Method of producing magnesium-containing component having visual metal surface

Abstract

A method of coating magnesium includes applying a surface finishing to a magnesium substrate to obtain a surface finished magnesium substrate having a visual profile. The method includes pre-treating the surface finished magnesium substrate to obtain a pre-treated magnesium substrate. The method includes depositing a transparent powder coating onto the pretreated magnesium substrate to obtain a powder coated magnesium substrate. The powder coated magnesium substrate retains the visual profile of the surface finished magnesium substrate or as-cast magnesium.

Description

Background Art

[0001] Magnesium alloys have utility in a wide variety of applications, including, for example, automotive applications (e.g., vehicle panels, structural members, etc.) One very advantageous feature of using magnesium alloys in automotive applications is that such alloys offer high strength and good formability, and additionally can provide significant weight savings compared to more traditional steel components.

[0002] In certain vehicle applications, it may be desirable to have surfaces with a metallic appearance (so-called "Class A" surfaces) facing the passengers in the cabin for aesthetic or other reasons. Because metal components are not typically provided as bare metal surfaces to avoid negative effects such as oxidation, a surface treatment or coating may often be applied to the metal components. For example, when magnesium alloys are used to form metal components with Class A surfaces, one approach involves applying a powder coating to the magnesium substrate to approximate the appearance of metal. However, one disadvantage of this powder coating process is that once the powder coating is applied to the magnesium substrate, the underlying magnesium substrate is no longer visible. In other scenarios, a pre-treatment may be applied to the magnesium substrate, which may adversely cause discoloration of the appearance of the magnesium substrate.

[0003] It would be advantageous to provide a method for treating magnesium substrates to allow such substrates to retain their metallic visual appearance while addressing the challenges associated with having a metal surface exposed as a Class A visual surface. A surface finish can be applied to a magnesium substrate such that the appearance of the surface finished magnesium substrate will be visible after undergoing processing steps to obtain advantageous properties (e.g., mechanical properties, corrosion resistance, hardness, wear resistance, and cost). These and other advantageous features will become apparent to those reviewing this disclosure. Summary of the invention

[0004] Embodiments described herein generally relate to methods for treating (e.g., coating) a magnesium-containing substrate to provide a visual surface that maintains its metallic aesthetics. The coating of the magnesium-containing substrate can be free of undesirable coloration while having sufficient wear resistance to be classified as a Class A coating.

[0005] At least one aspect of the present disclosure relates to a method of coating magnesium. The method includes applying a surface finish to a magnesium substrate to obtain a surface-finished magnesium substrate having a visual profile. The method includes pre-treating the surface-finished magnesium substrate with a BASF Oxsilan 9831 process to obtain a pre-treated magnesium substrate. The method includes depositing a clear powder coating onto the pre-treated magnesium substrate to obtain a powder-coated magnesium substrate. The powder-coated magnesium substrate maintains the visual profile of the surface-finished magnesium substrate.

[0006] Another aspect of the present disclosure relates to a method of coating magnesium. The method includes applying a surface finish to a magnesium substrate to obtain a surface finished magnesium substrate having a visual profile. The method includes pretreating the magnesium substrate with a Henkel MgC process to obtain a pretreated magnesium substrate. The method includes depositing a clear powder coating onto the pretreated magnesium substrate to obtain a powder coated magnesium substrate. The powder coated magnesium substrate retains the visual profile of the surface finished magnesium substrate.

[0007] Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features and advantages of the devices and / or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The details of one or more embodiments of the subject matter described in this specification are set forth in the drawings and description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, drawings, and claims.

[0009] Figure 1 A vehicle cabin having one or more exposed Class A magnesium surface components is shown according to some embodiments.

[0010] Figure 2 As-cast magnesium substrates according to some embodiments and pre-treated magnesium substrates using conventional or existing processes are shown.

[0011] Figure 3 An as-cast magnesium substrate and a polished panel of the magnesium substrate are shown according to some embodiments.

[0012] Figure 4 A milled panel of a magnesium substrate according to some embodiments is shown.

[0013] Figure 5 Laser etching finishing of a magnesium substrate according to some embodiments is demonstrated.

[0014] Figure 6 Shown are ground and milled magnesium substrates that have undergone BASF's Oxsilan 9831 process according to some embodiments.

[0015] Figure 7 Demonstrating some embodiments Figure 6 A pre-treated magnesium substrate that has undergone a powder coating process.

[0016] Figure 8 Shown are ground and milled magnesium substrates that have undergone the Henkel MgC process according to some embodiments.

[0017] Fig. 9 Demonstrating some embodiments Figure 8 A pre-treated magnesium substrate that has undergone a powder coating process.

[0018] Fig.10 Methods of coating magnesium according to some embodiments are presented.

[0019] Fig.11 A graph showing surface roughness of a magnesium substrate relative to powder coating gloss level according to some embodiments is shown.

[0020] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0021] Various concepts and embodiments related to methods, apparatuses, and systems for coating magnesium, magnesium alloys, or magnesium-containing substrates to provide visual surfaces that maintain their metallic aesthetics are described in more detail below. The various concepts introduced above and discussed in more detail below can be implemented in any of many ways, as the concepts described are not limited to any particular manner of embodiment. Examples of specific embodiments and applications are provided primarily for illustrative purposes.

[0022] The present disclosure relates to methods for treating a magnesium substrate (e.g., a magnesium-containing substrate) or alloy to provide a visual surface that maintains its metallic aesthetics. Existing treatment processes for magnesium-containing substrates may have many problems, including but not limited to discoloration of the magnesium-containing substrate, concealment of underlying metal properties of the magnesium-containing substrate, and insufficient wear resistance. In addition, existing coating processes for magnesium-containing substrates may be susceptible to corrosion. Porosity in or on a coating of a magnesium-containing substrate may increase the risk of corrosion. Existing coating processes for other alloys (such as aluminum alloys or steel) may be ineffective or impractical for magnesium alloys. For example, a coating process for aluminum may include applying a coating containing an acid (e.g., sulfuric acid, nitric acid, phosphoric acid, etc.), which will rapidly dissolve the magnesium alloy without forming a protective layer. Although existing processes can be applied to magnesium-containing aluminum alloys, these aluminum alloys typically contain a small amount of magnesium (e.g., less than 3wt%). In contrast, a magnesium alloy may contain greater than 80wt% or 90wt% magnesium.

[0023] The methods of the present disclosure can address these and other issues associated with treating magnesium-containing substrates to provide a visual surface that maintains its metallic aesthetics while achieving sufficient wear resistance for the coating of the magnesium-containing substrate to be classified as a Class A coating. Additionally, the pretreatment process and powder coating process can provide a clear coating having a thickness of about 50-200 μm. Such a clear coating can be thick enough to provide wear resistance and physical protection to the underlying magnesium-containing substrate.

[0024] According to an exemplary embodiment, a method for coating magnesium, a magnesium alloy, or a magnesium substrate (e.g., a magnesium-containing substrate) is provided. The surface of the magnesium, magnesium alloy, or magnesium substrate may have the appearance of original magnesium or magnesium metal. The method may provide a visible surface without changing the color of the underlying magnesium, magnesium alloy, or magnesium substrate (e.g., a cast magnesium substrate, a cast magnesium alloy, etc.). The method of the present disclosure may overcome the limitations of existing production processes, which may cause magnesium to change color (e.g., turn yellow or green) or may not simulate cast magnesium in sufficient detail. For example, existing production processes may only be able to simulate 10% of cast magnesium, while the method of the present disclosure may simulate a higher percentage of cast magnesium, such as 95% of cast magnesium.

[0025] According to a specific exemplary embodiment, the method includes applying a surface finish to a magnesium substrate to obtain a surface-finished magnesium substrate having a visual profile, pre-treating the surface-finished magnesium substrate with BASF Oxsilan 9831 process to obtain a pre-treated magnesium substrate, and depositing a transparent powder coating onto the pre-treated magnesium substrate to obtain a powder-coated magnesium substrate. The powder-coated magnesium substrate maintains the visual profile of the surface-finished magnesium substrate or the cast magnesium substrate.

[0026] According to a specific exemplary embodiment, the method includes applying a surface finish to a magnesium substrate to obtain a surface-finished magnesium substrate having a visual profile, pre-treating the surface-finished magnesium substrate with a Henkel MgC process to obtain a pre-treated magnesium substrate, and depositing a transparent powder coating onto the pre-treated magnesium substrate to obtain a powder-coated magnesium substrate. The powder-coated magnesium substrate maintains the visual profile of the surface-finished magnesium substrate or the cast magnesium substrate.

[0027] The method of the present disclosure can allow for a clear coating system that includes surface preparation (e.g., sanding, orbital sanding, grinding, belt sanding, wire brushing, etc.), pretreatment, and powder coating. Surface preparation can be used to produce different textures, thereby producing different visual surfaces. The method can provide a Class A coating for magnesium alloys and magnesium substrates. The coating can be transparent and reveal (e.g., show) the underlying magnesium alloy or substrate. The coating can reveal the metallic appearance of the underlying magnesium alloy or substrate, rather than providing a non-transparent metallic surface finish. For example, the coating can be clear (clear / transparent), rather than a shiny metallic coating deposited onto the magnesium alloy or substrate.

[0028] Figure 1A vehicle cabin 100 is shown having one or more components formed of magnesium or a magnesium alloy and having a metallic aesthetic appearance (hereinafter referred to as "exposed magnesium" components for brevity). The exposed magnesium components may include, for example, one or more magnesium panels 105. The one or more magnesium panels 105 may include a magnesium substrate that has undergone a finishing process (e.g., a treatment process, a surface treatment process, a coating process, a surface coating process, etc.). For example, the finishing process may treat the magnesium substrate so that the magnesium substrate meets the performance and aesthetic standards of the interior metal components. For example, the exposed magnesium component or magnesium substrate may have desired chemical resistance, corrosion resistance, and adhesion.

[0029] The surface finishing (e.g., coating, surface coating, etc.) on the magnesium substrate can advantageously meet the General Motors Worldwide Engineering Standards Material Specification Finish GMW14669, which provides organic coating properties for exterior and interior metal materials. According to the GMW14669 specification, the surface finishing on the magnesium substrate can be classified as Class B1. The Class B1 classification can be suitable for surface finishes used on interior body parts and components in harsh service operating environments (e.g., sunlight, direct sunlight and corrosion, items in contact with wet floors, such as lower seat structures).

[0030] According to the adhesion requirements in General Motors Worldwide Engineering Standards Test Procedure GMW14829 (Tape Adhesion Test for Painted Finishes), the surface finish on the magnesium substrate may be rated 0 or 1. According to the post-humidity adhesion requirements in GMW14729 specification (Tape Adhesion Test for Painted Finishes), the surface finish on the magnesium substrate may be rated 0 or 1 for a duration of 144 hours. According to the humidity exposure test requirements in GMW14729 specification (High Humidity Test Procedure), the surface finish on the magnesium substrate may not undergo surface changes for a duration of 144 hours. According to the cyclic corrosion test requirements in General Motors Worldwide specification GMW14872 (Cyclic Corrosion), the surface finish on the magnesium substrate may be rated 10 and 3 mm for creep at the intermediate / high internal (INT) mounting position and for a duration of 7 cycles / 12 cycles. The surface finish on the magnesium substrate may have a minimum hardness of "H" according to the pencil hardness test requirements in specification ISO 15184 (Paints and varnishes - Determination of film hardness by pencil test). The surface finish on the magnesium substrate may be rated 0 or 1 according to the cure test requirements in General Motors Worldwide specification GMW15891 (Introduction to solvent rubbing method for determining cure of painted metal or plastic substrates). The surface finish on the magnesium substrate may be rated 2 according to the cleaning agent resistance requirements of Code A in General Motors Worldwide specification GMW14334 (Fluid Chemical Resistance). The surface finish on the magnesium substrate may be wear-free according to the wear resistance requirements in General Motors Worldwide specification GMW3208 (Rotary Wear Test) by using a CS10 wheel, 500g load and 1000 cycles.

[0031] Advantageously, the magnesium panel 105 can have a visual profile with the appearance of raw magnesium (e.g., a desired visual profile). For example, the magnesium panel 105 can have the appearance of magnesium metal, raw magnesium, or cast magnesium. According to an exemplary embodiment, the magnesium panel 105 is formed of a magnesium alloy (e.g., magnesium alloy AM60B, magnesium alloy AM50A, or magnesium alloy AZ91D) and can be used in various vehicle applications (e.g., as a backing for a vehicle infotainment center, as a cover for a vehicle infotainment center, as a decorative element, or for any other desired purpose).

[0032] Figure 2 A cast magnesium substrate 205 and a pre-treated magnesium substrate 210 are shown. The cast magnesium substrate 205 may include a cast magnesium alloy. The cast magnesium substrate 205 may be obtained directly from casting (e.g., by melting and solidification). The cast magnesium substrate 205 may include a magnesium substrate or a magnesium alloy that has not undergone any additional chemical or mechanical processing (e.g., machining, coating, finishing, chemical alteration, etc.) after the casting process. The magnesium alloy may include a mixture of magnesium with other metals (e.g., aluminum, zinc, manganese, silicon, copper, rare earths, zirconium, etc.). According to an exemplary embodiment, the magnesium alloy may include a percentage of magnesium, for example, 80wt% magnesium, 81wt% magnesium, 82wt% magnesium, 83wt% magnesium, 84wt% magnesium, 85wt% magnesium, 86wt% magnesium, 87wt% magnesium, 88wt% magnesium, 89wt% magnesium, 90wt% magnesium, 90.8wt% magnesium, 91wt% magnesium, 91.5wt% magnesium, 92wt% magnesium, 93wt% magnesium, 93.5wt% magnesium, 93.6wt% magnesium, 94wt% magnesium, 95wt% magnesium, 96wt% magnesium, 97wt% magnesium, 98wt% magnesium, 99wt% magnesium or 99.2wt% magnesium, with the remainder being one or more metals. The magnesium alloy may include a casting alloy (e.g., a casting magnesium alloy). For example, the magnesium alloy may include AZ63, AZ81, AZ91, AM50, AM60, ZK51, ZK61, ZE41, ZC63, HK31, HZ32, QE22, QH21, WE54, WE43, or Elektron21.

[0033] The cast magnesium substrate 205 may have the appearance of raw magnesium (e.g., elemental magnesium, natural magnesium, Mg, etc.). For example, the appearance of raw magnesium may include the visual appearance and / or characteristics of elemental magnesium. The cast magnesium substrate 205 may display the cast magnesium substrate 205 instead of the metallic appearance from the coating deposited on the cast magnesium substrate 205. The cast magnesium substrate 205 may have a metallic aesthetic appearance (e.g., a gray appearance, a shiny gray appearance, a silvery white appearance, an off-white appearance, a ceramic white appearance, or a ceramic gray appearance). The cast magnesium substrate 205 may have a luster or shine. The cast magnesium substrate 205 may have a shiny appearance instead of a dull appearance. For example, the cast magnesium substrate 205 may be shiny because it reflects light. The cast magnesium substrate 205 may have the appearance of a magnesium ore. For example, the cast magnesium substrate 205 may have the appearance of magnesite (MgCO3), dolomite (CaMg(CO3)2), or carnallite (KMgCl3.6(H2O)).

[0034] The pre-treated magnesium substrate 210 may include a magnesium substrate treated using conventional or existing processes. The pre-treated magnesium substrate 210 may include a magnesium substrate prior to powder coating the magnesium substrate. An example of such existing processes is Henkel 5200 treatment (e.g., Alodine treatment, Alodine process, chemical film treatment, chemical film process, etc.). Alodine treatment may include a non-chromate conversion coating that protects magnesium and other metals (e.g., aluminum) from corrosion. Alodine treatment may color or discolor the cast magnesium substrate 205. For example, Alodine treatment may include coating the cast magnesium substrate 205 with Alodine to obtain a pretreated magnesium substrate 210. The pretreated magnesium substrate 210 may include a cast magnesium substrate 205 having an Alodine coating. Alodine treatment may include coating the cast magnesium substrate 205 with Alodine and exposing the Alodine-coated substrate to heat. The Alodine-coated substrate may be exposed to a temperature greater than 200°C (e.g., 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 350°C, 400°C, 500°C, etc.). The pre-treated magnesium substrate 210 may include a heat treated Alodine coated substrate. Prior to the powder coating process, the as-cast magnesium substrate 205 may need to be exposed to temperatures greater than 200° C. for degassing.

[0035] Existing processes (e.g., Alodine treatment) may discolor the cast magnesium substrate 205. The organic components in Alodine may discolor the organic fluoride Zr / Ti based propoxy propanol conversion coating during degassing and heating. Prior to the degassing and heating process, these organic components may be transparent, allowing the magnesium substrate to maintain its metallic aesthetic appearance or the underlying metallic appearance. Although the cast magnesium substrate 205 is coated with Alodine, the coated magnesium substrate may have a metallic aesthetic appearance before the degassing and heating process. However, after the degassing and heating process, the organic components may discolor and cause the magnesium substrate to lose its metallic aesthetic appearance. The pretreated magnesium substrate 210 may include the cast magnesium substrate 205 after it has been coated with Alodine, degassed, and heated to a temperature greater than 200°C. The pretreated magnesium substrate 210 may have a light yellow and / or light green color.

[0036] The existing process may change the appearance of the cast magnesium substrate 205 so that the appearance of the pretreated magnesium substrate 210 has a light yellow or light green color. The appearance of the cast magnesium substrate 205 may be different from the appearance of the pretreated magnesium substrate 210. For example, the appearance of the cast magnesium substrate 205 may be different from the appearance of a magnesium substrate that has undergone an Alodine treatment. The appearance of the cast magnesium substrate 205 may be different from the appearance of a magnesium substrate coated with Alodine and heated to a temperature greater than 200° C. The existing process may also discolor other metal substrates, such as aluminum substrates or steel substrates. Cleaning chemicals, such as acetic acid, may not discolor the cast magnesium-based material 205.

[0037] Figure 3 As-cast magnesium substrate 205 and three polished panels of cast magnesium substrates are shown (substrate 310 polished with 40 grit paper, substrate 315 polished with 120 grit paper, and substrate 320 polished with 180 grit paper from left to right). The lower row provides magnified views of the panels in the top row (i.e., image 325 is a magnified view (scanning electron microscope (SEM) image) of substrate 205, image 330 is a magnified view (SEM image) of substrate 310, image 335 is a magnified view (SEM image) of substrate 315, and image 340 is a magnified view (SEM image) of substrate 320).

[0038] like Figure 3 As shown, the magnified image 325 of the as-cast magnesium substrate 205 exhibits surface non-uniformities, such as deviations from an average height of the surface (eg, surface height) and / or deviations from an average distance between local maxima of the surface.

[0039] Figure 3The 40 grit, 120 grit, and 180 grit polished panels of the magnesium substrate shown in show a magnesium substrate (e.g., cast magnesium substrate 205) that has undergone or has been subjected to a surface finishing step (e.g., orbital polishing, orbital buffing, etc.). The resulting magnesium substrate (e.g., a magnesium substrate that has undergone or has been subjected to a surface finishing step) has various surface textures corresponding to the grit of the polishing (e.g., alumina) paper, with the 180 grit panels having an overall "smoother" surface texture than the 40 grit or 120 grit panels. The polishing process may be performed prior to pretreatment of the magnesium substrate. The resulting magnesium substrate may be referred to as a surface finished magnesium substrate. The Ra (e.g., arithmetic mean roughness, surface roughness) of a typical cast magnesium may be 0.9 ± 0.2. The Ra of cast magnesium (including powder coating) may be 1.23 ± 0.2. The Ra of a magnesium substrate polished with 40 grit paper may be 1.9 ± 0.4. The Ra of a magnesium substrate polished with 120 grit paper may be 1.65 ± 0.2. The Ra of a magnesium substrate polished with 180 grit paper may be 1.35 ± 0.2.

[0040] Figure 4 A grinding panel of a magnesium substrate is shown. The grinding panel of the magnesium substrate may include a magnesium substrate that has undergone or has been subjected to a surface finishing step (e.g., belt grinding, wire brushing, etc.). The resulting magnesium substrate (e.g., a magnesium substrate that has undergone or has been subjected to a surface finishing step) may have various surface textures corresponding to the particle size of the abrasive belt. The magnesium substrate may undergo wire brush grinding finishing. A wire brushed (e.g., brushed) magnesium substrate may produce a brushed magnesium substrate. Grinding may be a mechanical finishing step performed before or before pretreatment of the magnesium substrate. Belt grinding may be a mechanical finishing step performed before or before pretreatment of the magnesium substrate. Wire brushing may be a mechanical finishing step performed before or before pretreatment of the magnesium substrate. The resulting magnesium substrate may be referred to as a surface finished magnesium substrate.

[0041] The panels of the magnesium substrate grind from left to right include substrate 405 grinded with a 40 grit belt, substrate 410 grinded with a 60 grit belt, and substrate 415 grinded with an 80 grit belt. The lower row provides magnified views of the panels in the top row (i.e., image 420 is a magnified view (SEM image) of substrate 405, image 425 is a magnified view (SEM image) of substrate 410, and image 430 is a magnified view (SEM image) of substrate 415). The as-cast magnesium substrate 205 may be subjected to belt grinding or wire brushing.

[0042] Figure 4The 40 grit, 60 grit, and 80 grit milled panels of the magnesium substrate shown in show a magnesium substrate (e.g., cast magnesium substrate 205) that has undergone or been subjected to a surface finishing step (e.g., belt sanding, wire brushing, grinding, etc.). The resulting magnesium substrate (e.g., a magnesium substrate that has undergone or been subjected to a surface finishing step) has various surface textures corresponding to the grit of the grinding (e.g., aluminum oxide) paper, with the 80 grit panel having an overall "smoother" surface texture than the 40 grit or 60 grit panels. The grinding process can be performed prior to pretreatment of the magnesium substrate. The resulting magnesium substrate can be referred to as a surface finished magnesium substrate. The Ra of the magnesium substrate milled with 40 grit paper measured perpendicular to the grind can be 3±0.4. The Ra of the magnesium substrate milled with 40 grit paper measured parallel to the grind can be 1.0±0.15. The Ra of the magnesium substrate milled with 60 grit paper measured perpendicular to the grind can be 1.5±0.2. The Ra of the magnesium substrate ground with 60 grit paper measured parallel to the grind can be 0.75 ± 0.15. The Ra of the magnesium substrate ground with 80 grit paper measured perpendicular to the grind can be 1.4 ± 0.15. The Ra of the magnesium substrate ground with 80 grit paper measured parallel to the grind can be 0.5 ± 0.15.

[0043] Figure 5 Laser etching finishing of a magnesium substrate is shown. The cast magnesium substrate 205 may undergo or be subjected to a surface finishing step including laser etching. The laser etching process may produce a magnesium substrate having different surface textures. The magnesium substrate may undergo cleaning and etching with different process parameters. The magnesium substrate may include a cleaned magnesium substrate 505. The cleaned magnesium substrate 505 may be laser etched with a 160 mm lens. The magnesium substrate may include a passivated magnesium substrate 510. The passivated magnesium substrate 510 may be laser etched with a 100 mm lens. Laser etching may be a mechanical finishing step performed before or prior to pretreatment of the magnesium substrate. The P4 parameters may use a 29.33 square centimeter / second removal rate and a 160 mm lens. The P4 parameters may produce a magnesium substrate having an Ra of 0.286 micrometers in 5 seconds. The P9 parameters may use a 17.6 square centimeter / second removal rate and a 100 mm lens. The P9 parameters may produce a magnesium substrate having an Ra of 0.992 micrometers in 9 seconds.

[0044] Figure 6A polished and ground magnesium substrate that has undergone a pre-treatment process, such as a BASF Oxsilan 9831 process (e.g., a BASF Oxsilan 9831 treatment process, etc.) is shown. The first magnesium substrate 605 may include a magnesium substrate (e.g., an AM60B magnesium substrate) that has undergone polishing (e.g., orbital polishing) and a BASF Oxsilan 9831 process. The first magnesium substrate 605 may include a magnesium substrate that has undergone a BASF Oxsilan 9831 process. The BASF Oxsilan 9831 process may be performed after the orbital polishing process. The first magnesium substrate 605 may include, for example, a 40-grit polished magnesium substrate 310, a 120-grit polished magnesium substrate 315, a 180-grit polished magnesium substrate 320, or any other polished magnesium substrate. The top image of the first magnesium substrate 605 shows a first side of the first magnesium substrate 605. The bottom image of the first magnesium substrate 605 shows a second (e.g., opposite) side of the first magnesium substrate 605. Compared to magnesium substrates that have been discolored by other pretreatment processes, the BASF Oxsilan 9831 process can produce a magnesium substrate having the visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The BASF Oxsilan 9831 process can produce a pretreated magnesium substrate (e.g., the first magnesium substrate 605) that retains the metallic aesthetics of cast magnesium. The BASF Oxsilan 9831 process can reduce the roughness of the magnesium substrate. The Ra of the first magnesium substrate 605 polished with 40 grit paper can be 0.9±0.2.

[0045] The second magnesium substrate 610 may include a magnesium substrate (e.g., AM60B magnesium substrate) that has undergone grinding (e.g., belt sanding, wire brushing, etc.) and BASF Oxsilan 9831 process. The second magnesium substrate 610 may include a magnesium substrate that has undergone BASF Oxsilan 9831 process. The BASF Oxsilan 9831 process may be performed after the belt sanding or wire brushing process. The second magnesium substrate 610 may include, for example, a 40-grit ... The BASF Oxsilan 9831 process can produce a pretreated magnesium substrate (e.g., the second magnesium substrate 610) that retains the metal aesthetics of cast magnesium. The BASF Oxsilan 9831 process can reduce the roughness of the magnesium substrate. The Ra of the second magnesium substrate 610 measured perpendicular to the grind, ground with 40 grit paper, can be 2.75 ± 0.6. The Ra of the second magnesium substrate 610 measured parallel to the grind, ground with 40 grit paper, can be 0.99 ± 0.3.

[0046] Figure 7 Shown Figure 6A pretreated magnesium substrate that has undergone a powder coating process. The first powder-coated magnesium substrate 705 may include the first magnesium substrate 605 that has been powder coated. The first powder-coated magnesium substrate 705 may include a magnesium substrate that has undergone a powder coating process. The first powder-coated magnesium substrate 705 may include a magnesium substrate that has undergone a BASF Oxsilan 9831 process. The BASF Oxsilan 9831 process may be a pretreatment process applied before the powder coating process. The first powder-coated magnesium substrate 705 may include a magnesium substrate that has undergone a polishing process. The first powder-coated magnesium substrate 705 may include the first magnesium substrate 605 after undergoing a powder coating process. The powder coating process may include applying a powder coating (e.g., a clear powder coating, a low gloss powder coating, etc.) to the first magnesium substrate 605. Compared to a magnesium substrate that has been discolored by other pretreatment processes, the powder coating process may produce a magnesium substrate having a visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The powder coating process can produce a powder coated magnesium substrate (e.g., first powder coated magnesium substrate 705) that retains the metallic aesthetics of cast magnesium. The surface roughness of the first powder coated magnesium substrate 705 can be dominated by the roughness produced by the powder coating process. The Ra of the first powder coated magnesium substrate 705 polished with 40 grit paper can be 1.22±0.17.

[0047] The second powder-coated magnesium substrate 710 may include a second magnesium substrate 610 that has been powder-coated. The second powder-coated magnesium substrate 710 may include a second magnesium substrate 610 that has undergone a powder coating process. The second powder-coated magnesium substrate 710 may include a magnesium substrate that has undergone a BASF Oxsilan 9831 process. The BASF Oxsilan 9831 process may be a pretreatment process applied before the powder coating process. The first powder-coated magnesium substrate 705 may include a magnesium substrate that has undergone grinding. The powder coating process may include applying a powder coating (e.g., a clear powder coating, a low gloss powder coating, etc.) to the second magnesium substrate 610. Compared to a magnesium substrate that has been discolored by other pretreatment processes, the powder coating process may produce a magnesium substrate having a visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The powder coating process may produce a powder-coated magnesium substrate (e.g., the second powder-coated magnesium substrate 710) that maintains the metallic aesthetics of cast magnesium. The surface roughness of the second powder-coated magnesium substrate 710 may be dominated by the roughness produced by the powder coating process. The second powder coated magnesium substrate 710 ground with 40 grit paper may have an Ra of 1.33 ± 0.17 measured perpendicular to the grind. The second powder coated magnesium substrate 710 ground with 40 grit paper may have an Ra of 1.36 ± 0.22 measured parallel to the grind.

[0048] Figure 8A polished and ground magnesium substrate that has undergone a pretreatment process, such as a Henkel MgC process (e.g., a Henkel MgC treatment process) is shown. The third magnesium substrate 805 may include a magnesium substrate (e.g., an AM60B magnesium substrate) that has undergone polishing (e.g., orbital polishing) and a Henkel MgC process. The third magnesium substrate 805 may include a magnesium substrate that has undergone a Henkel MgC process. The Henkel MgC process may be performed after the orbital polishing process. The third magnesium substrate 805 may include, for example, a 40-grit polished magnesium substrate 310, a 120-grit polished magnesium substrate 315, a 180-grit polished magnesium substrate 320, or any other polished magnesium substrate. The top image of the third magnesium substrate 805 shows a first side of the third magnesium substrate 805. The bottom image of the third magnesium substrate 805 shows a second (e.g., opposite) side of the third magnesium substrate 805. Compared to magnesium substrates that have been discolored by other pretreatment processes, the Henkel MgC process can produce a magnesium substrate having a visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The Henkel MgC process can produce a pretreated magnesium substrate (e.g., the third magnesium substrate 805) that retains the metal aesthetics of cast magnesium. The Henkel MgC process can reduce the roughness of the magnesium substrate. The Ra of the third magnesium substrate 805 polished with 40 grit paper can be 1.1±0.4.

[0049] The fourth magnesium substrate 810 may include a magnesium substrate (e.g., AM60B magnesium substrate) that has undergone grinding (e.g., belt sanding, wire brushing, etc.) and a Henkel MgC process. The fourth magnesium substrate 810 may include a magnesium substrate that has undergone a Henkel MgC process. The Henkel MgC process may be performed after the belt sanding or wire brushing process. The fourth magnesium substrate 810 may include, for example, a 40-grit ... The Henkel MgC process can produce a pretreated magnesium substrate (e.g., a fourth magnesium substrate 810) that retains the metal aesthetics of cast magnesium. The Henkel MgC process can reduce the roughness of the magnesium substrate. The fourth magnesium substrate 810 ground with 40 grit paper can have an Ra measured perpendicular to the grind of 2.6 ± 0.4. The fourth magnesium substrate 810 ground with 40 grit paper can have an Ra measured parallel to the grind of 0.55 ± 0.1.

[0050] Fig. 9 Shown Figure 8The third powder-coated magnesium substrate 905 may include the third magnesium substrate 805 that has been powder-coated. The third powder-coated magnesium substrate 905 may include the third magnesium substrate 805 after having undergone the powder coating process. The third powder-coated magnesium substrate 905 may include a magnesium substrate that has undergone the Henkel MgC process. The MgC process may be a pretreatment process applied before the powder coating process. The third powder-coated magnesium substrate 905 may include a magnesium substrate that has undergone polishing. The powder coating process may include applying a powder coating (e.g., a clear powder coating, a low gloss powder coating, etc.) to the third magnesium substrate 805. Compared to a magnesium substrate that has been discolored by other pretreatment processes, the powder coating process may produce a magnesium substrate having a visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The powder coating process may produce a powder-coated magnesium substrate (e.g., the third powder-coated magnesium substrate 905) that maintains the metallic aesthetics of cast magnesium. The surface roughness of the third powder-coated magnesium substrate 905 may be dominated by the roughness produced by the powder coating process. The Ra of the third powder-coated magnesium substrate 905 polished with 40 grit paper may be 1.27±0.15.

[0051] The fourth powder-coated magnesium substrate 910 may include the fourth magnesium substrate 810 that has been powder-coated. The fourth powder-coated magnesium substrate 910 may include the fourth magnesium substrate 810 after undergoing the powder coating process. The fourth powder-coated magnesium substrate 910 may include a magnesium substrate that has undergone the Henkel MgC process. The MgC process may be a pretreatment process applied before the powder coating process. The fourth powder-coated magnesium substrate 910 may include a magnesium substrate that has undergone grinding. The powder coating process may include applying a powder coating (e.g., a clear powder coating, a low gloss powder coating, etc.) to the fourth magnesium substrate 810. Compared to a magnesium substrate that has been discolored by other pretreatment processes, the powder coating process may produce a magnesium substrate having a visual profile of a surface-finished magnesium substrate or a cast magnesium substrate. The powder coating process may produce a powder-coated magnesium substrate (e.g., the fourth powder-coated magnesium substrate 910) that maintains the metal aesthetics of cast magnesium. The surface roughness of the fourth powder-coated magnesium substrate 910 may be dominated by the roughness produced by the powder coating process. The fourth powder-coated magnesium substrate 910 ground with 40 grit paper may have an Ra of 1.3 ± 0.2 measured perpendicular to the grind. The fourth powder-coated magnesium substrate 910 ground with 40 grit paper may have an Ra of 1.27 ± 0.2 measured parallel to the grind.

[0052] Fig.10A method of coating magnesium is shown 1000. Briefly, method 1000 includes applying a surface finish to a magnesium substrate in step 1005, pretreating the surface finished magnesium substrate in step 1010, and depositing a clear powder coating onto the pretreated magnesium substrate in step 1015.

[0053] Additional details of the processing method 1000 are now provided. In step 1005, a surface finishing process is applied to the magnesium substrate to obtain a surface finished magnesium substrate having a visual profile that advantageously maintains the visual appearance of the underlying magnesium substrate (e.g., original magnesium). Any of a variety of alloys can be used to form the magnesium substrate, such as but not limited to magnesium alloy AM60B, magnesium alloy AM50A, or magnesium alloy AZ91D. During the surface finishing step, orbital sanding, belt sanding, wire brushing, and / or laser etching processes can be employed, depending on the desired aesthetics. As described above, each of these processes can be varied to obtain the desired surface finishing appearance.

[0054] In step 1010, the surface-finished magnesium substrate undergoes a pretreatment step. The pretreatment step may include treating the surface-finished magnesium substrate with the BASF Oxsilan 9831 process to obtain a pretreated magnesium substrate (e.g., a pretreated magnesium-containing substrate). The BASF Oxsilan 9831 process may include a multi-purpose liquid pretreatment. The BASF Oxsilan 9831 process does not discolor the surface-finished magnesium substrate. The BASF Oxsilan 9831 process may include alkaline cleaning of the magnesium substrate with a cleaner (e.g., TP10367) to remove oil, lubricants, debris, or any contaminants, etc. The BASF Oxsilan 9831 process may include rinsing the magnesium substrate twice with water (e.g., city water, tap water, etc.). The BASF Oxsilan 9831 process may include deoxidizing the magnesium substrate with Gardacid P4462 / 1 to remove the oxide layer on the magnesium substrate. The BASF Oxsilan 9831 process may include rinsing the magnesium substrate twice with water (e.g., deionized water, reverse osmosis water, etc.). The BASF Oxsilan 9831 process may include applying Oxsilan 9831 (e.g., a silane-based, multi-purpose, liquid pretreatment) to the magnesium substrate. The BASF Oxsilan 9831 process may include rinsing the magnesium substrate twice with water (e.g., deionized water, reverse osmosis water, etc.) after applying Oxsilan 9831 to the magnesium substrate. The BASF Oxsilan 9831 process may include degassing and drying the magnesium substrate.

[0055] According to another exemplary embodiment, step 1010 may alternatively employ the Henkel MgC process to obtain a pretreated magnesium substrate (e.g., a pretreated magnesium-containing substrate) that produces a magnesium oxide surface layer having a thickness of 2 μm to 4 μm on the magnesium substrate. The Henkel MgC process may include a plasma electrolytic ceramic deposition process. The Henkel MgC process may give the surface-finished magnesium substrate a white appearance. The visual appearance of the pretreated magnesium substrate may be the same as the visual appearance of the surface-finished magnesium substrate, the original magnesium, or the cast magnesium substrate. The Henkel MgC process may include alkaline cleaning of the magnesium substrate with a cleaning agent (e.g., Bonderite C-IC6849). The Henkel MgC process may include rinsing the magnesium substrate twice with water (e.g., city water, tap water, etc.). The Henkel MgC process may include deoxidizing the magnesium substrate with Bonderite C-IC 8242 to remove the oxide layer on the magnesium substrate. The Henkel MgC process may include rinsing the magnesium substrate twice with water (e.g., deionized water, reverse osmosis water, etc.). The Henkel MgC process may include applying MgC to a magnesium substrate. The Henkel MgC process may include, after applying MgC to the magnesium substrate, rinsing the magnesium substrate twice with water (e.g., deionized water, reverse osmosis water, etc.). The Henkel MgC process may include drying the magnesium substrate.

[0056] In step 1015, a transparent powder coating is deposited onto the pretreated magnesium substrate to obtain a powder-coated magnesium substrate (e.g., a powder-coated magnesium-containing substrate). The powder-coated magnesium substrate can maintain the visual profile of the surface-finished magnesium substrate or the cast magnesium substrate. The transparent powder coating can include a low-gloss powder coating. The transparent powder coating can prevent oxidation and thus provide a certain level of corrosion resistance, and can also provide a certain level of UV resistance. The low-gloss powder coating can provide a transparent finish with minimal pinholes or pores. For example, the density of pinholes and / or pores can make the powder-coated magnesium substrate less susceptible to corrosion. The visual appearance of the powder-coated magnesium substrate can be the same as the visual appearance of the surface-finished magnesium substrate, the original magnesium, or the cast magnesium substrate.

[0057] Fig.11 A graph showing the surface roughness of a magnesium substrate relative to the gloss level of a powder coating. Surface roughness Ra can be measured in microns. Gloss levels between 4 and 12 may produce a magnesium substrate where the powder coating is less visually noticeable on the surface due to high gloss or high texture. Surface roughness between 0.93 and 1.53 microns may produce a magnesium substrate with a surface roughness similar to that of as-cast magnesium.

[0058] Any reference to the embodiment or element or action of system and method quoted in singular form herein can cover the embodiment including multiple these elements, and any reference to any embodiment or element or action in plural form herein can cover the embodiment including only single element. Reference in singular or plural form is not intended to limit the currently disclosed system or method, its components, actions or elements to single or multiple configurations. Reference to any action or element based on any information, action or element can include an embodiment in which the action or element is at least partially based on any information, action or element.

[0059] Any embodiment disclosed herein may be combined with any other embodiment, and references to "an embodiment," "some embodiments," "an alternative embodiment," "various embodiments," "an embodiment," etc. are not necessarily mutually exclusive, and are intended to indicate that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Such terms as used herein do not necessarily all refer to the same embodiment. Any embodiment may be combined, inclusively or exclusively, with any other embodiment in any manner consistent with the aspects and embodiments disclosed herein.

[0060] References to "or" may be interpreted as inclusive, such that any term described using "or" may indicate any of a single, more than one, and all of the terms described. References to at least one of a conjunction list of terms may be interpreted as inclusive or indicate any of a single, more than one, and all of the terms described. For example, references to "at least one of 'A' and 'B'" may include only 'A', only 'B', and both 'A' and 'B'. Elements other than 'A' and 'B' may also be included.

[0061] All disclosed ranges should be understood to cover and support claims for any and all sub-ranges or any and all individual values ​​contained in each range. For example, the stated range of 1 to 10 should be deemed to include and support claims for any and all sub-ranges or individual values ​​between a minimum value of 1 and a maximum value of 10 and / or including the minimum value and the maximum value; that is, all sub-ranges start with a minimum value of 1 or greater, and end with a maximum value of 10 or less (e.g., 5.5 to 10, 2.34 to 3.56, etc.) or any value from 1 to 10 (e.g., 3, 5.8, 9.9994, etc.). Any listed range can be easily considered to fully describe and enable the same range to be decomposed into at least two, three, four, five, ten, etc., equal parts. As a non-limiting example, each range discussed herein can be easily decomposed into a lower third, a middle third, and an upper third, etc. As will also be understood by those skilled in the art, all language such as "at most," "at least," "greater than," "less than," etc. includes the listed numbers and refers to ranges that can then be broken down into sub-ranges as discussed above. Finally, as will be understood by those skilled in the art, ranges include each individual member. Thus, for example, a group having 1-3 layers refers to groups having 1, 2, or 3 layers. Similarly, a group having 1-5 layers refers to groups having 1, 2, 3, 4, or 5 layers, and so forth.

[0062] The drawings should be interpreted as showing one or more embodiments drawn to scale and / or one or more embodiments not drawn to scale. This means that the drawings may be interpreted as showing, for example, (a) everything drawn to scale, (b) nothing drawn to scale, or (c) one or more features drawn to scale and one or more features not drawn to scale. Thus, the drawings may be used to provide support for describing the size, proportions, and / or other dimensions of any of the features shown individually or relative to each other. Furthermore, all such sizes, proportions, and / or other dimensions should be understood to vary from 0% to 100% in either direction and, therefore, provide support for claims reciting such values ​​or any and all ranges or sub-ranges that may be formed from such values.

[0063] Unless expressly stated otherwise, all specified embodiments, features, and terms are intended to include the stated embodiment, feature, or term and its biological equivalents.

[0064] All patents, patent applications, provisional applications, and publications mentioned or cited herein are hereby incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

[0065] As used herein, "about" will be understood by one of ordinary skill in the art and will vary to some extent depending on the context in which it is used. If there is a use of a term that is unclear to one of ordinary skill in the art, "about" will mean up to plus or minus 10% of the particular term, taking into account the context in which the term is used.

[0066] The systems and methods described herein may be embodied in other specific forms without departing from their characteristics.The foregoing embodiments are illustrative rather than limiting of the described systems and methods.

[0067] Where a technical feature in the drawings, detailed description or any claims is followed by a reference numeral, the reference numeral has been included to increase the intelligibility of the drawings, detailed description and claims. Therefore, the presence or absence of a reference numeral has no limiting effect on the scope of any element of the claims.

[0068] The systems and methods described herein may be embodied in other specific forms without departing from their characteristics. The foregoing embodiments are illustrative rather than limiting of the described systems and methods. Therefore, the scope of the systems and methods described herein is indicated by the appended claims rather than the foregoing description, and changes within the meaning and scope equivalent to the claims are included therein.

Claims

1. A method for treating a substrate comprising magnesium or a magnesium alloy, the method comprising: applying a surface finishing treatment to a substrate comprising magnesium or a magnesium alloy so as to obtain a surface finished substrate having a visual profile; Pre-treating the surface-finished magnesium substrate using BASF Oxsilan 9831 process to obtain a pre-treated substrate; as well as depositing a clear powder coating onto the pretreated substrate to obtain a powder-coated substrate; wherein the powder coated magnesium substrate maintains the visual profile of the surface finished substrate. 2 . The method of claim 1 , wherein the substrate comprises magnesium alloy AM60B. The method of claim 1 , wherein the substrate comprises magnesium alloy AM50A. The method of claim 1 , wherein the substrate comprises magnesium alloy AZ91D.

5. The method of claim 1, wherein surface finishing comprises orbital grinding. The method of claim 1 , wherein the surface finishing comprises belt sanding. The method of claim 1 , wherein the surface finishing comprises grinding. The method of claim 1 , wherein the surface finishing comprises laser etching.

9. The method of claim 1, wherein the clear powder coating comprises a low gloss powder coating.

10. The method according to claim 1, wherein the transparent powder coating has a thickness of 50-200 μm.

11. A method of coating a magnesium-containing substrate, the method comprising: applying a surface finishing to a magnesium-containing substrate to obtain a surface-finished magnesium substrate having a visual profile; pretreating the magnesium substrate using a Henkel MgC process to obtain a pretreated magnesium-containing substrate; as well as depositing a clear powder coating onto the pretreated magnesium-containing substrate to obtain a powder-coated magnesium-containing substrate; wherein the powder coated magnesium-containing substrate maintains the visual profile of the surface-finished magnesium-containing substrate.

12. The method of claim 11, wherein the magnesium-containing substrate comprises magnesium alloy AM60B.

13. The method of claim 11, wherein the magnesium-containing substrate comprises magnesium alloy AM50A.

14. The method of claim 11, wherein the magnesium-containing substrate comprises magnesium alloy AZ91D.

15. The method of claim 11, wherein the surface finishing comprises orbital sanding.

16. The method of claim 11, wherein the surface finishing comprises belt sanding.

17. The method of claim 11, wherein the surface finishing comprises grinding.

18. The method of claim 11, wherein the surface finishing comprises laser etching.

19. The method of claim 11, wherein the clear powder coating comprises a low gloss powder coating.

20. The method according to claim 11, wherein the transparent powder coating has a thickness of 50-200 μm.

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