Material coating system adapted to be removed by laser ablation

Abstract

The invention relates to a material coating system adapted to be removed by laser ablation. Examples disclosed relate to a material coating system (200) having properties that are adapted to be quickly removed by laser ablation. In one example, a material coating system (200) includes a substrate (202), a laser ablation layer (204) deposited on the substrate (202), and a topcoat layer (206) deposited over the laser ablation layer (204). The topcoat layer (206) is at least partially transparent to a laser light (108) of a specified wavelength. The laser ablative layer (204) is adapted to absorb the laser light (108) of a specified wavelength such that application of the laser light (108) of the specified wavelength onto the laser ablative layer (204) causes the laser ablative layer (204) and the topcoat layer (206) to jointly debond with the substrate (202).

Description

Technical Field

[0001] The present disclosure generally relates to the field of material coatings, and more particularly to removing material coatings from solid surfaces. Background Art

[0002] Removing material coatings, such as exterior decorative and non - decorative finishes, is a common practice as part of maintenance, repair, and overhaul (MRO) activities for objects coated with such material coatings, such as buildings or vehicles, e.g., aircraft. When an object is taken out of service for MRO activities, the loss of revenue or operational readiness is significant. Thus, as part of MRO activities, MRO technicians have an incentive to quickly remove these material coatings in order to return the object to service.

[0003] Conventional techniques for removing material coatings have various problems. One example is that material coatings can be removed from an object by abrasion or sanding. Conventional manual sanding lacks sufficient control to avoid damaging the underlying substrate of the object. When sanding is done by hand, the process is slow and poses an ergonomic challenge to the operator. In addition, the operator needs to wear a significant amount of personal protective equipment (PPE) to protect themselves from abrasive dust and / or other material particles generated during sanding, which increases the cost of conventional sanding.

[0004] Another example is that material coatings can be removed from an object by chemical stripping. Conventional chemical stripping requires a long dwell time for the chemicals to effectively strip the material coating from the object surface. In addition, conventional chemical stripping generates a large amount of hazardous waste that must be treated and disposed of through a carefully controlled process, which increases the cost of conventional chemical stripping. Also, the operator needs to wear a significant amount of PPE to protect themselves from the hazardous stripping chemicals and the chemical waste generated by conventional chemical stripping. Optionally, in order to avoid some of the problems associated with handling conventional stripping chemicals, environmentally sustainable strippers can also be used. However, the dwell time of such environmentally sustainable strippers is even longer than that of conventional stripping chemicals.

[0005] Yet another example is that a material coating can be removed from an object by a top-down laser material removal method. The top-down laser material removal method is achieved by setting the laser focus to the surface of the topmost material layer. With current laser technology, each time the laser passes, 25 - 50 microns of each layer is removed at a time. Laser material removal requires the laser to pass over the same area multiple times to remove the material layer by layer until the underlying substrate is exposed. Since the laser needs to pass multiple times to remove all the layers, the top-down laser material removal method is still very time-consuming - even though it offers additional advantages over conventional sanding and chemical stripping. By the top-down laser material removal method, more material can be removed with each pass, thus accelerating the entire process. For example, the laser power can be increased and / or the depth of the laser focus can be increased to remove more material with each pass. However, during the top-down laser material removal method, the adjustment of these laser operation parameters may cause laser damage to the underlying substrate. In addition, in some cases, the parameters of the laser may not be adjustable. Summary of the Invention

[0006] The disclosed examples relate to a material coating system having properties that are adjusted (tuned) to be rapidly removed by laser ablation. In one example, the material coating system includes a substrate, a laser ablation layer deposited on the substrate, and a topcoat layer deposited on top of the laser ablation layer. The topcoat layer is at least partially transparent to laser light of a specified wavelength. The laser ablation layer is adjusted to absorb laser light of the specified wavelength such that application of the laser light of the specified wavelength to the laser ablation layer causes the laser ablation layer and the topcoat layer to delaminate together from the substrate.

[0007] The features, functions, and advantages that have been discussed can be implemented independently in various embodiments or combined in still other embodiments, the further details of which can be seen with reference to the following description and the drawings. Brief Description of the Drawings

[0008] Figure 1 An example scenario of removing the layers of the disclosed material coating system from an aircraft by laser ablation is shown.

[0009] Figure 2 An example embodiment of the disclosed material coating system is schematically shown.

[0010] Figure 3 An example laser ablation layer of the disclosed material coating system is schematically shown, which is doped with an additive material configured to absorb laser light of a specified wavelength.

[0011] Figure 4 Schematically shows for removing Figure 2 an example of laser ablation of the layers of a material coating system.

[0012] Figure 5 Another example of laser ablation for removing layers of the different material coating systems of the present disclosure is schematically shown.

[0013] Figure 6 is a flow chart of an example method of producing the material coating system of the present disclosure. Detailed Description

[0014] Conventional techniques for removing material coatings from objects have various problems. For example, conventional sanding and chemical stripping are slow, cumbersome, and costly, and require the operator performing these processes to wear a large amount of personal protective equipment (PPE). Compared with conventional sanding and chemical stripping, the top-down laser material removal method offers multiple advantages. However, the top-down laser material removal method is still relatively slow and cumbersome.

[0015] Laser ablation is a technique that is becoming increasingly prominent in industrial hygiene and sustainability applications, and is particularly used for removing material coatings from solid surfaces. Laser ablation is a process in which a laser generates a highly concentrated and intense beam, which is directed onto the surface of the material to be ablated. The material absorbs the laser energy, and this absorption causes the material to undergo various physical and chemical changes. The absorbed laser energy depends on the laser parameters and the material and can lead to different processes. These processes may include heating, melting, vaporization, and ionization of the material. Due to the absorbed energy, the material either directly vaporizes into a plume of particles or undergoes a phase change, such as melting or sublimation. When the material undergoes a phase change, the material becomes detached from the target interface. Laser ablation provides a high degree of control and precision. The characteristics of the laser emitted by the laser, such as its intensity and duration, can all be carefully adjusted to achieve the desired material removal or modification while minimizing damage to the surrounding area. Laser ablation avoids the problems of conventional sanding and chemical stripping: it is faster and less laborious than hand sanding, and also has a shorter dwell time than chemical stripping. In addition, compared with conventional sanding and chemical stripping, laser ablation produces less waste. In addition, although the top-down laser material removal method provides additional advantages over conventional sanding and chemical stripping, the top-down laser material removal method is still time-consuming because the laser needs to pass over multiple times to remove all the material layers from the target interface.

[0016] Accordingly, it is desirable to remove a material coating from an object in a faster manner than other conventional methods while still protecting the underlying substrate of the object when removing the material coating from the substrate. Accordingly, examples of material coating systems are disclosed that have properties tuned for rapid removal by laser ablation. In one example, the material coating system includes a substrate, a laser ablation layer deposited on the substrate, and a topcoat layer deposited over the laser ablation layer. The topcoat layer is at least partially transparent to laser light of a specified wavelength. The laser ablation layer is tuned to absorb laser light of the specified wavelength such that application of the laser light of the specified wavelength to the laser ablation layer causes the laser ablation layer and the topcoat layer to delaminate together with the substrate.

[0017] Since the laser ablation layer is located below at least the topcoat layer (and in some embodiments also includes one or more additional intermediate layers), when the laser ablation layer absorbs the energy of the laser light of the specified wavelength and delaminates, the topcoat layer (and any intermediate layers) also separate from the underlying substrate. In this way, with each pass of the laser, multiple layers of the material coating system can be removed from the substrate. This allows the removal rate of the layers of the material coating system to be at least two to three times faster than top-down laser material removal methods. Additionally, the material coating system can still benefit from other advantages of laser ablation compared to conventional sanding and chemical stripping. For example, by using a laser-based material coating system, the time, cost, and labor associated with PPE required for conventional sanding and chemical stripping, as well as the disposal of hazardous waste, can be reduced or eliminated.

[0018] Figure 1 An example scenario of removing the layers of the material coating system of the present disclosure from an aircraft by laser ablation is shown. Aircraft 100 regularly undergoes MRO activities, one of which is removing and replacing the material coating on the outer surface 102 of aircraft 100. For example, the material coating can include exterior decorative and non-decorative finishes. In some examples, due to environmental exposure during operation of aircraft 100, the material coating can degrade over time and thus needs to be removed and replaced with an upgraded material coating. In other examples, aircraft 100 can be covered with a new livery having a different color scheme or design.

[0019] In the example shown, the outer surface 102 of aircraft 100 is coated with a material coating system 200. The material coating system 200 is configured to be removed from the outer surface 102 faster and more easily compared to other conventional methods. Specifically, the material coating system 200 includes a laser ablation layer 204 (as Figure 2 shown), which is tuned to absorb laser light 106 of a specified wavelength emitted from a laser 104 that is being used to remove the layers of the material coating system 200. The material coating system 200 is specifically configured such that one or more additional layers, herein referred to as topcoat layers (e.g.,Figure 2 the topcoat layer 206 shown in. When a laser 106 of a specified wavelength is emitted from the laser 104 and applied to the material coating system 200, the laser ablation layer 204 absorbs the energy from the laser, causing the laser ablation layer 204 and the additional topcoat layer 206 to debond from the underlying substrate 202 (as Figure 2 shown) together so as to be removed from the substrate 202 by laser ablation.

[0020] The laser 104 can be configured to perform any suitable removal operation / path to apply the laser to the material coating system 200 in order to remove the layers of the material coating system 200 from the aircraft 100. In one example, the laser 104 performs a scanning removal routine in which the laser 104 scans back and forth over the area 108 of the aircraft 100 in order to apply the laser to the area 108. Additionally, as part of the scanning routine, the laser 104 can make multiple passes over the same area 108 to ensure that the laser ablation layer 204 absorbs sufficient energy from the laser 106 to debond from the substrate 202.

[0021] In some embodiments, the laser 104 can be controlled in an automated manner. For example, the laser 104 can be included in a robotic system that can automatically perform laser ablation on the outer surface 102 of the aircraft. In other embodiments, the laser 104 can be manually controlled by a human operator. The laser 104 can take any suitable form.

[0022] The laser ablation layer 204 can be adjusted to absorb the energy of a laser of any suitable wavelength or wavelength range. In some examples, the laser 104 can be configured to emit infrared or near-infrared light (e.g., wavelength of ~1064 nanometers). As an example, a fiber laser can be used to remove the layers of the material coating system 200. The fiber laser uses ytterbium fiber as the laser material. Fiber lasers are efficient and are easy to repair on-site. In other examples, the material coating system 200 can be adjusted for use with different types of lasers that emit different wavelengths of laser, such as excimer lasers, CO2 lasers, fiber lasers, or another type of laser that emits different wavelengths of laser. The choice of laser depends on the specific requirements of the application, such as material properties, required precision, required ablation depth, and the allowable thermal effects on surrounding materials. An appropriate laser can be selected to optimize the efficiency and effectiveness of laser ablation for MRO activities performed on the aircraft 100.

[0023] Figure 1An example scenario is shown where a material coating system 200 that coats the outer surface 102 of an aircraft 100 is adjusted according to specific parameters of a laser 104 such that the layers of the material coating system 200 can be removed from the aircraft 100 by laser ablation in a faster manner than other conventional methods. The concepts discussed herein related to material coating systems configured for rapid removal by laser ablation are widely applicable to other applications beyond aircraft. In other embodiments, the material coating systems of the present disclosure can be applied to the surfaces of other types of vehicles or other structures and can still achieve the same benefits in terms of rapid removal by laser ablation.

[0024] Figure 2 An example embodiment of the material coating system 200 of the present disclosure is schematically shown. The material coating system 200 includes a substrate 202, a laser ablation layer 204, and a topcoat layer 206. The substrate 202 forms the structural base layer of the material coating system 200. In Figure 1 the example of the aircraft 100 shown, the substrate 202 corresponds to the outer surface 102 of the aircraft 100. The substrate 202 can include any suitable material. In some embodiments, the substrate 202 includes a metal alloy, such as aluminum or titanium. In other embodiments, the substrate 202 includes carbon fiber. Generally, when the layers of the material coating system 200 are removed by laser ablation, the substrate 202 remains intact in place as part of the underlying structure. Although in some embodiments, at least some portions of the substrate can be removed by laser ablation, this will be discussed in further detail below with reference to Figure 5 which will be discussed in further detail below.

[0025] In the material coating system 200, the laser ablation layer 204 is deposited on top of the substrate 202. The topcoat layer 206 is deposited on top of the laser ablation layer 204. The topcoat layer 206 is at least partially transparent to a specified wavelength of laser such that the specified wavelength of laser passes through the topcoat layer 206 and reaches the laser ablation layer 204. The specified wavelength refers to the wavelength of the laser that is emitted from the laser and applied to the material coating system 200 during the laser ablation process to remove the layers of the material coating system 200 from the substrate 202.

[0026] In some embodiments, the topcoat layer 206 can be completely transparent to the specified wavelength of laser. For example, the topcoat layer 206 can be a visually transparent varnish coating that is applied as a protective finish to protect the underlying layers of the material coating system 200 from environmental exposure.

[0027] In some embodiments, the topcoat layer 206 can be at least partially transparent to laser light of a specified wavelength, such that at least some of the laser light passes through the topcoat layer 206 to the laser ablation layer 204. For example, the topcoat layer 206 can include an amount of pigment that absorbs an amount of the laser light while still allowing an amount of the laser light to pass through the topcoat layer 206 to the laser ablation layer 204. In some embodiments, the topcoat layer 206 is a visually opaque coating layer.

[0028] In some embodiments, the topcoat layer 206 can be at least partially transparent to light of other wavelengths than the specified wavelength. In an embodiment, the topcoat layer 206 can absorb at least some of the light of other wavelengths than the specified wavelength.

[0029] In some embodiments, multiple topcoat layers 206, 206', 206" can be deposited over the laser ablation layer 204. Each of the multiple topcoat layers 206, 206', 206" is at least partially transparent to laser light of the specified wavelength to allow the laser light of the specified wavelength to pass through the multiple topcoat layers 206, 206', 206" to the laser ablation layer 204. As an example, different ones of the multiple topcoat layers 206, 206', 206" include pigments of different colors, which constitute Figure 1 the color scheme or a specific design of the paint job of the illustrated aircraft 100. In other examples, different ones of the multiple topcoat layers 206, 206', 206" can provide different features or functions. For example, different topcoat layers can provide different types of environmental element protection - e.g., ultraviolet protection, thermal protection, impact protection, or other types of protection. The material coating system 200 can include any suitable number and / or type of topcoat layers 206 deposited over the laser ablation layer 204.

[0030] The laser ablation layer 204 is tuned to absorb laser light of the specified wavelength such that applying the laser light of the specified wavelength to the laser ablation layer 204 causes the laser ablation layer 204 and the topcoat layer 206 (and topcoat layers 206', 206" when included) to delaminate together with the substrate 202. Thus, when the laser emits laser light onto the material coating system 200, multiple layers of the material coating system 200 can be removed from the substrate 202 based on each pass.

[0031] The laser ablation layer 204 can be tuned in any suitable manner to absorb laser light of the specified wavelength. In some embodiments, the laser ablation layer 204 can be selected or formulated to have material properties that absorb laser light of the specified wavelength.

[0032] In some other embodiments, the laser ablation layer 204 is doped with an additive material that is tuned to absorb laser light of the specified wavelength. Figure 3Schematically shows an example doped laser ablation layer 300 that may be included in a material coating system of the present disclosure. For example, the doped laser ablation layer 300 may correspond to Figure 2 The laser ablation layer 204 of the material coating system 200 shown. The doped laser ablation layer 300 includes a base material 302 doped with an additive material 304, and the additive material 304 is adjusted to absorb laser light of a specified wavelength. In some examples, the base material 302 itself has material properties that are adjusted to absorb laser light of a specified wavelength. In other examples, the base material 302 at least partially transmits or at least does not absorb laser light of a specified wavelength.

[0033] The additive material 304 may include any suitable type of material that is adjusted to absorb laser light of a specified wavelength. In some embodiments, the additive material 304 includes nanoscale particles. In some embodiments, the additive material 304 includes nanodiamonds that are adjusted (e.g., formulated or selected) to absorb laser light of a specified wavelength. In other embodiments, the additive material 304 includes carbon nanotubes that are adjusted (e.g., formulated or selected) to absorb laser light of a specified wavelength. In still other embodiments, the additive material 304 includes gold nanoparticles that are adjusted (e.g., formulated or selected) to absorb laser light of a specified wavelength. In still other embodiments, the additive material 304 includes nanoclay that is adjusted (e.g., formulated or selected) to absorb laser light of a specified wavelength. In still other embodiments, the additive material 304 includes micron-scale particles that are larger than the other nanoscale particles discussed above. For example, the micron-scale particles may include diamond, gold, clay, or other materials. The micron-scale particles are adjusted (e.g., formulated or selected) to absorb laser light of a specified wavelength. In still other embodiments, the additive material 304 includes graphene. In some embodiments, the laser ablation layer 300 is doped with multiple types of additive materials that are jointly adjusted to absorb laser light of a specified wavelength. For example, the laser ablation layer 300 may include any combination of the above additive materials and / or any other suitable additive materials. These different types of additive materials have different physical properties and respond differently to laser light of different wavelengths. The type of additive material used to dope the laser ablation layer may be selected based on the laser light of the specified wavelength and / or other factors. The nanoscale and / or micron-scale materials used in the material coating system may be applied sequentially in different layers, or may be combined into a "hybrid" layer as needed, or a combination of these, to achieve the performance required for coating removal. It should be noted that the particles of the additive material 304 are schematically shown and may assume a different shape than that depicted. For example, some types of particles may be planar rather than spherical.

[0034] Returning to Figure 2, in some embodiments, the material coating system 200 optionally further includes a reflective layer 208 deposited on the substrate 202 such that the reflective layer 208 is disposed between the laser ablation layer 204 and the substrate 202. In this embodiment, the laser ablation layer 204 is deposited on the reflective layer 208 rather than on the substrate 202. The reflective layer 208 is configured to reflect laser light of a specified wavelength. The reflective layer 208 provides various benefits. For example, the reflective layer 208 protects the substrate 202 from being degraded by the laser, so that the substrate 202 can remain intact after laser ablation. In some embodiments, the reflective layer 208 may have heat-absorbing properties to protect the substrate 202. In some embodiments, the reflective layer 208 may include nanoclay to enhance the heat-absorbing properties of the substrate 202. As another example, the reflective layer 208 reflects the laser light of a specified wavelength back to the laser ablation layer 204, so that when the laser passes through the laser ablation layer 204 for the second time after being reflected by the reflective layer 208, the laser ablation layer 204 can absorb more energy from the laser. Compared with the case where the material coating system 200 does not include the reflective layer 208, this increased absorption causes the laser ablation layer 204 and the topcoat layer 206 to debond from the substrate 202 even faster.

[0035] In some embodiments, the inclusion of the reflective layer 208 in the material coating system 200 may depend on the type of material that makes up the substrate 202. For example, if the substrate is formed as a monolithic component, such as using a metal alloy, the substrate is less likely to require repair or spot repair during MRO activities. In this case, there is no need to access the substrate during MRO activities, so the reflective layer can be included in the material coating system 200. On the other hand, sometimes the substrate may have known areas that need to be spot repaired as part of MRO activities. For example, such areas may include areas vulnerable to corrosion. In this case, the reflective layer can be omitted from the material coating system 200 so that these areas can be addressed as part of MRO activities. In some instances, these areas can be removed by laser ablation. Additionally, in some instances, the areas may include materials that are adjusted to absorb laser light of a specified wavelength in the same manner as the laser ablation layer 204, so that they can be debonded from the target interface together with the other layers of the material coating system 200 by laser ablation.

[0036] Figure 4Schematically shows an example of laser ablation for removing layers of a material coating system 200. At time T1, a laser 400 of a specified wavelength is emitted from a laser 402 and directed into the material coating system 200. The laser 400 travels through the topcoat layer 206 and into the laser ablation layer 204. As the laser 400 travels through the laser ablation layer 204, the laser ablation layer 204 absorbs the energy of the laser 400. The laser 400 is reflected from the reflective layer 208 and becomes a reflected laser 406. The reflected laser 406 is directed back through the laser ablation layer 204, where the laser ablation layer 204 can absorb additional energy from the reflected laser 406. The reflected laser 406 travels through the topcoat layer 206 and exits the material coating system 200. In some instances, the reflected laser 406 may be significantly absorbed by the laser ablation layer 204 such that a reduced amount of the reflected laser 406 exits the material coating system 200.

[0037] At time T2, the laser ablation layer 404 has absorbed sufficient energy from the laser 400 and the reflected laser 406 to begin to debond and blister from the reflective layer 208 and the substrate 202. The topcoat layer 206 remains bonded to the laser ablation layer 204, so the topcoat layer 206 also begins to blister from the reflective layer 208 and the substrate 202.

[0038] At time T3, the topcoat layer 206 and the laser ablation layer 204 have completely debonded and separated from the reflective layer 208 and the substrate 202 together. At this point, the laser ablation is complete, and the topcoat layer 206 and the laser ablation layer 204 can be removed together, leaving the reflective layer 208 and the substrate 202 in the material coating system 200 intact. Additionally, MRO activities can continue, applying a new laser ablation layer and a new topcoat layer to the remaining reflective layer 208 and substrate 202 to refinish the material coating system 200.

[0039] Since the laser ablation layer 204 and the topcoat layer 206 debond from the reflective layer 208 and the substrate 202 together, the laser ablation can be completed faster than other conventional coating removal methods. This enables the aircraft to undergo MRO activities and resume operational service faster than by performing other conventional material coating removal methods, which reduces the operating costs of the aircraft and provides other benefits.

[0040] Figure 5 Schematically shows another example of laser ablation for removing layers of a different material coating system 500 of the present disclosure. For example, the material coating system 500 can correspond to Figure 2The material coating system 200 shown in [figure]. The material coating system 500 includes a fibrous substrate 502, which includes layers of fiber bundles 502' and resin 502". In some embodiments, the fiber layer 502' includes carbon fiber bundles. In other embodiments, the fiber layer 502' includes glass fiber bundles. In some instances, the substrate 502 may include multiple fiber layers and resin layers. In some instances, the substrate 502 includes a glass fiber layer stacked on top of one or more carbon fiber layers (with resin layers in between). The material coating system 500 further includes a laser ablation layer 504 deposited on top of the substrate 502 and a topcoat layer 506 deposited on top of the laser ablation layer 504.

[0041] At time T1, a laser 508 of a specified wavelength is emitted from a laser 510 and directed into the material coating system 500. The laser 508 travels through the topcoat layer 506 and into the laser ablation layer 504. The focus or ablation plane 512 of the laser 510 is set at the depth of the top layer of the carbon fiber bundle 502'. As the laser 300 travels through the laser ablation layer 504, the laser ablation layer 504 absorbs the energy of the laser 508. The laser 508 further travels into the substrate 502 to reach the ablation plane 512. The top resin layer 502" of the substrate 502 is also adjusted to absorb the energy of the laser 508 of the specified wavelength.

[0042] At time T2, the laser ablation layer 504 and the top resin layer 502" of the substrate 502 have absorbed enough energy from the laser 508 to begin to debond and blister from the top carbon fiber layer 502' of the substrate 502. The topcoat layer 506 remains bonded to the laser ablation layer 504, and the laser ablation layer 504 remains bonded to the top resin layer 502", so the topcoat layer 206 also begins to blister from the substrate 502.

[0043] At time T3, the topcoat layer 506, the laser ablation layer 504, and the top resin layer 502" have been debonded and separated from the substrate 502 together. At this point, the laser ablation is complete, and the topcoat layer 506, the laser ablation layer 504, and the top resin layer 502" can be removed together, and the fiber layer 502' and the rest of the substrate 502 in the material coating system 500 will remain intact. In addition, MRO activities can continue, applying a new resin layer, a new laser ablation layer, and a new topcoat layer to the remaining layers of the substrate 502 to refinish the material coating system 500.

[0044] In the illustrated example, the resin layer 502" is removed during laser ablation to expose the fiber layer 502' of the substrate. There are various reasons for removing the resin layer 502' from the substrate 502. As an example, the resin layer 502" may be replaced due to environmental exposure during the operation of the material coating system. As another example, when the aircraft reaches the end of its operating life cycle, the aircraft can be disassembled, recycled, or disposed of. During disassembly, the resin layer 502" can be removed by laser ablation for proper recycling or disposal of the materials.

[0045] Figure 6 is a flowchart of an example method 600 for producing the material coating system of the present disclosure. For example, the method 600 can be executed to produce Figure 2 the material coating system 200 shown in or another material coating system.

[0046] In some embodiments, at 602, the method 600 can include applying a reflective layer over a substrate of the material coating system. The reflective layer is configured to reflect a laser of a specified wavelength.

[0047] In some embodiments, at 604, the method 600 can include doping the laser ablation with an additive material configured to absorb a laser of a specified wavelength. In some embodiments, at 606, the additive material can include nanoscale particles. In some embodiments, the nanoscale particles can include at least one of nanodiamonds, carbon nanotubes, gold nanoparticles, graphene, and nanoclays. In some embodiments, at 608, the additive material can include micron-scale particles. In some embodiments, the micron-scale particles can include at least one of diamond, gold, graphene, and clay. In some embodiments, at 610, the additive material can include a mixture of nanoscale particles and micron-scale particles. In some embodiments, the laser ablation layer can be doped with multiple types of additive materials that are jointly tuned to absorb a laser of a specified wavelength. For example, the laser ablation layer can include any combination of the above additive materials and / or any other suitable additive materials. These different types of additive materials have different physical properties and react differently to lasers of different wavelengths. The type of additive material used to dope the laser ablation layer can be selected based on the laser of the specified wavelength and / or other factors. The nanoscale and / or micron-scale materials used in the coating system can be applied sequentially in different layers or can be combined into a "hybrid" layer or a combination thereof as needed to achieve the desired performance for coating removal.

[0048] In other embodiments, the laser ablation layer can be tuned in a different manner that does not involve doping the laser ablation layer with an additive material. Instead, the material properties of the laser ablation layer itself can be selected / manufactured to absorb a laser of a specified wavelength.

[0049] At 612, method 600 includes applying a laser ablation layer over a substrate. In some embodiments where the material coating system includes a reflective layer, at 614, method 600 may include applying the laser ablation layer over the reflective layer.

[0050] At 616, method 600 includes applying one or more topcoat layers over the laser ablation layer in the material coating system. In some embodiments, at 618, the topcoat layer may include a visually transparent clear coat layer. In some embodiments, at 620, the topcoat layer may include a visually opaque paint layer.

[0051] The above method can be implemented to produce a material coating system where the laser ablation layer is located below at least the topcoat layer (and in some embodiments also includes one or more additional intermediate layers). When the laser ablation layer absorbs energy from a laser of a specified wavelength and debonds, the topcoat layer (and any intermediate layers) also separate from the underlying substrate. Thus, during laser ablation, multiple layers of the material coating system can be removed from the substrate with each pass of the laser. This allows the layers of the material coating system to be removed more quickly than other conventional methods.

[0052] In one example, a material coating system includes a substrate, a laser ablation layer deposited on the substrate, and a topcoat layer deposited over the laser ablation layer, where the topcoat layer is at least partially transparent to a specified wavelength of laser, and where the laser ablation layer is tuned to absorb the specified wavelength of laser such that application of the specified wavelength of laser to the laser ablation layer causes the laser ablation layer and the topcoat layer to debond from the substrate together. In this example and / or other examples, the laser ablation layer may be doped with an additive material that can be tuned to absorb the specified wavelength of laser. In this example and / or other examples, the additive material may include nanoscale particles. In this example and / or other examples, the nanoscale particles may include at least one of nanodiamonds, carbon nanotubes, gold nanoparticles, graphene, and nanoclay. In this example and / or other examples, the additive material may include micron-scale particles. In this example and / or other examples, the additive material may include a mixture of nanoscale particles and micron-scale particles. In this example and / or other examples, the topcoat layer may be a visually transparent clear coat layer. In this example and / or other examples, the material coating system may further include a reflective layer deposited between the laser ablation layer and the substrate and configured to reflect the specified wavelength of laser. In this example and / or other examples, the substrate may include a metal alloy. In this example and / or other examples, the substrate may include a fiber layer and a resin layer, and the resin layer may be tuned to absorb the specified wavelength of laser such that application of the specified wavelength of laser to the resin layer causes the resin layer to debond from the fiber layer of the substrate.

[0053] In another example, the process of fabricating a material coating system includes applying a laser ablation layer over a substrate and applying a topcoat layer over the laser ablation layer, where the topcoat layer is at least partially transparent to a specified wavelength of laser, and where the laser ablation layer is tuned to absorb the specified wavelength of laser such that application of the specified wavelength of laser to the laser ablation layer causes the laser ablation layer and the topcoat layer to delaminate together with the substrate. In this example and / or other examples, the process of fabricating a material coating system may further include applying a reflective layer over the substrate and applying a laser ablation layer over the reflective layer. In this example and / or other examples, the process of fabricating a material coating system may further include doping the laser ablation layer with an additive material that is tuned to absorb the specified wavelength of laser. In this example and / or other examples, the additive material may include nanoscale particles. In this example and / or other examples, the nanoscale particles may include at least one of nanodiamonds, carbon nanotubes, gold nanoparticles, graphene, and nanoclays. In this example and / or other examples, the additive material may include micron-scale particles. In this example and / or other examples, the additive material may include a mixture of nanoscale particles and micron-scale particles. In this example and / or other examples, the topcoat layer may be a visually transparent varnish coating. In this example and / or other examples, the substrate may include a fiber layer and a resin layer, and the resin layer may be tuned to absorb the specified wavelength of laser such that application of the specified wavelength of laser to the resin layer causes the resin layer to delaminate from the fiber layer of the substrate.

[0054] In yet another example, a material coating system includes a substrate, a reflective layer deposited on the substrate, a laser ablation layer deposited on the reflective layer, and a topcoat layer deposited over the laser ablation layer, where the topcoat layer is at least partially transparent to a specified wavelength of laser, and where the laser ablation layer is doped with an additive material that is tuned to absorb the specified wavelength of laser such that application of the specified wavelength of laser to the laser ablation layer causes the laser ablation layer and the topcoat layer to delaminate together with the substrate, and where the reflective layer is configured to reflect the specified wavelength of laser.

[0055] Specifically, the present invention includes the following clauses.

[0056] 1. A material coating system, comprising:

[0057] A substrate (202);

[0058] A laser ablation layer (204) deposited on the substrate (202); and

[0059] A topcoat layer (206) deposited over the laser ablation layer (204),

[0060] wherein the topcoat layer (206) is at least partially transparent to a laser (106) of a specified wavelength, and

[0061] wherein the laser ablation layer (204) is adjusted to absorb the laser (106) of the specified wavelength such that application of the laser (106) of the specified wavelength to the laser ablation layer (204) causes the laser ablation layer (204) and the topcoat layer (206) to delaminate together with the substrate (202).

[0062] 2. The material coating system (200) according to clause 1, wherein the laser ablation layer (204) is doped with an additive material (304) that is adjusted to absorb the laser (106) of the specified wavelength.

[0063] 3. The material coating system (200) according to clause 2, wherein the additive material (304) comprises nanoparticles.

[0064] 4. The material coating system (200) according to clause 3, wherein the nanoparticles comprise at least one of nanodiamond, carbon nanotube, gold nanoparticle, graphene, and nanoclay.

[0065] 5. The material coating system (200) according to clause 2, wherein the additive material (304) comprises micron-sized particles.

[0066] 6. The material coating system (200) according to clause 2, wherein the additive material (304) comprises a mixture of nanoparticles and micron-sized particles.

[0067] 7. The material coating system (200) according to clause 1, wherein the topcoat layer (206) is a visually transparent varnish coating.

[0068] 8. The material coating system (200) according to clause 1, further comprising:

[0069] a reflective layer (208) deposited between the laser ablation layer (204) and the substrate (202) and configured to reflect the laser (106) of the specified wavelength.

[0070] 9. The material coating system (200) according to clause 1, wherein the substrate (202) comprises a metal alloy.

[0071] 10. The material coating system (200) according to clause 1, wherein the substrate (502) comprises a fiber layer (502') and a resin layer (502''), and wherein the resin layer (502'') is adapted to absorb the laser (508) of the specified wavelength such that application of the laser (508) of the specified wavelength to the resin layer (502'') causes delamination of the resin layer (502'') from the fiber layer (502') of the substrate (502).

[0072] 11. A method for manufacturing a material coating system (200), the method comprising:

[0073] Applying a laser ablation layer (204) over a substrate (202); and

[0074] Applying a topcoat layer (206) over the laser ablation layer (204),

[0075] wherein the topcoat layer (206) is at least partially transparent to a laser (108) of a specified wavelength, and

[0076] wherein the laser ablation layer (204) is adapted to absorb the laser (108) of the specified wavelength such that application of the laser (108) of the specified wavelength to the laser ablation layer (204) causes delamination of the laser ablation layer (204) and the topcoat layer (206) together from the substrate (202).

[0077] 12. The method for manufacturing the material coating system (200) according to clause 11, further comprising:

[0078] Applying a reflective layer (208) over the substrate (202); and

[0079] Applying the laser ablation layer (204) over the reflective layer (208).

[0080] 13. The method for manufacturing the material coating system (200) according to clause 11, further comprising:

[0081] Doping the laser ablation layer (204) with an additive material (304), the additive material (304) being adapted to absorb the laser (108) of the specified wavelength.

[0082] 14. The method for manufacturing the material coating system (200) according to clause 12, wherein the additive material (304) comprises nano-sized particles.

[0083] 15. The method of manufacturing the material coating system (200) according to clause 12, wherein the nanoscale particles include at least one of nanodiamond, carbon nanotube, gold nanoparticle, graphene, and nanoclay.

[0084] 16. The method of manufacturing the material coating system (200) according to clause 12, wherein the additive material (304) includes micron-scale particles.

[0085] 17. The method of manufacturing the material coating system (200) according to clause 12, wherein the additive material (304) includes a mixture of nanoscale particles and micron-scale particles.

[0086] 18. The method of manufacturing the material coating system (200) according to clause 11, wherein the topcoat layer (206) is a visually transparent varnish coating.

[0087] 19. The method of manufacturing the material coating system (200) according to clause 11, wherein the substrate (502) includes a fiber layer (502') and a resin layer (502''), and wherein the resin layer (502'') is adjusted to absorb the laser (108) of the specified wavelength, such that application of the laser (108) of the specified wavelength to the resin layer (502'') causes delamination of the resin layer (502'') from the fiber layer (502') of the substrate (502).

[0088] 20. A material coating system (200), comprising:

[0089] A substrate (202);

[0090] A reflective layer (208) deposited on the substrate (202);

[0091] A laser ablation layer (204) deposited on the reflective layer (208); and

[0092] A topcoat layer (206) deposited on the laser ablation layer (204),

[0093] wherein the topcoat layer (206) is at least partially transparent to a laser (108) of a specified wavelength,

[0094] wherein the laser ablation layer (204) is doped with an additive material (304), the additive material (304) being adjusted to absorb the laser (108) of the specified wavelength, such that application of the laser (108) of the specified wavelength to the laser ablation layer (204) causes delamination of the laser ablation layer (204) and the topcoat layer (206) together from the substrate (202), and

[0095] Wherein the reflective layer (208) is configured to reflect the laser (108) of the specified wavelength.

[0096] It will be understood that the configurations and / or methods described herein are exemplary in nature, and these specific embodiments or instances should not be considered restrictive as numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Accordingly, the various acts shown and / or described may be performed in the order shown and / or described, in other orders, in parallel, or omitted. Similarly, the order of the above processes may be changed.

[0097] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems, and configurations, as well as other features, functions, acts, and / or characteristics disclosed herein, and any and all equivalents thereof.

[0098] Parts list:

[0099] Aircraft 100 Outer surface 102 Laser 104 Laser beam 106 Area 108 Material coating system 200 Substrate 202 Laser ablation layer 204 Topcoat layer 206 Reflective layer 208 Doped laser ablation layer 300 Base material 302 Additive material 304 Laser beam 400 Laser 402 Laser ablation layer 404 Reflected laser beam 406 Material coating system 500 Substrate 502 Fiber layer 502' Resin layer 502'' Laser ablation layer 504 Topcoat layer 506 Laser beam 508 Laser 510 Ablation plane 512

Claims

1. A material coating system, comprising: a substrate (202); a laser ablation layer (204) deposited on the substrate (202); and a topcoat layer (206) deposited on top of the laser ablation layer (204), wherein the topcoat layer (206) is at least partially transparent to a laser (106) of a specified wavelength, and wherein the laser ablation layer (204) is adapted to absorb the laser (106) of the specified wavelength such that application of the laser (106) of the specified wavelength to the laser ablation layer (204) causes the laser ablation layer (204) and the topcoat layer (206) to delaminate from the substrate (202) together.

2. The material coating system (200) according to claim 1, wherein the laser ablation layer (204) is doped with an additive material (304), the additive material (304) being adapted to absorb the laser (106) of the specified wavelength.

3. The material coating system (200) according to claim 2, wherein the additive material (304) comprises nano-sized particles.

4. The material coating system (200) according to claim 3, wherein the nano-sized particles comprise at least one of nanodiamond, carbon nanotubes, gold nanoparticles, graphene, and nanoclay.

5. The material coating system (200) according to claim 2, wherein the additive material (304) comprises micro-sized particles.

6. The material coating system (200) according to claim 2, wherein the additive material (304) comprises a mixture of nano-sized particles and micro-sized particles.

7. The material coating system (200) according to claim 1, wherein the topcoat layer (206) is a visually transparent varnish coating.

8. The material coating system (200) according to claim 1, further comprising: a reflective layer (208) deposited between the laser ablation layer (204) and the substrate (202) and configured to reflect the laser (106) of the specified wavelength.

9. The material coating system (200) according to claim 1, wherein the substrate (202) comprises a metal alloy.

10. The material coating system (200) according to claim 1, wherein the substrate (502) comprises a fiber layer (502') and a resin layer (502''), and wherein the resin layer (502'') is adapted to absorb the laser (508) of the specified wavelength such that application of the laser (508) of the specified wavelength to the resin layer (502'') causes the resin layer (502'') to delaminate from the fiber layer (502') of the substrate (502).

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