System and method for lightning strike protection

Abstract

A method of manufacturing a component for use in an aircraft, includes obtaining a composite panel of the aircraft and applying an ink to the panel to provide a coated panel. The ink comprises a metal compound, an organic amine, and a polymeric binder. The coated panel is subjected to sintering to yield the component.

Description

SYSTEM AND METHOD FOR LIGHTNING STRIKE PROTECTIONFIELD OF TECHNOLOGY

[0001] The present disclosure relates to lightning strike protection for aircraft components.BACKGROUND

[0002] Aircraft components are commonly made of composite materials such as carbon fiber-reinforced polymers to provide strength and rigidity while providing relatively low weight by comparison to metal components. Such composite materials are not good conductors and cannot conduct the electrical energy from a lightning strike or provide electromagnetic shielding, however. As a result, a lightning strike on a component of composite materials such as carbon fiber-reinforced polymer, results in damage to the component.

[0003] To improve conduction and dissipation of electrical energy due to a lightning strike, expanded metal foils are incorporated into the composite material and components of composite materials are electrically connected together. The addition of expanded metal foils and electrically joined components facilitate safe handling of current resulting from lightning strikes. Expanded metal foils are also useful for electromagnetic shielding, which is advantageous, particularly in components utilized in space.

[0004] In addition to the expanded metal foils, adhesives such as polymer adhesives, are utilized to join the expanded metal foils to the underlying composite structure. The adhesives also provide a surface for bonding of aerospace grade paints that may be made of polyurethane that provide protection against erosion and corrosion. The addition of expanded metal foils along with polymer adhesives, however, results in a significant increase in weight of the components and thus, a significant increase in weight of the overall structure.

[0005] Such increases in weight result in increased power for flight and a corresponding increase in the fuel utilized.

[0006] Improvements in lightning strike protection are desirable.SUMMARY

[0007] According to one aspect of an embodiment, there is provided a method of manufacturing a component for use in an aircraft, includes obtaining a composite panel of the aircraft and applying an ink to the panel to provide a coated panel. The ink comprises a metal compound, an organic amine, and a polymeric binder. The coated panel is subjected to sintering to yield the component.

[0008] A component for use in an aircraft includes a composite panel, a conductive metal coating disposed on the composite panel, the conductive metal coating comprising a conductive metal and a polymeric binder.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the present disclosure will now be described, by way of example only, with reference to the attached figure, in which FIG. 1 is a flowchart illustrating a method of manufacturing an aircraft component.DETAILED DESCRIPTION

[0010] Numerous details are set forth to provide an understanding of the examples described herein. The examples may be practiced without these details. In other instances, well-known methods, procedures, and components are not described in detail to avoid obscuring the examples described. The description is not to be considered as limited to the scope of the examples described herein.

[0011] Generally, the method of manufacturing a component for use in an aircraft, includes obtaining a composite panel of the aircraft, applying a metalcontaining ink to the panel to provide a coated panel, the metal-containing inkcomprising a metal compound, an organic amine, and a polymeric binder, and subjecting the coated panel to sintering to yield the component.

[0012] A flowchart showing a method of manufacturing an aircraft component is shown in FIG. 1. A panel is obtained for use in an aircraft at 102. The panel is a composite panel. The composite panel may be a carbon fiber-reinforced polymer (CFR.P) panel such as an epoxy-reinforced carbon fiber or a glass fiber reinforced plastic panel. Alternatively, the panel may be an uncured polymer matrix material or partially cured pre-preg material.

[0013] The panel may be subjected to ionizing discharge prior to applying metal-containing ink to facilitate adhesion of metal-containing ink to the panel. In particular examples, the ionizing discharge includes one or more of corona discharge, ozone, plasma treatment, or any combination thereof.

[0014] The metal-containing ink is applied to the panel at 104. The metalcontaining ink includes a metal-based compound, an amine, and a polymeric binder. The metal may be any metal-based compound, for example, silver, copper, aluminum, or any other suitable metal-based compound or combination of metal-based compounds.

[0015] The amine may be any suitable organic amine or combinations of amines, such as an alkylamine, a hydroxyalkylamine, or a cyclic amine, which may include from 2 to 12 carbon atoms. Some examples of alkylamines are 2- ethyl-l-hexylamine and 1-octylamine, 1-hexylamine. Examples of hydroxyalkylamines are 1,2-ethanolamine, 1-aminoisopropanol (amino-2- propanol ), 1,3-propanolamine, 1,4-butanolamine and amino propanediols (3- methyl amino propanediol, 3-(dimethylamino)-l,2-propanediol, 3- (diethylamino)-l,2-propanediol). Examples of cyclic amines are puridines pyrimidines, pyrroles, pyrrolidines, oxazolines, piperidines, isoxazoles, and morpholines.

[0016] The polymeric binder may be any suitable polymer such as a polyester, polyimide, polyether imide or any mixture thereof having functional groups thatrender the polymeric binder compatible with the organic amine. The polymeric binder may be dispersible, for example soluble, in the organic amine.

[0017] The polymeric binder may have similar or like chemical properties to the polymer utilized in the composite panel, facilitating adhesion between the metal-containing ink and the composite panel. The metal-containing ink includes sufficient polymer to bind the metal-containing ink to the panel. For example, the metal-containing ink may include about 1 wt.% to about 10 wt.% polymeric binder, to bond the metal-containing ink to the panel.

[0018] The metal-containing ink may also include a solvent compatible with the organic amine and polymeric binder. Suitable solvents include, for example, an organic solvent such as a non-aromatic organic solvent. Examples of such non-aromatic organic solvents include, for example, glycol ethers (e.g. dipropylene glycol methyl ether), alcohols (e.g. methylcyclohexanols, octanols, heptanols), carbitols (e.g., 2-(2-ethoxyethoxy) ethanol) or any mixture thereof. Alcohols may include Cl -CIO alkanols, such as octanols. When utilized, the solvent may be present in the ink in any suitable amount, such as about 1 wt. % to about 50 wt. %, based on total weight of the ink.

[0019] Examples of suitable metal-containing inks include a silver-containing ink with low viscosity and low processing temperature as disclosed in United States patent number 11,873,409 to Liu et al., or a printable conductive ink as disclosed in United State patent number 11,746,246 to Liu et al. The contents of United States patent number 11,873,409 to Liu et al. and United States patent number 11,746,246 to Liu et al. are incorporated herein in their entirety.

[0020] Examples of suitable metal-containing inks also include a Cu-containing ink such as that disclosed in United States patent number 11,525,066 to Kell et al., or a copper ink and conductive solderable copper traces produced therefrom as disclosed in United State patent number 10,844,238 to Deore et al. The contents of United States patent number 11,525,066 to Kell et al. and UnitedState patent number 10,844,238 to Deore et al. are incorporated herein in their entirety.

[0021] The metal-containing ink may therefore be a continuous layer, for example, applied by blade coating, slot-die coating, or spray coating, similar to a paint spray coating. Alternatively, the metal-containing ink may be patterned, for example by printing on the composite panel utilizing a screen-printing technique. Such patterning may be utilized, for example, for electromagnetic shielding, for example, for use in military applications, or for aerospace components utilized in space. Patterning of the conductive metal-containing ink may be utilized to further reduce the weight of the manufactured component.

[0022] The metal-containing ink may be applied to provide a conductive coating thickness of about 1 micron to about 15 microns after sintering. For example, a conductive coating thickness of about 3.5 microns to about 7 microns may be utilized to provide lightning strike protection. The thickness of the conductive coating may be dependent on the component being manufactured. The thickness of the conductive coating may be greater on components more susceptible to lightning strike on which greater conductivity is desired. For example, 200 kA protection is utilized for aircraft components in some areas of the aircraft while 100 kA protection is utilized for other aircraft components in other areas of the aircraft.

[0023] The metal-containing ink may optionally be dried, for example, for a period of time between 0 and 10 days to facilitate slow removal of high boiling point solvent to reduce the chance of cracks or voids in the resulting coating. To facilitate solvent removal, different methods such as infra-red light or moderate heating can be employed to reduce the period of time to a few minutes, in order to make the technology compatible with existing aerospace manufacturing practices, for example, composite manufacturing based on automated fiber placement (AFP) method.

[0024] Optionally, the metal-containing ink coated panel may be subjected to photonic treatment, such as ultraviolet treatment prior to heat treatment, for example, utilizing a UV conveyor such as a UV Conveyor 1 Ga-M-20 x7 at medium condition between 1 and 10 cycles. Other photonic treatment may alternatively or additionally employed, including near-infrared light treatment, and intense pulsed light treatment.

[0025] The metal-containing ink is subjected to sintering at 106. Sintering includes subjecting the coated panel including the metal-containing ink to heat treatment, for example, between 140°C and 200°C for a time period of between 30 minutes and 3 days. The sintering time and temperature utilized is dependent on the panel (substrate) material to which the metal-containing ink is applied and the metal-containing ink that is utilized. Examples of sintering time and temperatures are shown below in Table 3.

[0026] In the example in which the metal-containing ink is applied to an uncured polymer matrix material or partially cured pre-preg material, the sintering at 106 may be selected to also cure the polymer matrix material or partially cured pre-preg material while sintering the metal-containing ink. Alternatively, the ink may be cured with the curing of aerospace grade paint.

[0027] In addition, the panel may be subjected to intense pulse light (IPL) sintering to render the metal-containing ink coating conductive.

[0028] The resulting conductive metal-containing ink coating includes sufficient metal content to provide sufficient conductivity for lightning strike protection.For example, the conductive metal-containing ink coating may include about 95 wt% to about 99 wt% metal to provide conductivity similar to conductivity of a metal sheet.

[0029] The thickness of the conductive ink coating that results from sintering the conductive ink layer is controllable to tailor the thickness for the particular application (e.g., lightning strike protection based on different needs for lightningstrike protection in different airplane zones). Regions of an airplane that are subjected to lightning strikes are indicated by different zones in which:Zone 1 indicates an area likely to be affected by the initial attachment of a strike;Zone 2 indicates areas of swept, or moving, attachment; andZone 3 indicates areas that may carry the currents from lightning strike, which do not experience the actual attachment of a lightning strike.

[0030] The component is then provided for assembly in the manufacture of the aircraft.

[0031] The application of a highly conductive ink including a relatively small quantity of binder (polymer) significantly reduces the use of adhesive that is otherwise utilized to attach expanded metal foils to structure, resulting in significant weight reduction. A thin layer of ink, for example, a few micrometers, may be applied to composite structures to facilitate the passage of current during lightning strike or to absorbing magnetic waves during electromagnetic shielding. Unpatterned or patterned ink may be utilized for electromagnetic shielding. In contrast, the thickness of expanded metal foils is often limited to a lower limit thickness, for example, 20 micrometers, as the expanded metal foil is freestanding, unlike the use of ink. Further, the application of aerospace-grade paint, which may be made from polyurethane, on top of the ink may provide protection against corrosion, erosion, etc., and a cosmetic layer.Examples

[0032] The following examples are provided to further illustrate various aspects. These examples are intended to be illustrative and are not intended to be limiting.

[0033] Silver and copper-containing inks were initially utilized to test the effect of silver and copper thickness, ozone treatment, and sintering conditions on the performance of panels for lightning strike protection.

[0034] Ag-containing metal inks were formulated as set out in Table 1.TABLE 1

[0035] Conductive Cu-containing metal inks were formulated as set out in Table 2.TABLE 2

[0036] The silverand copper containing inks were mixed in a Teflon™ jar utilizing a Thinky™ mixer at a speed of 2000 rpm for about 20 minutes. The Teflon™ jar with ink was then wrapped in aluminum foil to protect the ink from light, and stored in a dry, dark location.

[0037] Carbon fiber reinforced polymer (CFR.P) samples were made from 24 layers of Cytec™ 977-2-IM7 pre-pregs. Each panel was made from quasi- isotropic layup of (45 / 90 / -45 / 0)3, followed by autoclaving according to recommended Cytec™ 977-2 curing protocol. In addition to the CFR.P panels fabricated for metal-containing ink coating, additional panels were fabricatedwith conventional lightning strike protection layer based on Cytec™ 905M ECS 015, according to SAE Zone 2A testing requirements.

[0038] Select CFR.P samples were pre-treated by reactive ozone treatment.

[0039] For the purpose of these examples, 10 to 15 pm thick tape was applied to the edges of the CFR.P panels to act as a spacer during the coating process. To increase thickness of the ink applied, multiple layers of tape were applied. Ink was then spread on the CFR.P panels as a uniform film utilizing a squeegee.

[0040] After coating with the ink, the panels were left in a fume hood to dry for one day.

[0041] The coated panels were subsequently UV dried utilizing DYMAX™ 5000- EC Series UV Curing Flood Lamp conveyor system in which the conveyor moved at 35 ft / min and was fitted with gallium-doped bulb at a medium condition setting for 5 cycles. The CFR.P was placed on a platform 20 cm from the lamp.

[0042] The coating that resulted from sintering was analyzed for its thickness, volume resistivity and adhesion using a scratch test. The resistivity values of the films were measured utilizing a four-point probe technique. The resistance was measured with a 4-point probe (SP4 four-point probe by Lucas Labs™) using a source meter in current mode (Keithley™ 220 programmable current source), and voltage was measured with an HP™ 3478A multimeter. A current of 100 mA was applied to the outer probes, and the voltage was measured on the inner probes. The sheet resistance was calculated from the resistance using a correction factor of 4.22. The resistivity was calculated from the sheet resistance (Rsh) by using Rsh = p / h, where p is the resistivity and h is the height of the sample. A CT-100 optical profiler by Cyber Technologies™ was used to determine the film thickness and calculate the volume resistivity. For each panel, the thickness was determined at at least three separate locations and averaged. A cross-hatch test was performed according to ASTM D 3359 to determine the adhesion of the metal coating on CFRP.

[0043] The treatments and results are detailed below in Table 3.TABLE 3

[0044] Lightning direct effects tests were performed on the panels to determine the efficacy of the applied protection against lightning strike damage. Three panel types were evaluated: (i) Unprotected baseline CFR.P, (ii) Conventional lightning strike protection film (Cytec™ 905M ECS 015) protected CFR.P, and (iii) Ag- and Cu- containing ink coated CFR.P. All panels were coated with aerospace-grade polyurethane paint and primer to ensure accurate simulation of the damage effects due to the artificial lightning. These tests were performed by Lightning Technologies™ (Pittsfield, MA) in accordance with thegeneral guidelines of SAE ARP5416, according to 2A zone criteria targeted at the center of the panels.

[0045] Table 4 shows the extent of CFRP damage after simulated lightning strike, determined utilizing ultrasonic inspection.TABLE 4Damage Damage Damage Weight depth area vol. penalty(mm) (cm2) (cm3) (g / m2)Baseline 1.8-2.1 46-50 3.0-3.4 N / ACFRP panel Panel + 0.7-0.8 37-57 0.9-1.5 280-Metal 350 foil* Panel + 1.6 33.7 2.7 58CuO Panel + 1.5 27.7 2.6 NAAg- 0-1Panel + 1.3 23.9 2.1 78Ag-0-2 Panel + 1.3 20.6 1.1 70Agl Panel + 2.0 19 1.1 40Ag2 Panel + 0.8 6.0 0.2 90Ag3 Panel + 3.5 50 1.9 160Ag4 Panel + 2.7 40 4.2 55Cui *Commercial method currently utilized for CFRP protection

[0046] The use of Rokrapol™ as well as ozone treatment was helpful to thesilver-containing ink adherence to the CFR.P panels. Low resistivity silver- containing films correlate to lower damage volume of CFR.P panels after simulated lightning strikes were carried out. Coatings prepared using the metalcontaining inks outperform the expanded metal foils when measured through damage volume / weight penalty.

[0047] Additional testing was carried out to determine the lightning strike performance of conductive metal coatings of different thicknesses to achieve high conductivity suitable for lightning strike protection, as well as adhesion throughout the panel. Different compositions of inks, and different coating methods and processing parameters were utilized. Table 5 shows the formulation of another silver-containing ink, referred to as Ink 8.

[0048] Prior to bar coating, the CFR.P were wiped with isopropanol, air dried and ozone treated between 5 and 30 minutes to facilitate coating adherence. Ozone treatment of 15 minutes provided good adherence.

[0049] The ink components were added to a container and subjected to planetary mixing until fully dissolved. The mixing was carried out at 2000 rpm for 10 mins, then at 2200 rpm for 30s.TABLE 5

[0050] The panel was coated using an SC-150 slot-die applicator attached to an automatic Research™ (GMBH) thin film coater and a Harvard Apparatus™ standard PHD 22 / 2000 syringe pump. The application achieved a measured sintered conductive coating thickness of 2 to 7 pm dependent on the coating speed, volumetric flowrate and blade gap of 50 to 200 pm. Once coated, the conductive ink coated CFRP panels were dried in a fume hood for nine days.

[0051] After drying and before sintering, the panels were UV dried utilizing a UV conveyor, DYMAX™ 5000-EC Series UV Curing Flood Lamp system. The conveyor moved at 35 feet per min and was fitted with gallium-doped bulb at medium condition for 7 cycles. The silver-containing conducting ink (Ink 8) coated CFRP panels were placed on top of a platform 20 cm from the lamp.

[0052] The dried conductive ink coated CFRP panels were then thermally sintered at 140°C (oven temperature) for 3 days followed by 170°C for 80 minutes using a reflow Sheldon™ oven, and then Intense pulsed light sintering (IPL— photonic sintering) was performed with a Novacentrix™ PulseForge™ 1300 system at voltage 280V for 1500 ps under atmospheric condition.

[0053] The conductive metal coating that resulted from sintering was analyzed for thickness, volume resistivity, and adhesion using a scratch test. The resistivity values of the films were measured using the four-point probe technique. The resistance was measured with a 4-point probe (SP4 four-point probe by Lucas Labs™) using a source meter in current mode (Keithley™ 220 programmable current source), and voltage was measured with an HP 3478A multimeter. A current of 100 mA was applied to the outer probes, and the voltage was measured on the inner probes. The sheet resistance was calculated from the resistance using a correction factor of 4.22. The resistivity was calculated from the sheet resistance (Rsh) by using Rsh = p / h, where p is the resistivity and h is the height of the sample. A CT-100 optical profiler by Cyber Technologies™ was utilized to determine the film thickness and calculate the volume resistivity. For each panel, the thickness was determined at at least threeseparate locations and averaged. A cross-hatch test was performed according to ASTM D 3359 to determine the adhesion of the metal coating on CFR.P.

[0054] Table 5 also shows the different formulation of a conductive silver ink, referred to herein as Ink 9.

[0055] Prior to bar coating, the CFR.P were wiped with isopropanol, air dried and ozone treated between 5 and 30 minutes to facilitate coating adherence. Ozone treatment of 15 minutes provided good adherence.

[0056] The ink components were added to a container and subject to planetary mixing until fully dissolved. The mixing was carried out at 2000 rpm for 10 mins, then at 2200 rpm for 30s.

[0057] The panel was coated using an SC-150 slot-die applicator attached to an automatic Research™ (GMBH) thin film coater and a Harvard Apparatus™ standard PHD 22 / 2000 syringe pump. The application achieved a measured sintered conductive metal coating thickness of 2 to 7 pm based on the coating speed, volumetric flowrate and blade gap of 50 to 200 pm after sintering.

[0058] The conductive ink coated CFRP panels were then thermally sintered at 150°C (oven temperature) for 30 minutes using a reflow Sheldon™ oven, and then Intense pulsed light sintering (IPL— photonic sintering) was performed with a Novacentrix™ PulseForge™ 1300 system at voltage 280V for 1500 ps under atmospheric condition.

[0059] The conductive metal coating that resulted from sintering was analyzed for thickness, volume resistivity, and adhesion using a scratch test. The resistivity values of the films were measured utilizing the four-point probe technique. The resistance was measured with a 4-point probe (SP4 four-point probe by Lucas Labs™) using a source meter in current mode (Keithley™ 220 programmable current source), and voltage was measured with an HP 3478A multimeter. A current of 100 mA was applied to the outer probes, and the voltage was measured on the inner probes. The sheet resistance was calculated from the resistance using a correction factor of 4.22. The resistivity wascalculated from the sheet resistance (R.sh) by using Rsh = p / h, where p is the resistivity and h is the height of the sample. A CT-100 optical profiler by Cyber Technologies™ was used to determine the film thickness and calculate the volume resistivity. For each panel, the thickness was determined at least three separate locations and averaged. A cross-hatch test was performed according to ASTM D 3359 to determine the adhesion of the metal coating on CFRP.

[0060] The treatments and results of the CFRP panels coated with Ink 8 and 9 are shown in Table 6.TABLE 6

[0061] Lightning direct effects tests were performed on the panels to determine the efficacy of the applied protection against lightning strike damage. Three panel types were evaluated: (i) Conventional lightning strike protection film with expanded copper foils (Cytec 905M ECS 015); (ii) Ink 8 (Table 5); (iii) Ink 9 (Table5).

[0062] All panels were coated with aerospace-grade polyurethane paint and primer to ensure accurate simulation of the damage effects due to the artificial lightning. These tests were performed by Lightning Technologies™ (Pittsfield, MA) in accordance with the general guidelines of SAE AR.P5416, according to 2A zone criteria targeted at the center of the panels. Ultrasonic inspections were carried out in pulse-echo mode from the back side of the panels. The inspections were carried out using a 3-axis gantry system with a 0.040 inch point step and increment spacing and a 5 MHz contact probe, coupled with water. C-scan images of the damage areas were generated. For each data point, the full waveform was recorded and damage depth was estimated based on the reflection. Maximum damage width, height, depth, and area were determined. In addition, the overall damage volume was obtained by integrating the depth over the damage area.

[0063] Table 7 shows the extent of CFR.P damage after simulated lightning strike, determined utilizing ultrasonic inspection.TABLE 7

[0064] Results from Table 7 show that both inks 8 and 9 provide enhanced protection against lightning by comparison to conventional lightning strike protection. The inks 8 and 9 provide enhanced protection by reducing the extent of CFRP damage due to simulated lightning strike at a fraction of weight penalty, i.e., 40-75 g / m2as opposed to 280 g / m2for conventional lightning strike protection.

[0065] In the above-described examples, the panel is a CFRR Alternatively, metal-containing ink may be applied to a thermoplastic-based laminate / tape. Conventional lightning strike protection may be difficult for such thermoplasticbased laminates / tapes as expanded metal foil does not bond well to thermoplastic-based laminates / tapes. The metal-containing ink, however, bonds well to thermoplastic-based laminates / tapes.

[0066] Advantageously, conductive ink may be applied to composite structures such as carbon fiber- reinforced polymer components for aircraft shell, for example, by blade or spray coating utilizing existing equipment such as painting equipment. When sintered and the components assembled, the conductive metal coating provides an electrical structure network facilitating safe handling of current produced by a lightning strike. The thickness of the conductive metal coating may be varied to provide greater thickness and increased protection on particular components.

[0067] The use of conductive metal coatings rather than an expanded metal foil applied to a composite result in a significant overall weight saving for the aircraft. In addition, the conductive metal coating may be patterned to increase the weight savings. The patterning may also be utilized for effective electromagnetic shielding.

[0068] The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

What is claimed is:Claims1. A method of manufacturing a component for use in an aircraft, the method comprising: obtaining a composite panel of the aircraft; applying an ink to the panel to provide a coated panel, the ink comprising a metal compound, an organic amine, and a polymeric binder; subjecting the coated panel to sintering to yield the component.

2. The method according to claim 1, wherein applying the ink comprises applying the ink having a metal loading of about 23 wt. % or more based on total weight of the ink, 5% wt.% to 50 wt.% organic amine, and 0.1 wt.% to 10 wt.% polymeric binder.

3. The method according to claim 1, wherein sintering the ink comprises sintering to provide a conductive metal coating having about 95 wt% to about 99 wt% metal.

4. The method according to claim 1, wherein applying the ink comprises at least one of spray coating, blade or bar coating, or slot-die coating the ink.

5. The method according to claim 1, wherein applying the ink comprises printing the ink.

6. The method according to claim 1, wherein applying the ink comprises patterning the ink.

7. The method according to claim 1, comprising determining a thickness of ink for application based on the component, wherein applying the ink comprises applying the conductive ink to provide the thickness determined based on the component.

8. The method according to claim 1, wherein sintering the ink comprises subjecting the panel including the ink to heat treatment.

9. The method according to claim 1, comprising subjecting the coated panel to air drying prior to sintering.

10. The method according to claim 1, comprising subjecting the coated panel to photonic treatment comprising at least one of ultraviolet light treatment, nearinfrared light treatment, or intense pulsed light treatment prior to subjecting the coated panel to sintering.

11. The method according to claim 1, comprising subjecting the composite panel to one or more of corona discharge, ozone, or plasma treatment prior to applying the ink.

12. The method according to claim 1, wherein the composite panel comprises a carbon fiber- reinforced plastic.

13. The method according to claim 1, wherein applying the ink comprises applying to provide a conductive metal coating thickness of about 1 micron to about 15 microns.

14. The method according to claim 1, wherein applying the ink comprises applying to provide a conductive metal coating thickness of about 3.5 micron to about 7 microns.

15. The method according to claim 1, wherein obtaining a composite panel comprises obtaining an uncured composite material or partially cured pre-preg material.

16. The method according to claim 15, wherein the composite panel is cured during subjecting the coated panel to sintering.

17. A component for use in an aircraft, the component comprising: a composite panel; a conductive metal coating disposed on the composite panel, the conductive metal coating comprising a conductive metal and a polymeric binder.

18. The component according to claim 17, wherein the conductive metal coating comprises about 95 wt% to about 99 wt% metal.

19. The component according to claim 17, wherein the conductive metal coating is patterned on the composite panel.

20. The component according to claim 17, wherein the composite panel comprises a carbon fiber-reinforced plastic.

21. The component according to claim 17, wherein the conductive metal coating is about 1 micron to about 15 microns in thickness.

22. The component according to claim 17, wherein the conductive metal coating is about 3.5 micron to about 7 microns in thickness.

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