Method and system for making conductor on substrate

Abstract

To provide a method and a system for making a conductor on a substrate.SOLUTION: A method (100) for making a conductor (304) on a substrate (302) by cold spray includes a step (104) for promoting solid powder composition containing copper and high orientation pyrolytic graphite by using a gas propellant, and a step (106) for facing the solid powder composition to the substrate (302) at speed enough to adhere to the substrate (302) by plastically deforming the solid powder composition in order to accumulate the conductor (304) on the substrate (302).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] SUMMARY This application relates to methods and systems for producing electrical conductors on a substrate and products formed therefrom. [Background technology]

[0002] Most electrical interconnects have a resistance of about 9g / cm 3 Copper (6×10 7 It is desirable to replace copper with a material that offers electrical performance equal to or better than copper, but that is much less dense.

[0003] Therefore, those skilled in the art continue to conduct research and development in the field of electrical conductor fabrication. Summary of the Invention [Means for solving the problem]

[0004] In one example, a disclosed method for producing an electrical conductor on a substrate by cold spray includes heating a gas propellant, propelling a solid powder composition including copper and highly oriented pyrolytic graphite using the heated gas propellant, and directing the solid powder composition toward a substrate at a velocity sufficient to plastically deform and adhere the solid powder composition to the substrate to deposit the electrical conductor on the substrate.

[0005] In one example, a disclosed system for spraying a coating material onto a substrate includes an optical sensor, a controller, a first regulator, a heater, a second regulator, and an actuator. The optical sensor is positioned to monitor a thickness of the coating material applied to the substrate. The controller communicates with the optical sensor and generates, based on the measured thickness, a first command signal corresponding to an amount of gas propellant to be heated, a second command signal corresponding to a temperature to which the gas propellant is heated, a third command signal corresponding to an amount of solid powder composition to be mixed with the heated gas in the nozzle, and a fourth command signal corresponding to a distance between the nozzle and the substrate. The first regulator receives the first command signal and supplies an amount of gas propellant corresponding to the first command signal. The heater receives the amount of gas propellant supplied from the first regulator and receives a second command signal to heat the gas propellant to a temperature corresponding to the second command signal. The second regulator receives a third command signal and supplies an amount of solid powder composition to the nozzle corresponding to the third command signal. The actuator receives a fourth command signal and moves the nozzle along the substrate a distance between the nozzle and the substrate that corresponds to the fourth command signal.

[0006] In one example, a disclosed cold spray coated product includes a substrate and an electrical conductor deposited on the substrate by cold spraying, the electrical conductor including a copper matrix and highly oriented pyrolytic graphite platelets dispersed in the copper matrix.

[0007] Other examples of the disclosed methods, systems, and articles of manufacture will become apparent from the following detailed description, the accompanying drawings, and the appended claims. [Brief description of the drawings]

[0008] [Figure 1] 1 is a flow chart illustrating an example of the disclosed method for creating electrical conductors on a substrate. [Diagram 2] 1 is a schematic diagram of an example of the disclosed system for spraying a coating material onto a substrate. [Diagram 3] FIG. 1 is a perspective view of an example of the disclosed cold spray coated product. [Figure 4] FIG. 1 is a flow diagram of an aircraft production and service method. [Diagram 5] FIG. 1 is a block diagram of an aircraft. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1 is a flow chart illustrating an example of a disclosed method 100 for producing an electrical conductor 304 (FIG. 3) on a substrate 302 (FIG. 3) by cold spraying. The method 100 includes steps 102 of heating a gas propellant, 104 of propelling a solid powder composition including copper and highly oriented pyrolytic graphite (HOPG) using the heated gas propellant, and 106 of directing the solid powder composition toward the substrate 302 at a velocity sufficient to plastically deform and adhere the solid powder composition to the substrate 302 to deposit the electrical conductor 304 on the substrate 302. By steps 104 of propelling the solid powder composition and steps 106 of directing it toward the substrate 302, the method 100 deposits the electrical conductor 304 from copper and highly oriented pyrolytic graphite on the substrate 302.

[0010] Heating the gas propellant, step 102, facilitates propelling the solid powder composition to a sufficient velocity, step 104. When heated, the gas propellant expands, thereby increasing the acceleration of the gas propellant and, consequently, the velocity of the solid powder composition. Furthermore, heating the gas propellant also heats the solid powder composition. Heating the solid powder composition facilitates plastic deformation of the solid powder composition and adhesion of the solid powder composition to the substrate 302 (FIG. 3) for depositing the electrical conductor 304 (FIG. 3) on the substrate 302 (FIG. 3).

[0011] The step 102 of heating the gas propellant can be performed in any manner. In one example, the gas propellant is heated to a suitable temperature by passing the gas propellant through a heat exchanger. In one example, the gas propellant is heated to a temperature in the range of 450 to 535° C. If the gas propellant is heated above 535° C., the solid powder composition may be adversely affected. In particular, the properties of the highly oriented pyrolytic graphite are degraded. Also, the substrate 302 (FIG. 3) may be degraded during deposition of the electrical conductor 304 (FIG. 3) thereon. If the gas propellant is insufficiently heated below 450° C., sufficient velocity of the gas propellant may not be achieved and the solid powder composition may not plastically deform and adhere to the substrate 302.

[0012] The step 104 of propelling the solid powder composition comprising copper and highly oriented pyrolytic graphite using a gas propellant can be performed in any manner. In one example, the gas propellant is accelerated to a high velocity by releasing the gas propellant from a high pressure state, such as a high pressure gas state, a liquid state, or a solid state. Before, after, or during the acceleration of the gas propellant, the gas propellant is mixed with the solid powder composition to propel the solid powder composition.

[0013] Step 106 of directing the solid powder composition toward the substrate 302 (FIG. 3) at a velocity sufficient to plastically deform the solid powder composition and adhere to the substrate 302 to deposit the conductor 304 (FIG. 3) on the substrate 302 can be performed in any manner. In one example, the solid powder composition is directed toward the substrate 302 using a nozzle, such as a Laval nozzle. Plastic deformation is a process in which a solid undergoes permanent deformation. Plastic deformation results in a permanent change in a solid without fracturing as a result of the application of stress beyond its elastic limit. In this description, the solid powder composition is directed toward the substrate 302 at a velocity sufficient to plastically deform the solid powder composition and adhere to the substrate 302 to deposit the conductor 304. By undergoing significant plastic deformation, the solid powder composition adheres to the substrate 302.

[0014] In one example, the solid powder composition is directed at the substrate 302 at a velocity of 500-1,000 m / s. If the velocity is less than 500 m / s, the solid powder composition may not undergo plastic deformation and may fail to properly adhere to the substrate 302 (FIG. 3). If the velocity is greater than 1,000 m / s, the substrate 302 may be damaged upon impact.

[0015] According to the present disclosure, the solid powder composition includes copper and highly oriented pyrolytic graphite. The copper may include pure copper, a copper-based alloy, or any alloy that includes copper. By selecting the solid powder composition to include copper, the solid powder composition may undergo plastic deformation upon impact with the substrate 302 (FIG. 3) and may adhere to the substrate 302. Additionally, the copper contributes to the high electrical conductivity of the resulting conductor 304 (FIG. 3) deposited on the substrate 302.

[0016] In one example, the current density in copper material is approximately 500 amperes per square centimeter (500A / cm 2 ), which makes it an ideal material for highly conductive matrix materials, especially in aircraft maintenance, aircraft repair, and aircraft life monitoring applications.

[0017] Highly oriented pyrolytic graphite (HOPG) is a very pure, ordered form of synthetic graphite. It is characterized by the International Union of Pure and Applied Chemistry (IUPAC) list of chemical terms as pyrolytic graphite with an angular spread of the crystallites' c-axes of less than 1 degree. Highly oriented pyrolytic graphite has high electrical conductivity. By selecting a solid powder composition to include highly oriented pyrolytic graphite, the conductor 304 from the solid powder composition deposited on the substrate 302 has high electrical conductivity.

[0018] In one example, the highly oriented pyrolytic graphite includes intercalated highly oriented pyrolytic graphite, such as bromine intercalated highly oriented pyrolytic graphite. The layered morphology of graphite allows different atomic or molecular species to be inserted between the graphite layers. The process of inserting such dopant species into graphite is called intercalation. Intercalation of highly oriented pyrolytic graphite is effective in changing the properties of highly oriented pyrolytic graphite. Bromine intercalated highly oriented pyrolytic graphite has been determined to be suitable for inclusion in the solid powder composition of the present disclosure. This is because bromine intercalated highly oriented pyrolytic graphite remains stable over long periods of time.

[0019] In one example, the copper particles are present in an amount of 55-65% by weight. If the copper particles are present in an amount less than 55% by weight, the highly oriented pyrolytic graphite is not fully captured in the copper matrix 306 (FIG. 3), and the adhesion of the conductor 304 to the substrate 302 (FIG. 3) is reduced. If the copper particles are present in an amount greater than 65% by weight, the overall conductivity of the conductor 304 (FIG. 3) is reduced and the weight of the conductor 304 increases.

[0020] In one example, the copper particles have an average particle size ranging from 15 μm to 25 μm. If the average particle size is less than 15 μm, the copper particles may not adhere to the substrate 302 (FIG. 3). If the average particle size is greater than 25 μm, the substrate 302 may be damaged upon impact.

[0021] In one example, the platelets of highly oriented pyrolytic graphite are included in the solid powder composition in an amount between 35-45% by weight. If the platelets of highly oriented pyrolytic graphite are included in the solid powder composition in an amount less than 35% by weight, the overall electrical conductivity of the conductor 304 (FIG. 3) decreases and the weight of the conductor 304 increases. If the platelets of highly oriented pyrolytic graphite are included in the solid powder composition in an amount greater than 45% by weight, the adhesion of the conductor 304 to the substrate 302 (FIG. 3) decreases.

[0022] In another example, the platelets of highly oriented pyrolytic graphite have an average platelet diameter in the range of 5 μm to 25 μm, which range has been determined to be optimal for maximum adhesion and maximum electrical conductivity of the conductor 304.

[0023] The gas propellant is any gas propellant suitable for propelling the solid powder composition. In one example, the gas propellant is an inert gas propellant. By selecting the gas propellant as an inert gas propellant, chemical reactions between the solid powder composition and the gas propellant can be avoided.

[0024] In another example, the inert gas propellant has an atomic number greater than 17. By selecting a gas propellant as an inert gas propellant having an atomic number greater than 17, the inert gas has a suitable high density sufficient to propel the solid powder composition. As an example, the inert gas propellant includes argon, which has an atomic number greater than 17 and is a high purity inert gas, resulting in less oxidation or trapped oxygen upon impact of the solid powder composition on the substrate 302 compared to helium or nitrogen. The use of argon, or other gas propellants having an atomic number greater than 17, also reduces the possibility of corrosion occurring due to the introduction of foreign metals (e.g., copper particles into a metal substrate) and maximizes the electrical conductivity of the highly oriented pyrolytic graphite by avoiding oxidation.

[0025] In another example, the conductor 304 (FIG. 3) has an average thickness T E The average thickness T EIf the average thickness T is less than 100 μm, the electrical conductivity of the conductor 304 (FIG. 3) decreases. E If the thickness is greater than 200 μm, the weight of the conductor 304 (FIG. 3) increases and the electrical conductivity enhancing effect of including highly oriented pyrolytic graphite begins to decrease.

[0026] FIG. 2 is a schematic diagram of an example of a system 200 that may be used to implement the method 100 shown in FIG.

[0027] 2, system 200 includes an optical sensor 216, a controller 218, a first regulator 204, a heater 206, a second regulator 210, and an actuator 214. System 200 may further include a third regulator 222, a fourth regulator 226, and a fifth regulator 230. System 200 may include additional components, such as additional regulators, without departing from the scope of the present disclosure.

[0028] The optical sensor 216 communicates with the controller 218 via a communication line 250, which may be wired or wireless, as may all communication lines 251, 252, 253, 254, 255, 260, 262 in the system 200. The optical sensor 216 measures the thickness T of the coating material 303 applied to the substrate 302. C The controller 218 may transmit data indicative of the measured thickness T of the coating material 303 applied to the substrate 302. C and based at least on operator input, the controller 218 generates command signals that control the amount of gas propellant heated, the temperature to which the gas propellant is heated, the amount of solid powder composition mixed with the heated gas in the nozzle 212, and the distance M between the nozzle 212 and the substrate 302.

[0029] The first regulator 204 communicates with the controller 218 via communication line 251. By controlling the first regulator 204, the amount of gas propellant supplied to the heater 206 can be controlled.

[0030] The heater 206 receives the gas propellant provided by the first regulator 204 and heats the gas propellant to a required temperature according to commands from the controller 218 via communication line 260 .

[0031] The second regulator 210 communicates with the controller 218 via a communication line 252. Control of the second regulator 210 controls the amount of solid powder composition introduced into the gas propellant.

[0032] The actuator 214 communicates with the controller 218 via communication lines 262. Command signals received by the actuator 214 from the controller 218 may move the nozzle 212 relative to the substrate 302. For example, the actuator 214 may move the nozzle 212 to achieve a desired distance M between the nozzle 212 and the substrate 302.

[0033] Thus, the system 200 can control the method 100 in real time to provide consistent results.

[0034] The system 200 may further include a tank 202 configured to store a gas propellant provided by the first regulator 204. In one embodiment, the tank 202 provides an inert gas propellant. In an exemplary embodiment, the tank 202 stores an inert gas propellant having an atomic number greater than 17 (e.g., argon).

[0035] The first regulator 204 includes any pressure or flow regulator that controls the output pressure or flow rate of a fluid to a desired value. For example, the first regulator 204 includes a valve. The output pressure or flow rate of the first regulator 204 can be adjusted based on a command signal received from the controller 218 via the communication line 251.

[0036] The heater 206 includes any heater capable of heating a gas to a controlled temperature. The temperature of the heater 206 may be adjusted based on command signals received from the controller 218 via communication line 260. In one example, the heater 206 is an electric heater. In another example, the heater 206 is a gas-fired heater.

[0037] The system 200 may further include a feeder 208. The feeder 208 is defined as any device for storing a solid powder composition. In one example, the feeder 208 stores a mixture of copper powder and platelets of highly oriented pyrolytic graphite as described above. Thus, to perform the method 100, the system 200 including the feeder 208 storing a solid powder composition may be employed. However, alternatively, the system 200 may include a feeder 208 storing a liquid composition such that the system 200 may be employed to perform different methods.

[0038] The second regulator 210 includes any pressure or flow regulator that controls the output pressure or flow rate of the fluid or the flow amount of the solid powder composition to a desired value. In one example, the second regulator 210 includes a valve and a mass sensor. Using the mass sensor, the second regulator 210 can accurately measure the amount of the solid powder composition passing through the second regulator 210. The amount of the solid powder composition passing through the second regulator 210 can be adjusted based on a command signal received from the controller 218 via the communication line 252.

[0039] The system 200 further includes a nozzle 212. The nozzle 212 may include any device suitable for ejecting the solid powder composition provided from the feeder 208 onto the substrate 302 using a heated gas propellant from the heater 206. In one example, the nozzle 212 includes a Laval nozzle used to accelerate hot pressurized gas passing through the Laval nozzle to supersonic velocities.

[0040] The actuator 214 may include any drive device suitable for moving the nozzle 212 along the substrate 302 at a predetermined distance M from the substrate 302. In one example, the actuator 214 may include a robotic actuator, such as a six-axis robotic actuator arm. Moving the nozzle 212 using the actuator 214 facilitates maintaining control of the distance M between the nozzle 212 and the substrate 302. For example, the distance M between the nozzle 212 and the substrate 302 is typically in the range of 1 to 100 mm, preferably 5 to 20 mm.

[0041] The optical sensor 216 detects the thickness T of the coating material 303 applied to the substrate 302. C and communicating (via communication line 250) with controller 218. Optical sensor 216, alone or in combination with controller 218, provides real-time visual material thickness measurements of the surface of substrate 302. In particular, the detection distance L0 between sensor 216 and substrate 302 obtained during an initial scan of substrate 302 is changed to the detection distance L0 between coating material 303 deposited on substrate 302 and sensor 216 during a subsequent scan. X By subtracting C For example, during an initial scan, the coating material 303 has not yet been deposited on the substrate 302, so the initial distance L represents the distance between the sensor 216 and the substrate 302. During subsequent scans, the distance L X represents the distance between the sensor 216 and the exposed surface 305 of the coating material 303. The thickness T C As increases, the distance L between the sensor 216 and the exposed surface 305 of the coating material 303 X It should be understood that decreases proportionally.

[0042] The exemplary optical sensor 216 is configured to measure the distance L from the optical sensor to the exposed surface 305 of the coating material 303. XThe optical distance sensor may be one or more optical distance sensors that use a pulsed light signal to generate a signal (input to the controller 218) representative of the applied thickness T of the coating material 303. The optical distance sensor works by pulsing a light emitting diode (LED) to shine light on a target surface (first the surface of the substrate 302 and then the exposed surface 305 of the coating material 303) and measuring the intensity of the reflected signal. Different reflectivities of the target surfaces will return different values ​​for the same distance. When the coating material 303 is applied to the substrate 302, the thickness T of the applied coating material is C As the distance L changes, X changes.

[0043] The controller 218 may be any device, system, multiple systems, or combination thereof (e.g., a microprocessor) capable of generating and transmitting command signals to obtain a desired result from a controlled device. As represented by the dotted lines in Figure 2, the controller 218 is communicatively coupled to the optical sensor 216, the first regulator 204, the second regulator 210, the heater 206, and the actuator 214.

[0044] In one example, the feeder 208 includes a first material feeder 220 that stores copper particles, a third regulator 222 that controls the amount of copper particles from the first material feeder 220, a second material feeder 224 that stores platelets of highly oriented pyrolytic graphite, a fourth regulator 226 that controls the amount of highly oriented pyrolytic graphite platelets from the second material feeder 224, and a mixer 228 that receives and mixes the copper particles provided by the third regulator 222 and the platelets of highly oriented pyrolytic graphite provided by the fourth regulator 226. Thus, the system 200 can regulate the relative amounts of copper particles and platelets of highly oriented pyrolytic graphite provided from the feeder 208.

[0045] The first material feeder 220 includes any device suitable for feeding copper particles, in one example, the first material feeder 220 is a gravity powder feeder.

[0046] The third regulator 222 includes any regulator suitable for controlling the flow rate of the copper particles to a desired value. In one example, the third regulator 222 includes a valve and a mass sensor. Using the mass sensor, the third regulator 222 can accurately measure the flow rate of the copper particles passing through the third regulator 222.

[0047] The second material feeder 224 includes any device suitable for storing platelets of highly oriented pyrolytic graphite. In one example, the second material feeder 224 is a gravity powder feeder.

[0048] The fourth regulator 226 includes any regulator suitable for controlling the flow rate of the highly oriented pyrolytic graphite platelets to a desired value. In one example, the fourth regulator 226 includes a valve and a mass sensor. Using the mass sensor, the fourth regulator 226 can accurately measure the flow rate of the highly oriented pyrolytic graphite platelets passing through the fourth regulator 226.

[0049] Mixer 228 includes any device suitable for mixing the copper particles passing from the third conditioner 222 and the highly oriented pyrolytic graphite platelets passing from the fourth conditioner 226. In one example, mixer 228 is a circular mixer.

[0050] In another example, a portion of the gas propellant provided from the tank 202 passes through a fifth regulator 230 (eg, a valve) and transports the solid powder composition provided from the feeder 208 to the nozzle 212 .

[0051] The thickness T of the coating material 303 measured by the optical sensor 216 CBy controlling the various functions of the system 200 using the controller 218 based on the above, the system 200 can control the process in real time to provide consistent results when making the cold spray coated product 300 using the method 100 as described in the following operational steps of the system 200.

[0052] The method of operation of the system 200 by the controller 218 includes measuring the thickness T of the coating material 303 applied to the substrate 302, such as by using an optical sensor 216. C This includes transmitting a signal to the controller 218 (via communication line 250) indicative of the measured thickness T, among other possible factors. C Based on the input from the controller 218 and the operator input, the controller 218 generates command signals to control the amount of gas propellant heated, the temperature to which the gas propellant is heated, the amount of solid powder composition mixed with the heated gas in the nozzle 212, and the distance M between the nozzle 212 and the exposed surface 305 of the coating material 303. The first regulator 204 receives the command signals and provides the required amount of gas propellant. The heater 206 receives the gas propellant provided by the first regulator and heats the gas propellant to the desired temperature. The second regulator 210 provides the required amount of solid powder composition. The actuator 214 moves the nozzle 212 according to the commands of the controller 218 to facilitate depositing the coating material 303 on the substrate 302.

[0053] As an example, the controller 218 may employ one or more of the following relationships to provide more consistent results to the system 200:

[0054]

number

[0055] V g -Gas velocity at the nozzle exit Temperature of the gas before it reaches the T-nozzle R-Ideal gas constant = 8.31 J / mol P e -Gas pressure at nozzle outlet = 1 / 5(P i *V i ) / (V e ) Optimization of metal matrix carbon-based composites V i -Volume at gas inlet V e - Volume at nozzle exit P i -Gas pressure supplied to the gun (optimum for argon / composite particles is 1-3MPa) M g -Molecular weight of gas γ-C p / C v (isentropic expansion coefficient) C p -Heat capacity of a gas at constant pressure (for argon, Cp=.52) C v -Heat capacity of a gas at constant volume (for argon, Cv=.312)

[0056]

number

[0057] V p -Particle velocity at nozzle exit C D - A constant assumed to be equal to 1 in this formula ρ g -Gas density ρ p -Average density of particles D p - Mean diameter of the particles x - distance M from nozzle to substrate ρ p =(%Wt m1 *ρ m1 )+[(1-(%Wt m1 ))*ρ m2 ] %Wt m1 - Weight percent of material used ρ m1 - Average density of particles in material 1 ρm2 -Average density of particles in material 2 M fp =(ρ p *V e ) / t M fp - Mass flow rate of particles at the nozzle exit t-time To summarise all this with respect to the system 200 described in this description:

[0058]

number

[0059] and

[0060]

number

[0061] The above equations may be utilized by the controller 218 using lookup tables for the gases and materials used, allowing the controller 218 to optimize the components of the system 200 in real time to meet the desired output parameters.

[0062] An exemplary specific method of operating system 200 to produce a cold sprayed product is provided as follows: Tank 202 is filled with a predetermined amount of propellant gas (e.g., argon) and feeder 208 stores a mixture of copper particles having a current density of 500 amps per square centimeter and platelets of highly oriented pyrolytic graphite intercalated with bromine.

[0063] An operator enters various initial inputs into the controller 218. For example, the operator may input the chemical composition of the substrate 302 and the desired thickness T of the conductor 304 (FIG. 3) to be formed on the substrate 302. E(FIG. 3), the chemical composition of the material in the first material feeder 220 (eg, copper) and the chemical composition of the material in the second material feeder 224 (eg, highly oriented pyrolytic graphite) are input into the controller 218.

[0064] Upon operation of the system 200, the optical sensor 216 begins to monitor the substrate 302 and the coating material 303 applied to the substrate 302. In real time, the optical sensor 216 measures the thickness T of the coating material 303 (if any) on the substrate 302. C The controller 218 transmits (via communication line 250) a signal indicating

[0065] The real-time measured thickness T of the coating material 303 on the substrate 302 C Based on various initial inputs entered by the operator, the controller 218 determines the desired thickness T E 3. The controller 202 generates various command signals that cause electrical conductors 304 (FIG. 3) having a capacitance C of 100 Ω or more on the substrate 302. The command signals are transmitted to the first regulator 204 (via communication line 251), to the second regulator 210 (via communication line 252), to the third regulator 222 (via communication line 253), to the fourth regulator 226 (via communication line 254), to the fifth regulator 230 (via communication line 255), to the heater 206 (via communication line 260), and to the actuator 214 (via communication line 262).

[0066] Command signals transmitted by controller 218 (via communication line 251) to first regulator 204 control the amount of gas propellant (supplied from tank 202) that is heated by heater 206. For example, a command signal received by first regulator 204 may cause first regulator 204 to partially or fully open, thereby allowing propellant gas (e.g., argon) to flow to heater 206.

[0067] Command signals transmitted by the controller 218 to the second regulator 210, the third regulator 222, the fourth regulator 226, and the fifth regulator 230 (via communication lines 252, 253, 254, 255, respectively) control the amount of solid powder composition mixed with the propellant gas and the chemical composition of the solid powder composition. For example, in the feeder 208, copper particles are fed from the first material feeder 220 to the mixer 228 and platelets of highly oriented pyrolytic graphite are fed from the second material feeder 224 to the mixer 228 based on material ratios entered by the operator into the controller 218. As an example, an operator may wish to make a conductor 304 (FIG. 3) having 55-65% copper and 35-45% highly oriented pyrolytic graphite by weight. In response to operator input, the controller 218 sends command signals (via communication line 253) to the third adjuster 222 and sends command signals (via communication line 254) to the fourth adjuster 226. The command signals (sent via communication lines 253, 254) function to operate the third adjuster 222 and the fourth adjuster 226, respectively, to ensure that desired amounts of both copper particles (in the first material feeder 220) and highly oriented pyrolytic graphite platelets (in the second material feeder 224) are delivered to the mixer 228. When the second adjuster 210 and the fifth adjuster 230 are at least partially open, the Cu / HOPG metal matrix composite material merges with the propellant gas (e.g., argon) and is delivered to the nozzle 212.

[0068] The command signal (sent via communication line 252) functions to operate second regulator 210 to ensure that an appropriate amount of the mixture of copper particles and highly oriented pyrolytic graphite platelets is mixed with the propellant gas (e.g., argon) passing through fifth regulator 230 and transferred to nozzle 212. At nozzle 212, the transferred mixture of copper particles and highly oriented pyrolytic graphite platelets is mixed with heated propellant gas from heater 206, which accelerates the mixture of copper particles and highly oriented pyrolytic graphite platelets to a velocity of 500-1,000 m / s. Thus, the mixture of copper particles and highly oriented pyrolytic graphite platelets is propelled using the heated gas propellant and directed by nozzle 212 toward substrate 302 at a velocity sufficient to plastically deform and adhere the solid powder composition to substrate 302 to deposit electrical conductor 304 on substrate 302.

[0069] Thus, the transport and composition of the material moving to the nozzle 212 can be controlled by the controller 218 by transmitting command signals to the first regulator 204, the second regulator 210, the third regulator 222, the fourth regulator 226, and the fifth regulator 230.

[0070] Command signals transmitted by the controller 218 to the heater 206 (via communication line 260) control the temperature to which the gas propellant is heated. For example, the controller 218 may instruct the heater 206 to heat to a temperature in the range of 450 to 535° C. Thus, the heater 206 heats the propellant gas (e.g., argon) to a temperature in the range of 450 to 535° C., and the heated propellant gas enters the nozzle 212.

[0071] Command signals transmitted by the controller 218 to the actuator 214 (via communication line 262 ) control the distance M between the nozzle 212 and the substrate 302 .

[0072] Thus, the controller 218 determines the thickness T of the coating material 303 on the substrate 302.C 2 and 3. The cold spray coated article 300 of FIG. 3 is formed, which includes a conductor 304 deposited on a substrate 302. The conductor 304 on the substrate 302 is formed to a desired thickness T with a desired chemical composition. E (FIG. 3). For example, the electrical conductor 304 includes a copper matrix 306 and highly oriented pyrolytic graphite platelets 308 dispersed in the copper matrix 306.

[0073] 3 is a perspective view of one example of a disclosed cold spray coated product 300. The cold spray coated product 300 includes a substrate 302 and a conductor 304 deposited on the substrate 302, such as by the method 100 using the system 200.

[0074] The substrate 302 may include any metallic substrate or any non-metallic substrate. Preferably, the substrate 302 is selected from a material suitable for withstanding the heat and shock applied by the cold spray process. In one example, the substrate 302 is a metallic substrate. In another example, the substrate 302 includes aluminum, titanium, or steel. In yet another example, the substrate 302 may be formed from aluminum alloy 7075 or aluminum alloy 7050.

[0075] The electrical conductor 304 includes a copper matrix 306 and highly oriented pyrolytic graphite platelets 308 dispersed in the copper matrix 306. Thus, the electrical conductor 304 provides a suitable alternative to conventional copper, having better electrical performance than copper and being less dense.

[0076] The copper matrix 306 includes pure copper, a copper-based alloy, or any alloy containing copper. By selecting the matrix as the copper matrix 306, the copper matrix 306 contributes to the high electrical conductivity of the electrical conductor 304.

[0077] In one example, the current density in the copper matrix 306 is approximately 500 amperes per square centimeter (500A / cm 2 ), which makes it an ideal material for highly conductive matrix materials, especially in aircraft maintenance, aircraft repair, and aircraft life monitoring applications.

[0078] In one example, the copper matrix 306 is present in the conductor 304 in an amount of 55-65% by weight. If the copper matrix 306 is present in an amount less than 55% by weight, the highly oriented pyrolytic graphite is not fully captured in the copper matrix 306 (FIG. 3), and the adhesion of the conductor 304 to the substrate 302 (FIG. 3) decreases. If the copper matrix 306 is present in an amount greater than 65% by weight, the overall conductivity of the conductor 304 (FIG. 3) decreases, and the weight of the conductor 304 increases.

[0079] In one example, the highly oriented pyrolytic graphite platelets 308 are included in the conductor 304 in an amount of 35-45% by weight. If the highly oriented pyrolytic graphite platelets 308 are included in the conductor 304 in an amount less than 35% by weight, the overall conductivity of the conductor 304 (FIG. 3) decreases and the weight of the conductor 304 increases. If the highly oriented pyrolytic graphite platelets 308 are included in the conductor 304 in an amount greater than 45% by weight, the adhesion of the conductor 304 to the substrate 302 (FIG. 3) decreases.

[0080] In one example, the highly oriented pyrolytic graphite platelet 308 comprises intercalated highly oriented pyrolytic graphite, such as highly oriented pyrolytic graphite intercalated with bromine. The layered morphology of graphite allows different atomic or molecular species to be inserted between the graphite layers. The process of inserting such dopant species into graphite is called intercalation. Intercalation of highly oriented pyrolytic graphite is effective to change the properties of the highly oriented pyrolytic graphite. Highly oriented pyrolytic graphite intercalated with bromine has been determined to be suitable for inclusion in the solid powder composition of the present disclosure.

[0081] In another example, the conductor 304 has an average thickness T E The average thickness T E If the average thickness T is less than 100 μm, the electrical conductivity of the conductor 304 decreases. E If the thickness is greater than 200 μm, the weight of the conductor 304 increases and the effect of the inclusion of highly oriented pyrolytic graphite in improving electrical conductivity begins to decrease.

[0082] In one example, the conductor 304 is 7×10 7 ~S / cm 3 More than 1×10 8 ~S / cm 3 More preferably, 1.4×10 8 ~S / cm 3 In another example, the electrical conductor 304 has a conductivity of 1.0 to 8.0 g / cm 3 in the range of 2.0 to 6.0 g / cm 3 more preferably in the range of 3.0 to 4.0 g / cm 3 Thus, the electrical conductor 304 may provide a much higher electrical conductivity and a much lower density than pure copper.

[0083] Examples of the disclosure may be described in the context of an aircraft manufacturing and service method 1000, as shown in Figure 4, and an aircraft 1002, as shown in Figure 5. During pre-production, the aircraft manufacturing and service method 1000 may include specification and design 1004 and material procurement 1006 of the aircraft 1002. During production, component / subassembly manufacturing 1008 and systems integration 1010 of the aircraft 1002 occurs. The aircraft 1002 may then undergo certification and delivery 1012 for entry into service 1014. While in service with a customer, the aircraft 1002 is scheduled for routine maintenance and service 1016, which may also include modifications, reconfigurations, and refurbishments.

[0084] Each process of method 1000 may be performed or carried out by a system integrator, a third party, and / or an operator (e.g., a customer). For purposes of this description, a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors, a third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers, and an operator may be an airline, a leasing company, the military, a maintenance contractor, etc.

[0085] The methods, systems, and products of the disclosure may be employed during any one or more stages of an aircraft manufacturing and maintenance method 1000, including specification and design 1004 of the aircraft 1002, material procurement 1006, component / subassembly manufacturing 1008, systems integration 1010, certification and delivery 1012, aircraft in-service 1014, and routine maintenance and service 1016.

[0086] 5 , the aircraft 1002 produced by the example method 1000 may include an airframe 1018 with a number of systems 1020 and an interior 1022. Examples of the number of systems 1020 may include one or more of a propulsion system 1024, an electrical system 1026, a hydraulic system 1028, and an environmental system 1030. Any number of other systems may be included. The methods, systems, and products of the present disclosure may be employed in any of the systems of the aircraft 1002.

[0087] Furthermore, the present disclosure includes embodiments according to the following clauses:

[0088] Clause 1. A method for producing an electrical conductor 304 on a substrate 302 by cold spray, the method comprising: heating the gas propellant; propelling a solid powder composition comprising copper and highly oriented pyrolytic graphite using a heated gas propellant; directing the solid powder composition toward the substrate 302 at a velocity sufficient to plastically deform the solid powder composition and cause it to adhere to the substrate 302 to deposit a conductor 304 on the substrate 302; A method comprising:

[0089] Clause 2. The current density of copper is approximately 500 amperes per square centimeter (500A / cm 2 2. The method according to claim 1, wherein

[0090] Clause 3. The method of clause 1, wherein the highly oriented pyrolytic graphite comprises bromine intercalated highly oriented pyrolytic graphite.

[0091] Clause 4. The method of clause 1, wherein the solid powder composition comprises particles of copper and platelets of highly oriented pyrolytic graphite.

[0092] Clause 5. The method of clause 4, wherein the copper particles are included in the solid powder composition in an amount of 55-65% by weight.

[0093] Clause 6. The method of clause 4, wherein the platelets of highly oriented pyrolytic graphite are included in the solid powder composition in an amount of 35-45% by weight.

[0094] Clause 7. The method of clause 4, wherein the copper particles have an average particle size in the range of 15 μm to 25 μm.

[0095] Clause 8. The method of clause 4, wherein the platelets of highly oriented pyrolytic graphite have an average platelet diameter of 5 μm to 25 μm.

[0096] Clause 9. The method of clause 1, wherein the gas propellant is an inert gas propellant.

[0097] Clause 10. The method of clause 9, wherein the inert gas propellant has an atomic number greater than 17.

[0098] Clause 11. The method of clause 9, wherein the inert gas propellant comprises argon.

[0099] Clause 12. The method of clause 1, wherein the gas propellant is heated to a temperature in the range of 450 to 535°C.

[0100] Clause 13. The conductor 304 has an average thickness T of 100 to 200 μm. E 2. The method of claim 1, comprising:

[0101] Clause 14. The method of clause 1, wherein the solid powder composition is directed toward the substrate 302 at a velocity of 500 to 1,000 m / s.

[0102] Clause 15. A system 200 for spraying a coating material 303 onto a substrate 302, the system comprising: The thickness T of the coating material 303 applied to the substrate 302 C an optical sensor 216 arranged to monitor the a controller 218 in communication with the optical sensor 216, the controller detecting the thickness T C a controller 218 for generating a first command signal 251 corresponding to an amount of gas propellant to be heated, a second command signal 260 corresponding to a temperature to which the gas propellant is heated, a third command signal 252 corresponding to an amount of solid powder composition to be mixed with the heated gas in the nozzle 212, and a fourth command signal 262 corresponding to a distance M between the nozzle 212 and the substrate 302 based at least on a first regulator 204 for receiving a first command signal 251 and for delivering an amount of gas propellant corresponding to the first command signal; a heater 206 that receives the amount of gas propellant provided by the first regulator and receives a second command signal 260 and heats the gas propellant to a temperature corresponding to the second command signal 260; a second regulator 210 receiving a third command signal 252 and supplying an amount of the solid powder composition to the nozzle 212 corresponding to the third command signal 252; an actuator 214 for receiving a fourth command signal 262 and for moving the nozzle 212 along the substrate 302 a distance M between the nozzle 212 and the substrate 302 in response to the fourth command signal 262; The system 200 comprises:

[0103] Clause 16. The system of clause 15, further comprising a tank 202 configured to store the gas propellant provided by the first regulator 204.

[0104] Clause 17. The system of clause 16, wherein the tank 202 supplies an inert gas propellant.

[0105] Clause 18. The system of clause 16, wherein the tank 202 supplies an inert gas propellant having an atomic number greater than 17.

[0106] Clause 19. The system of clause 16, wherein the tank 202 supplies argon.

[0107] Clause 20. The system of clause 15, wherein the first regulator 204 comprises a valve.

[0108] Clause 21. The system of clause 15, wherein the second regulator 210 comprises a valve and a mass sensor.

[0109] Clause 22. The system described in clause 15, further comprising a feeder 208 configured to store the solid powder composition provided by the second regulator 210.

[0110] Clause 23. The system of clause 22, wherein the feeder 208 stores a mixture of particles of copper and platelets of highly oriented pyrolytic graphite.

[0111] Article 24. Feeder 208: a first material feeder 220 for storing copper particles; a third regulator 222 for supplying a quantity of copper particles from the first material feeder 220; a second material feeder 224 for storing platelets of highly oriented pyrolytic graphite; a fourth regulator 226 for providing a quantity of highly oriented pyrolytic graphite platelets from a second material feeder 224; a mixer 228 for receiving and mixing the copper particles provided by the third conditioner 222 and the platelets of highly oriented pyrolytic graphite provided by the fourth conditioner 226; 24. The system of claim 23, comprising:

[0112] Clause 25. The system of clause 24, wherein the third regulator 222 comprises a valve and a mass sensor.

[0113] Clause 26. The system of clause 24, wherein the fourth regulator 226 comprises a valve and a mass sensor.

[0114] Clause 27. The system described in clause 15, wherein a portion of the gas propellant from the tank 202 passes through the fifth regulator 230 and transports the solid powder composition provided from the second regulator 210 to the nozzle 212.

[0115] Clause 28. A cold spray coated product 300, comprising: A substrate 302; a conductor 304 deposited on a substrate 302 by cold spray, the conductor 304 comprising a copper matrix 306 and highly oriented pyrolytic graphite platelets 308 dispersed in the copper matrix 306; The product 300 comprises:

[0116] Clause 29. The product of clause 28, wherein the substrate 302 is a metal substrate.

[0117] Clause 30. The article of clause 28, wherein the substrate 302 comprises aluminum, titanium, or steel.

[0118] Clause 31. The product of clause 28, wherein the current density of the copper matrix 306 is about 500 amperes per square centimeter.

[0119] Clause 32. The product of clause 28, wherein the copper matrix 306 is included in the conductor 304 in an amount of 55 to 65 weight percent.

[0120] Clause 33. The article of clause 28, wherein the highly oriented pyrolytic graphite platelets 308 comprise platelets of highly oriented pyrolytic graphite intercalated with bromine.

[0121] Clause 34. The product of clause 28, wherein the highly oriented pyrolytic graphite platelets 308 are included in the electrical conductor 304 in an amount of 35-45 weight percent.

[0122] Clause 35. The conductor 304 has an average thickness T of 100 to 200 μm. E 29. The method of claim 28, comprising:

[0123] Clause 36. The conductor 304 has a thickness of 3.0 to 4.0 g / cm 3 29. The product according to clause 28, having a density in the range

[0124] Clause 37. The conductor 304 has a resistance of 1.4×10 8 ~S / cm 3 28. A product as claimed in claim 28 having a conductivity of more than

[0125] While various examples of the disclosed methods, systems, and articles of manufacture have been shown and described, modifications will occur to those skilled in the art upon reading this specification, and the present application includes such modifications and is limited only by the scope of the claims. [Explanation of symbols]

[0126] 200 Systems 202 Tank 204 First Regulator 206 Heater 208 Feeder 210 Second Regulator 212 Nozzle 214 Actuator 216 Optical Sensor 218 Controller 220 First material feeder 222 The third regulator 224 Secondary Material Feeder 226 The Fourth Regulator 228 Mixer 230 The Fifth Regulator 250 communication lines 251 Communication line, first command signal 252 Communication line, third command signal 253 Communication Line 254 Communication Line 255 communication lines 260 Communication line, second command signal 262 Communication line, 4th command signal 300 cold spray coated products 302 Substrate 303 Coating materials 304 Conductors 305 Exposed surface 306 Copper Matrix 308 Highly oriented pyrolytic graphite platelets 1000 Maintenance and Inspection Methods 1002 Aircraft 1004 Specifications and Design 1006 Material Procurement 1008 Manufacturing of components / subassemblies 1010 System Integration 1012 Certification and Delivery 1014 Aircraft Launch 1016 Periodic maintenance and inspection 1018 Aircraft 1020 Multiple Systems 1022 Internal 1024 Propulsion System 1026 Electrical System 1028 Hydraulic System 1030 Environmental Systems L0 Detection distance between sensor and board L X Detection distance between the sensor and the coating material deposited on the substrate M Distance between nozzle and substrate T C The thickness of the coating material applied to the substrate T E Average Thickness

Claims

1. A method (100) for producing an electrical conductor (304) on a substrate (302) by cold spray, the method (100) comprising: Heating (102) a gas propellant; propelling (104) a solid powder composition comprising copper and highly oriented pyrolytic graphite using the heated gas propellant; directing (106) the solid powder composition toward the substrate 302 at a velocity sufficient to plastically deform the solid powder composition and cause it to adhere to the substrate 302 to deposit the electrical conductor 304 on the substrate 302; A method (100).

2. The step of propelling the solid powder composition comprises propelling the solid powder composition at 500 amperes per square centimeter (500 A / cm ２ 2. The method of claim 1, further comprising propelling a solid powder composition comprising copper having a current density of about 1000 .mu.m.

3. 3. The method (100) of claim 1 or 2, wherein the step of propelling the solid powder composition further comprises propelling a solid powder composition comprising highly oriented pyrolytic graphite comprising highly oriented pyrolytic graphite intercalated with bromine.

4. 4. The method (100) of any one of claims 1 to 3, wherein propelling the solid powder composition further comprises propelling a solid powder composition comprising particles of copper and platelets of highly oriented pyrolytic graphite.

5. 5. The method (100) of any one of claims 1 to 4, wherein the step of propelling the solid powder composition further comprises propelling a solid powder composition comprising particles of copper in an amount of 55-65 wt.% and platelets of highly oriented pyrolytic graphite in an amount of 35-45 wt.%.

6. 6. The method (100) of any one of claims 1 to 5, wherein propelling the solid powder composition further comprises propelling a solid powder composition comprising particles of copper having an average particle size in the range of 15 μm to 25 μm.

7. 7. The method (100) of any one of claims 1 to 6, wherein the step of propelling the solid powder composition further comprises propelling a solid powder composition comprising platelets of highly oriented pyrolytic graphite having an average platelet diameter of 5 μm to 25 μm.

8. 1. A system 200 for spraying a coating material 303 onto a substrate 302, the system comprising: The thickness T of the coating material 303 applied to the substrate 302 Ｃ an optical sensor 216 positioned to monitor a controller 218 in communication with the optical sensor 216, the controller Ｃ a controller 218 for generating a first command signal 251 corresponding to an amount of gas propellant to be heated, a second command signal 260 corresponding to a temperature to which the gas propellant is heated, a third command signal 252 corresponding to an amount of solid powder composition to be mixed with the heated gas in the nozzle 212, and a fourth command signal 262 corresponding to a distance M between the nozzle 212 and the substrate 302 based at least on a first regulator 204 for receiving the first command signal 251 and supplying an amount of gas propellant corresponding to the first command signal; a heater 206 that receives the amount of gas propellant provided by the first regulator, receives the second command signal 260, and heats the gas propellant to the temperature corresponding to the second command signal 260; a second regulator 210 receiving the third command signal 252 and supplying an amount of solid powder composition to the nozzle 212 corresponding to the third command signal 252; an actuator 214 for receiving the fourth command signal 262 and moving the nozzle 212 along the substrate 302 a distance M between the nozzle 212 and the substrate 302 in response to the fourth command signal 262; The system 200 comprises:

9. The feeder 208 stores the solid powder composition provided by the second regulator 210, the feeder 208 comprising: a first material feeder 220 for storing copper particles; a third regulator 222 for supplying a quantity of copper particles from the first material feeder 220; a second material feeder 224 for storing platelets of highly oriented pyrolytic graphite; a fourth regulator 226 for supplying a quantity of highly oriented pyrolytic graphite platelets from the second material feeder 224; a mixer 228 that receives and mixes the copper particles provided by the third adjuster 222 and the platelets of highly oriented pyrolytic graphite provided by the fourth adjuster 226; The system 200 of claim 8, comprising:

10. A cold spray coated product 300 made using the method (100) of any one of claims 1 to 7 or the system 200 of claims 8 or 9, said cold spray coated product comprising: A substrate 302; a conductor 304 deposited on the substrate 302 by cold spray, the conductor 304 comprising a copper matrix 306 and platelets 308 of bromine-intercalated highly oriented pyrolytic graphite dispersed in the copper matrix 306; The cold spray coated product 300 comprises:

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