in place with the clamp 410 of FIG.

[0120] The movement of the high temperature superconductor 406 may be performed in a vacuum, dry atmosphere, or other suitable environment, and is performed in a manner that avoids increasing the temperature of the high temperature superconductor 406 such that the magnetic flux lines in the magnetic field generated by the high temperature superconductor 406 are no longer substantially fixed.

[0121] In a superconductor, the critical current density increases as the temperature is decreased from zero current density at the critical temperature to some value at absolute zero. In these examples, the critical current density is when the current density is strong enough to produce a non-zero electrical resistivity in the superconductor. The magnitude of the trapped magnetic field is approximately proportional to the current density. As a result, as the operating temperature is decreased, the strength of the trapped magnetic field increases. However, the trapped magnetic field cannot be higher than the magnetizing field in the examples. In some examples, the heat capacity decreases as the temperature is decreased. As a result, the superconductor may quench more easily than desired. As a result, a superconductor having a higher operating temperature is desirable.

[0122] The temperature control system 504 can be implemented in a number of different ways. For example, the temperature control system 504 can include a source of helium gas that flows through the holding structure 506 to the high temperature superconductor 406. Alternatively, a liquid can be used. For example, but not limited to, the liquid used in the temperature control system 504 can be liquid helium, liquid nitrogen, liquid hydrogen, liquid neon, liquid oxygen, and combinations of these liquids.

[0123] In other examples, the temperature control system 504 may include a liquid helium source through which helium 507 flows in contact with at least one of the holding structure 506 and the high temperature superconductor 406. In other examples, a cryocooler may be disposed in thermal contact with at least one of the holding structure 506 and the high temperature superconductor 406.

[0124] In this embodiment, the superconducting magnet 503 may be constructed from a number of different materials. For example, the superconducting magnet 503 may be constructed from NbTi or Nb3Nn. The superconducting magnet 503 may be cooled to an operating temperature via, for example, but not limited to, liquid helium, a superfluid helium cryostat, or a cryocooler.

[0125] In these examples, the magnetic field inside bore 510 of superconducting magnet 503 is in the direction of arrow 514 at centerline 516 of bore 510. As a result, the magnetic field generated by high temperature superconductor 406 is also along the direction of arrow 514.

[0126] 10 with the high temperature superconductor 406 can be placed in the hole 510 or the superconducting magnet 503 can be placed around the electromagnetic acoustic transducer 400. This type of arrangement avoids the need to move the high temperature superconductor 406 from the holding structure 506 to the housing 422.

[0127] As a result, the need to place the electromagnetic acoustic transducer 400 in a vacuum chamber to transfer the high temperature superconductor 406 from the holding structure 506 to the housing 422 can be avoided. In this embodiment, only the housing 422 may need to be within the bore 510. Other components, such as the cryocooler 418 and antenna system 438 of FIG. 10, may be on the fringe or outside of the bore 510.

[0128] In yet another embodiment, the high temperature superconductor 406 may be subjected to a series of pulses of a magnetic field generated by a magnet. In these embodiments, as the series of pulses are generated, the superconducting magnet 503 is replaced with a non-superconducting magnet. In the case of a pulsed magnetic field, the magnet used is not a superconducting magnet 503 in the embodiment. However, in some embodiments, a superconducting magnet 503 may be used.

[0129] In this embodiment, the high temperature superconductor 406 may be at or at a temperature substantially close to the operating temperature of the high temperature superconductor 406 when a pulse of a magnetic field is delivered to the high temperature superconductor 406 from a magnet used in place of superconducting magnet 503.

[0130] When a pulse of magnetic field is used to create a trapped magnetic field in the HTS 406, the magnetic field of the pulse is higher than if the magnetic field from the superconducting magnet 503 could be kept constant, and the temperature of the HTS 406 is reduced below the operating temperature of the HTS 406. These two conditions are used to obtain a trapped magnetic field in the HTS 406.

[0131] Turning now to Figure 12, a diagram of an antenna is shown in accordance with an advantageous embodiment. In this example, antenna 600 is an example of an antenna implementation in antenna system 438 of Figure 10. In this example, antenna 600 takes the form of a dipole antenna array 602. Antenna 600 includes antenna elements 604, 606, 608, 610, 612, 614, 616, and 618. In this example, the letter "A" refers to one terminal of a radio frequency signal generator and the letter "B" refers to another terminal of the radio frequency signal generator. The letters identify the terminals to which the various antenna elements are connected. In this example, the connection and arrangement of antenna elements 604, 606, 608, 610, 612, 614, 616, and 618 creates an electric field pattern having four rows of excitation. Each row is approximately 180 degrees out of phase with the other rows.

[0132] As shown, antenna element 604 and antenna element 606 form column 620. Antenna element 608 and antenna element 610 form column 622. Antenna element 612 and antenna element 614 form column 624, and antenna element 616 and antenna element 618 form column 626.

[0133] Of course, this illustration of antenna 600 is only one example, and any number of elements may be used in this exemplary configuration. Additionally, other configurations may be used with other types of antenna shapes.

[0134] 13, an illustration of an electric field aligned with a test object is shown in accordance with an advantageous embodiment. In this example, test object 700 has a layer 701 of carbon fibers 702. In these examples, carbon fibers 702 are aligned in the direction of arrow 704.

[0135] Carbon fibers 702 are conductive along their fiber length. For example, carbon fiber 706 is conductive along length 708. The different advantageous embodiments recognize and take into account that the fiber-to-fiber conductivity may not be as great as desired. For example, the conductivity from carbon fiber 706 to carbon fiber 710 may require more current than necessary to generate a signal large enough to detect the mismatch.

[0136] In an example, antenna 712 can be configured to generate electromagnetic radiation with an electric field having an electric field vector 714 that is substantially aligned in the direction of carbon fibers 702. In this manner, the electromagnetic radiation generated by antenna 712 can cause an electric current to flow in the direction of arrow 704 along each carbon fiber in carbon fibers 702.

[0137] Additionally, other layers of test object 700 may have carbon fibers with different orientations. Antenna 712 may be configured to selectively induce electrical currents in layers that have an orientation aligned with electric field vector 714. This electrical current may then interact with the magnetic field from the superconductor to induce a Lorentz force, which may result in acoustic waves within test object 700.

[0138] The component diagrams of Figures 10-13 may be combined with or used with the components shown in Figures 7-9, or a combination of the two. Additionally, some of the components shown in Figures 10-13 may be examples of how to implement as a physical structure the components shown in block form in Figures 7-9.

[0139] Furthermore, the illustrations of electromagnetic acoustic transducer 400 in Figure 10, magnetic field generating environment 500 in Figure 11, antenna 600 in Figure 12, and test object 700 in Figure 13 are not meant to imply physical or architectural limitations to the manner in which an advantageous embodiment may be implemented. These components are merely illustrative of one way in which an advantageous embodiment may be implemented.

[0140] Detection of sound waves using electromagnetic acoustic transducers can occur by monitoring changes in the magnetic field, electric field, or both, in response to the response of the sound waves traveling through the magnetic field and generating a current. The current has an electric field and a magnetic field. The electric field, the magnetic field, or both can be measured. In these examples, the measurement can be made via a current inducer, which can be a coil, an antenna, or other suitable device.

[0141] Advantageous embodiments of this disclosure may be described in the context of aircraft manufacturing and service methods and aircraft 1300, as shown in Figure 14. During prototyping, the aircraft manufacturing and service methods may include specification and design of aircraft 1300 and material procurement.

[0142] During production, component and subassembly manufacturing and system integration of the aircraft 1300 occurs. The aircraft 1300 can then go through certification and delivery and into service. While in customer service, the aircraft 1300 is scheduled for routine maintenance and service inspections, which may include modifications, reconfigurations, modifications, and other maintenance or service inspections.

[0143] 14 , aircraft 1300 includes an airframe 1302 with a number of systems 1304 and an interior 1306. Example systems 1304 may include one or more of a propulsion system 1308, an electrical system 1310, a hydraulic system 1312, and an environmental system 1314. Any number of other systems may be included. Although an aerospace example is shown, the different advantageous embodiments may be applied to other industries, such as the automotive industry.

[0144] Apparatus and methods implemented herein may be used during at least one stage of an aircraft manufacturing and service process to inspect aircraft 1300 or components of aircraft 1300. For example, ultrasonic inspection system 1108 of FIG. 7 may be used to perform non-destructive inspection on aircraft 1300 or components of aircraft 1300 during one or more stages of an aircraft manufacturing and service process. Use of some of the different advantageous embodiments may substantially expedite and / or reduce costs of assembly of aircraft 1300.

[0145] As described herein, embodiments of the present disclosure provide cost-effective and efficient non-destructive and non-contact systems and methods for inspecting additively manufactured components. The present disclosure further includes the following examples:

[0146] A1. A system for inspecting an additively manufactured component, the system comprising an additive manufacturing head that forms the component layer by layer and an electromagnetic acoustic transducer (EMAT) that inspects one or more layers of the component.

[0147] A2. The system of Example A1, further comprising a container defining a chamber, the additive manufacturing head configured to form a component within the container.

[0148] A3. The system of Example A2, wherein either the additive manufacturing head or the EMAT, or both, are within the chamber.

[0149] A4. The system of example A2 or A3, wherein one or both of the additive manufacturing head or the EMAT are movable relative to the chamber.

[0150] A5. The system of any one of Examples A1-A4, wherein the EMAT is configured to inspect one or more layers of the component as the component is formed by the additive manufacturing head.

[0151] A6. The system of any one of Examples A1 to A5, wherein the EMAT is configured to inspect one or more layers of the component after the one or more layers are formed by the additive manufacturing head.

[0152] A7. The system of any one of Examples A1 to A6, wherein the EMAT does not contact one or more layers of the component.

[0153] A8. The system of any one of Examples A1 to A7, further comprising an inspection control unit in communication with the EMAT, the inspection control unit configured to analyze inspection data relating to the one or more layers to determine the presence of one or more anomalies within or between the one or more layers, the inspection data being generated by the EMAT.

[0154] A9. The system of Example A8, wherein the test control unit is configured to output an alert to a user interface in response to detecting the presence of one or more anomalies.

[0155] A10. The system of example A9, wherein the alert includes one or both of an image or a description of the one or more anomalies.

[0156] A11. The system of any one of Examples A1 to A10, wherein the EMAT is coupled to an additive manufacturing head.

[0157] A12. The system of any one of Examples A1 to A11, wherein the EMAT is separate from the additive manufacturing head.

[0158] A13. The system of any one of Examples A1-A12, wherein the additive manufacturing head is movably coupled to a first support member and the EMAT is movably coupled to a second support member.

[0159] A14. The system of any one of Examples A1 to A13, wherein the EMAT is attached to an additive manufacturing head.

[0160] A15. The system of Examples A1-A14, wherein the additive manufacturing head is configured to move as the additive manufacturing head forms the component layer by layer.

[0161] A16. The system of Examples A1-A15, wherein the EMAT is configured to track the additive manufacturing head as the additive manufacturing head moves as the additive manufacturing head forms the component layer by layer.

[0162] A17. The system of example A16, wherein the EMAT is configured to inspect the component as the EMAT tracks the additive manufacturing head.

[0163] A18. A method for inspecting an additively manufactured component, the method including forming the component layer by layer with an additive manufacturing head, and inspecting one or more layers of the component with an electromagnetic acoustic transducer (EMAT).

[0164] A19. The method of example A18, wherein said forming step includes forming a component within a chamber of a container.

[0165] A20. The method of Example A19, further comprising disposing one or both of an additive manufacturing head or an EMAT in the chamber, and moving one or both of the additive manufacturing head or the EMAT relative to the chamber.

[0166] A21. The method of any one of Examples A18 to A20, wherein the inspecting step occurs during the forming step.

[0167] A22. A method according to any one of Examples A18 to A21, further comprising the steps of generating inspection data for one or more layers by an EMAT, analyzing the inspection data for the one or more layers by an inspection control unit in communication with the EMAT, and determining through the analyzing step the presence of one or more anomalies within or between one or more layers.

[0168] A23. The method of Example A22, further comprising outputting, by the test control unit, an alert to a user interface in response to detecting the presence of one or more anomalies.

[0169] A24. The method of any one of Examples A18-A23, wherein the forming step includes moving the additive manufacturing head.

[0170] A25. The method of any one of Examples A18-A24, wherein the inspecting step includes tracking the additive manufacturing head with an EMAT as the additive manufacturing head forms the component layer by layer.

[0171] A26. The method of example A25, wherein the inspecting step further comprises inspecting the component with an EMAT during the tracking step.

[0172] A27. A method for inspecting an additively manufactured component, the method including the steps of positioning an additive manufacturing head or an electromagnetic acoustic transducer (EMAT) or both within a chamber of a container; moving the additive manufacturing head or the EMAT or both relative to the chamber; forming a component layer by layer in the chamber by the additive manufacturing head; inspecting with the electromagnetic acoustic transducer (EMAT) during the step of forming one or more layers of the component; generating inspection data for the one or more layers by the EMAT; analyzing the inspection data for the one or more layers by an inspection control unit in communication with the EMAT; determining through the analyzing step the presence of one or more anomalies within or between the one or more layers; and outputting an alert to a user interface by the inspection control unit in response to detecting the presence of the one or more anomalies.

[0173] A28. The method of Example A27, wherein the forming step includes a step of moving an additive manufacturing head, and the inspecting step includes a step of tracking the additive manufacturing head with an EMAT as the additive manufacturing head forms the component layer by layer, and a step of inspecting the component with the EMAT during the tracking step.

[0174] B1. A system for inspecting an additively manufactured component, the system comprising: an additive manufacturing head that forms the component layer by layer, the additive manufacturing head moving as it forms the component layer by layer; and an electromagnetic acoustic transducer (EMAT) that inspects one or more layers of the component, the EMAT tracking the additive manufacturing head as it moves as it forms the component layer by layer, and the EMAT inspects the component as the EMAT tracks the additive manufacturing head.

[0175] B2. The system of Example B1, further comprising a container defining a chamber, the additive manufacturing head configured to form a component within the container.

[0176] B3. The system of example B2, wherein one or both of the additive manufacturing head or the EMAT are within the chamber.

[0177] B4. The system of any one of Examples B1 to B3, wherein the EMAT is configured to inspect one or more layers of the component after the one or more layers are formed by the additive manufacturing head.

[0178] B5. The system of any one of Examples B1 to B4, wherein the EMAT does not contact one or more layers of the component.

[0179] B6. The system of any one of Examples B1 to B5, further comprising an inspection control unit in communication with the EMAT, the inspection control unit configured to analyze inspection data relating to the one or more layers to determine the presence of one or more anomalies within or between the one or more layers, the inspection data being generated by the EMAT.

[0180] B7. The system of Example B6, wherein the test control unit is configured to output an alert to a user interface in response to detecting the presence of one or more anomalies.

[0181] B8. The system of example B7, wherein the alert includes one or both of an image or a description of the one or more anomalies.

[0182] B9. The system of any one of Examples B1 to B8, wherein the EMAT is coupled to an additive manufacturing head.

[0183] B10. The system of any one of Examples B1 to B9, wherein the EMAT is separate from the additive manufacturing head.

[0184] B11. The system of any one of Examples B1-B10, wherein the additive manufacturing head is movably coupled to a first support member and the EMAT is movably coupled to a second support member.

[0185] B12. The system of any one of Examples B1 to B11, wherein the EMAT is attached to an additive manufacturing head.

[0186] B13. A method for inspecting an additively manufactured component, the method comprising: forming the component layer-by-layer with an additive manufacturing head, the forming step comprising moving the additive manufacturing head; and inspecting one or more layers of the component with an electromagnetic acoustic transducer (EMAT), the inspecting step comprising tracking the additive manufacturing head with the EMAT as the additive manufacturing head forms the component layer-by-layer, and inspecting the component with the EMAT during the tracking step.

[0187] B14. The method of example B13, wherein said forming step includes forming a component within a chamber of a container.

[0188] B15. The method of example B14, further comprising disposing one or both of the additive manufacturing head or the EMAT in the chamber.

[0189] B16. The method of any one of Examples B13 to B15, wherein the inspecting step occurs during the forming step.

[0190] B17. The method of any one of Examples B13 to B17, further comprising the steps of generating inspection data for one or more layers by an EMAT, analyzing the inspection data for the one or more layers by an inspection control unit in communication with the EMAT, and determining through the analyzing step the presence of one or more anomalies within or between one or more layers.

[0191] B18. The method of Example B17, further comprising outputting, by the test control unit, an alert to a user interface in response to detecting the presence of one or more anomalies.

[0192] B19. A method for inspecting an additively manufactured component, the method including the steps of: positioning one or both of an additive manufacturing head or an electromagnetic acoustic transducer (EMAT) in a chamber of a container; moving both the additive manufacturing head and the EMAT relative to the chamber; forming a component layer-by-layer in the chamber by the additive manufacturing head; inspecting with the electromagnetic acoustic transducer (EMAT) during said step of forming one or more layers of the component; generating inspection data for the one or more layers by the EMAT; analyzing the inspection data for the one or more layers by an inspection control unit in communication with the EMAT; determining through said step of analyzing the presence of one or more anomalies in or between the one or more layers; and outputting an alert to a user interface by the inspection control unit in response to detecting the presence of the one or more anomalies.

[0193] B20. The method of Example B19, wherein the forming step includes a step of moving an additive manufacturing head, and the inspecting step includes a step of tracking the additive manufacturing head with an EMAT as the additive manufacturing head forms the component layer by layer, and a step of inspecting the component with the EMAT during the tracking step.

[0194] Various spatial and directional terms, e.g., top, bottom, bottom, middle, side, horizontal, vertical, front, etc., may be used to describe embodiments of the present disclosure, with it being understood that such terms are used solely with respect to the orientation shown, and that the orientation may be flipped, rotated, or otherwise changed so that top becomes bottom and vice versa, horizontal becomes vertical, etc.

[0195] As used herein, a structure, constraint, or element that is "configured to" perform a task or operation is specifically structurally formed, constructed, or adapted to correspond to the task or operation. For purposes of clarity and to avoid doubt, an object that can merely be modified to perform a task or operation is not "configured to" perform a task or operation as used herein.

[0196] It should be understood that the above description is intended to be illustrative and not limiting. For example, the above-described embodiments (and / or aspects thereof) can be used in combination with each other. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the various embodiments of the present disclosure without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the various embodiments of the present disclosure, the present embodiments are by no means limiting and are exemplary embodiments. Many other embodiments will be apparent to those skilled in the art upon review of the above description. The scope of the various embodiments of the present disclosure should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims and the detailed description herein, the terms "including" and "in which" are used as equivalents to the plain English terms "comprising" and "wherein," respectively. Additionally, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects. Moreover, the limitations of the following claims are not written in means-plus-function form and are not to be construed under 35 U.S.C. §112(f) unless such claim limitations expressly use the phrase "means for" following a recitation of a functional void of further structure.

[0197] This description uses examples to disclose various embodiments of the present disclosure, including the best mode, and also enables one of ordinary skill in the art to practice various embodiments of the present disclosure, including making and using any device or system, and performing any incorporated methods. The patentable scope of the various embodiments of the present disclosure is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. If an example has structural elements that do not differ from the literal language of a claim, or if the example includes equivalent structural elements that have insubstantial differences from the literal language of a claim, such other examples are intended to be within the scope of the claims. [Explanation of symbols]

[0198] 100 Inspection Systems 102 Components 104 Container 106 Base 108 Wall 110 Chamber 112 Additive Manufacturing Head 114 Emitter 116 Base Surface 118 Top surface 120 Building Direction 122 Formation Control Unit 124 Electromagnetic Acoustic Transducer (EMAT) 125 Acoustic Signals 126 Inspection Control Unit 127 Reflected acoustic signal 128 layers 130 User Interface 132 Display 140 Direction of movement 142 Actuator 144 Tracks

Claims

1. 1. A system (100) for inspecting an additively manufactured component (102), the system (100) comprising: an additive manufacturing head (112) for forming a component (102) layer by layer, the additive manufacturing head (112) being configured to move as the additive manufacturing head (112) forms the component (102) layer by layer; an electromagnetic acoustic transducer (EMAT) (124) for inspecting one or more layers (118) of the component (102); Equipped with The system (100), wherein the additive manufacturing head (112) is coupled to a first support member (160) and configured to move along the first support member (160), and the EMAT (124) is coupled to a second support member (162) and configured to move along the second support member (162).

2. 2. The system (100) of claim 1, further comprising a vessel (104) defining a chamber (110), wherein the additive manufacturing head (112) is configured to form the component (102) within the vessel (104), and wherein one or both of the additive manufacturing head (112) or the EMAT (124) are within the chamber (110), and one or both of the additive manufacturing head (112) or the EMAT (124) are movable relative to the chamber (110).

3. 3. The system (100) of claim 1 or 2, wherein the EMAT (124) is configured to inspect the one or more layers (118) of the component (102) as the component (102) is formed by the additive manufacturing head (112) and / or after the one or more layers (118) are formed by the additive manufacturing head (112).

4. 4. The system of claim 1, further comprising an inspection control unit in communication with the EMAT, the inspection control unit configured to analyze inspection data relating to the one or more layers to determine the presence of one or more anomalies within or between the one or more layers, the inspection data generated by the EMAT, and the inspection control unit configured to output an alert to a user interface in response to detecting the presence of the one or more anomalies, the alert including one or both of an image or a description of the one or more anomalies.

5. The EMAT (124) tracking the additive manufacturing head (112) as it moves as it forms the component (102) layer by layer; Inspecting the component (102) as the EMAT (124) tracks the additive manufacturing head (112). The system (100) of any one of claims 1 to 4, configured to:

6. 1. A method for inspecting an additively manufactured component (102), the method comprising: forming (170) a component (102) layer-by-layer by moving (112) along a first support member (160); inspecting (172) one or more layers (118) of the component (102) by moving an electromagnetic acoustic transducer (EMAT) (124) along a second support member (162); Including, The method, wherein the additive manufacturing head (112) is coupled to the first support member (160) and the EMAT (124) is coupled to the second support member (162).

7. The forming step (170) comprises: placing one or both of the additive manufacturing head (112) or the EMAT (124) in a chamber (110); moving one or both of the additive manufacturing head (112) or the EMAT (124) relative to the chamber (110); The method of claim 6, comprising forming the component (102) in the chamber (110) of a vessel (104) by

8. generating inspection data relating to the one or more layers (118) with the EMAT (124); analyzing the inspection data relating to the one or more layers (118) by an inspection control unit (126) in communication with the EMAT (124); determining (174) through the analyzing step the presence of one or more anomalies within or between the one or more layers (118); outputting (176) an alert to a user interface (130) in response to detecting the presence of the one or more anomalies by the test control unit (126); The method of claim 6 or 7, further comprising:

9. The forming step (170) includes moving the additive manufacturing head (112), and the inspecting step (172) includes: tracking the additive manufacturing head (112) with the EMAT (124) as the additive manufacturing head (112) forms the component (102) layer by layer; inspecting (172) the component (102) with the EMAT (124) during the step of tracking; The method according to any one of claims 6 to 8, comprising:

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