One way to lighten structures with little impact to stiffness and strength is to create a composite with thin metal walls and a light polymer core in between. Thin-walled composite formed enclosures may be used for automobile and aircraft parts, computing devices, and many other lightweight products. Strong and lightweight planar enclosures may be formed using laminated composite materials. However, some laminated composite materials cannot be deformed into non-planar three-dimensional forms.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.
Examples are disclosed that relate to composites and methods for forming non-planar composites. In one example, a method comprises providing a first non-planar metallic skin and a second non-planar metallic skin, providing a substantially planar core between the first non-planar metallic skin and the second non-planar metallic skin, and using the first non-planar metallic skin and the second non-planar metallic skin (1) to deform the core between the first non-planar metallic skin and the second non-planar metallic skin and (2) to bond the core to one or more of the first non-planar metallic skin and the second non-planar metallic skin.
A variety of products and components utilize enclosures that are desirably strong and stiff while also being lightweight. Examples include, but are not limited to, computing devices, parts for automobiles, aircraft, spacecraft, and the like. In some examples, such enclosures may have complex, three-dimensional shapes that create challenges in achieving the desired material properties while also being lightweight and enabling acceptable manufacturability.
In some structures, an outer surface of the structure may provide most of the stiffness and strength of the structure, while the core of the structure may primarily add weight and contribute less to the strength and stiffness. Lighter structures may be formed by removing portions of the solid material core. However, such processes can be labor-intensive and ill-suited for high volume, low cost manufacturing.
For example, hollow structural members take advantage of the strength and stiffness of the outer surface of the structure while a hollow core reduces weight. However, once manufactured hollow structural members generally cannot be formed into non-planar shapes, such as by thermoforming.
In other examples, a core of a lightweight material and strong outer skins may be laminated into a planar composite. For example, two flat metal sheets may be laminated to a polymer core to form a laminated planar composite sheet. However, such planar laminated composites lack sufficient structural integrity to allow the composite to be formed into complex shapes, such as non-planar three-dimensional forms. For example, thermoforming the laminated composite sheet described above may cause the polymer core to collapse, squeezing the polymer out of the perimeter of the composite sheet.
Accordingly, examples are disclosed that relate to composites and methods for forming non-planar composites that address one or more of the preceding issues. With reference now to
In the example schematically illustrated in
In another example schematically illustrated in
In this example, the second non-planar metallic skin 108 has substantially the same shape as the first non-planar metallic skin 104. For example, in
In the present example, as described in more detail below and with brief reference to
Accordingly, and in one potential advantage of the present disclosure, in some examples the methods disclosed herein may form non-planar composites having adjacent faces that form angles of at least 15 degrees with one another. While the disclosed example describes a 45 degree angle between faces, composites having many different angles, curvatures, and a variety of different shapes also may be formed using the disclosed methods and techniques.
Additionally, it will be appreciated that this example and the other examples of non-planar shapes shown and described in this disclosure are provided for clarity of description and for illustrative purposes. In other examples, a wide variety of non-planar shapes, including but not limited to shapes with fewer or more angled surfaces, curved surfaces, and symmetrical and asymmetrical aspects, may be utilized for the non-planar metallic skins and to form composites of the present disclosure.
With reference again to
In other examples, one or more features may be pre-formed in the first non-planar metallic skin and/or the second non-planar metallic skin. In some examples, the one or more features may be pre-formed in either the first non-planar metallic skin or the second non-planar metallic skin. In one example illustrated schematically in
In some examples, the first non-planar metallic skin 408 and a second non-planar metallic skin 412 may comprise machined parts. For example, the first non-planar metallic skin 408 and the second non-planar metallic skin 412 may be machined parts of an enclosure for a computing device.
In the examples described above, the first non-planar metallic skin and the second non-planar metallic skin may be pre-formed. Pre-forming the first non-planar metallic skin and the second non-planar metallic skin may be accomplished using standard stamping technology or any other suitable method. For example, sheet metal, which may comprise aluminum, stainless steel, copper or any other suitable metal, may be formed into a desired shape.
In some examples, the first non-planar metallic skin and the second non-planar metallic skin may comprise different materials. For example, where one of the skins is intended to face an interior portion of an enclosure for a computing device, such skin may be formed from copper to encourage heat conduction away from components of the computing device. In this example, the other skin may be intended to function as the outside of the enclosure. Accordingly, this skin may be machined from stainless steel to provide the structure with durability. In another example, an exterior-facing metallic skin may be stainless steel while the other skin intended to face the inside of the structure may be formed from a lighter-weight aluminum and/or magnesium alloy.
In a similar manner, a variety of materials may be utilized for the core 112. For example, the core 112 may comprise a polymer material, such as polyethylene, acrylonitrile butadiene styrene (ABS), polycarbonate, polypropylene, polysulfone or any other suitable material. In some examples the core may comprise a polymer film. In other examples, the core 112 may comprise a material such as an insulator or dielectric to provide the composite with desirable electrical properties. In some examples, the core 112 may have sufficient structural integrity without additional reinforcements, such as impregnated metal fibers.
In various examples, different thicknesses for the core 112 may be utilized. In some examples, a thickness for the core 112 may be selected based on one or more other parameters of the laminate composite and/or the intended use of the composite. In some examples, a core thickness of approximately 0.5 mm may be utilized. In some examples, utilizing a core thickness less than approximately 0.5 mm may negate the weight savings as compared to a solid structure of the same shape and materials. In other examples, such as forming a composite for an aircraft wing, significantly thicker cores may be utilized. In these examples, composites of the present disclosure may be formed having core thicknesses as great as approximately 0.5 m.
In another example, the first non-planar metallic skin and the second non-planar metallic skin may be formed from aluminum having a 0.1 mm thickness, and the core may comprise a polymer having a uniform 0.4 mm thickness. In this example, the thickness of the two layers of metallic skin and the core result in a composite having a 0.6 mm thickness. The 0.6 mm thick composite may be nearly as stiff and as strong as a 0.6 mm thick solid aluminum plate. Additionally, an approximately 40% weight reduction may be attained by utilizing the polymer core.
With reference now to
Deforming the core 112 may additionally include thermoforming the core. In some examples, when using the first non-planar metallic skin 104 and the second non-planar metallic skin 108 to thermoform the core 112, the punch 504 may comprise a heated punch, the die 508 may comprise a heated die, and the core 112 may comprise a thermoplastic polymer. In other examples, thermoforming the core 112 may comprise heating the core prior to deforming the core between the first non-planar metallic skin 104 and the second non-planar metallic skin 108. In yet other examples, the core 112 may be preheated, and then deformed using the first non-planar metallic skin 104 and the second non-planar metallic skin 108 with a non-heated punch and die.
In addition to deforming the core 112, the first non-planar metallic skin 104 and the second non-planar metallic skin 108 are used to bond the core to one or more of the skins, as described above. In some examples, an adhesive may be applied to one or more of the first non-planar metallic skin and the second non-planar metallic skin. As schematically illustrated in
In the above examples, the adhesives 704 and 804 may comprise an adhesive film, a primer, or a spray glue applied before the forming process to bond the core 112 to one or more of the metal skins. For example, the adhesive may comprise a film that is preapplied to one or both sides of the core 112, or provided as a separate sheet or film and formed onto the core 112. In various examples the adhesive may comprise an acrylic, silicone or urethane material, or any other suitable material to bond the core 112 to one or more of the metal skins.
In some examples, the core 112 may comprise an adhesive material or embody adhesive properties. For example, the core 112 may comprise a thermosetting polymer. In these examples, the core may bond well to one or more of the metal skins in the forming operation.
In the examples described above, setting or bonding the core 112 to one or more of the first non-planar metallic skin 104 and the second non-planar metallic skin 108 may be combined with deforming the core between the skins in a single compressive forming operation, press or step. Carrying out these processes in a single step may minimize the space and capital investment demands of production machinery, while also improving standardization and consistency in forming and bonding the composite.
Once the forming and bonding steps are complete, the composite may be blanked out and subjected to additional trimming or cleaning steps to form a final product. For example,
With reference to
At 1116, the method 1100 may include forming a feature comprising one or more of a rib, boss, and hole in the first non-planar metallic skin or the second non-planar metallic skin. At 1120, the method 1100 may include wherein the first non-planar metallic skin and the second non-planar metallic skin comprise different materials. At 1124, the method 1100 may include wherein the first non-planar metallic skin has a shape defining a four-sided open top enclosure, and the second non-planar metallic skin has substantially the shape of the first non-planar metallic skin.
At 1128, the method 1100 may include providing a substantially planar core between the first non-planar metallic skin and the second non-planar metallic skin. At 1132, the method 1100 may include wherein the core comprises a thermosetting polymer.
At 1136, the method 1100 may include applying an adhesive to one or more of the first non-planar metallic skin and the second non-planar metallic skin prior to using the first non-planar metallic skin and the second non-planar metallic skin to deform and bond the core. At 1140, the method 1100 may include wherein the adhesive is an adhesive film, a primer, or a spray glue. At 1144, the method 1100 may include applying an adhesive to the core before using the first non-planar metallic skin and the second non-planar metallic skin to deform and bond the core.
With reference to
At 1152, the method 1100 may include wherein using the first non-planar metallic skin and the second non-planar metallic skin to deform the core comprises inserting the first non-planar metallic skin over a punch, inserting the second non-planar metallic skin in a die, placing the core between the punch and the die, and deforming the core between the first non-planar metallic skin and the second non-planar metallic skin using the punch and the die. At 1156, the method 1100 may include wherein the punch comprises a heated punch and the die comprises a heated die. At 1160, the method 1100 may include wherein using the first non-planar metallic skin and the second non-planar metallic skin to deform the core comprises thermoforming the core.
The following paragraphs provide additional support for the claims of the subject application. One aspect provides a method for forming a non-planar composite, comprising: providing a first non-planar metallic skin and a second non-planar metallic skin, providing a substantially planar core between the first non-planar metallic skin and the second non-planar metallic skin, and using the first non-planar metallic skin and the second non-planar metallic skin (1) to deform the core between the first non-planar metallic skin and the second non-planar metallic skin and (2) to bond the core to one or more of the first non-planar metallic skin and the second non-planar metallic skin.
The method may additionally or alternatively include, wherein the first non-planar metallic skin has a shape comprising a first face and a second face that forms an angle of at least 15 degrees with respect to a plane of the first face, and the second non-planar metallic skin has substantially the shape of the first non-planar metallic skin. The method may additionally or alternatively include forming a feature comprising one or more of a rib, boss, and hole in the first non-planar metallic skin or the second non-planar metallic skin. The method may additionally or alternatively include, wherein the first non-planar metallic skin and the second non-planar metallic skin comprise different materials.
The method may additionally or alternatively include, wherein the first non-planar metallic skin has a shape defining a four-sided open top enclosure, and the second non-planar metallic skin has substantially the shape of the first non-planar metallic skin. The method may additionally or alternatively include, wherein using the first non-planar metallic skin and the second non-planar metallic skin to deform the core comprises inserting the first non-planar metallic skin over a punch, inserting the second non-planar metallic skin in a die, placing the core between the punch and the die, and compressively deforming the core between the first non-planar metallic skin and the second non-planar metallic skin using the punch and the die. The method may additionally or alternatively include, wherein the punch comprises a heated punch and the die comprises a heated die. The method may additionally or alternatively include, wherein using the first non-planar metallic skin and the second non-planar metallic skin to deform the core comprises thermoforming the core.
The method may additionally or alternatively include applying an adhesive to one or more of the first non-planar metallic skin and the second non-planar metallic skin prior to using the first non-planar metallic skin and the second non-planar metallic skin to deform and bond the core. The method may additionally or alternatively include applying an adhesive to the core before using the first non-planar metallic skin and the second non-planar metallic skin to deform and bond the core. The method may additionally or alternatively include, wherein the adhesive is an adhesive film, a primer, or a spray glue. The method may additionally or alternatively include, wherein the core comprises a thermosetting polymer.
Another aspect provides a composite, comprising: a first non-planar metallic skin, a second non-planar metallic skin, and a polymeric core between the first non-planar metallic skin and the second non-planar metallic skin, wherein the polymeric core is deformed from a planar configuration via compressive forming by the first non-planar metallic skin and the second non-planar metallic skin.
The composite may additionally or alternatively include, wherein the polymeric core is bonded to one or more of the first non-planar metallic skin and the second non-planar metallic skin via the compressive forming. The composite may additionally or alternatively include, wherein the polymeric core is deformed via compressive forming using a heated punch and a heated die.
The composite may additionally or alternatively include, wherein the first non-planar metallic skin has a shape comprising a first face and a second face that forms an angle of at least 15 degrees with respect to a plane of the first face, and the second non-planar metallic skin has substantially the shape of the first non-planar metallic skin. The composite may additionally or alternatively include, wherein the first non-planar metallic skin has a shape defining a four-sided open top enclosure, and the second non-planar metallic skin has substantially the shape of the first non-planar metallic skin.
The composite may additionally or alternatively include, wherein the first non-planar metallic skin and the second non-planar metallic skin comprise different materials. The composite may additionally or alternatively include an adhesive applied to one or more of the first non-planar metallic skin, the second non-planar metallic skin, and the core prior to the compressive forming.
Another aspect provides a method for forming a non-planar composite, comprising: providing a first non-planar metallic skin and a second non-planar metallic skin, providing a substantially planar thermosetting polymer core between the first non-planar metallic skin and the second non-planar metallic skin, and using the first non-planar metallic skin and the second non-planar metallic skin (1) to thermoform the core between the first non-planar metallic skin and the second non-planar metallic skin and (2) to bond the core to one or more of the first non-planar metallic skin and the second non-planar metallic skin.
It will be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various acts illustrated and/or described may be performed in the sequence illustrated and/or described, in other sequences, in parallel, or omitted. Likewise, the order of the above-described processes may be changed.
The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.