Patent Application
20140044385
The disclosure relates to slide bearings comprising an aluminum alloy mesh and a sliding layer applied to the aluminum alloy, wherein the slide bearing reduces corrosion of underlying metal parts.
In the metal consuming industries, such as automotive industries, there are five existing types of steel corrosions, namely (i) uniform corrosion, (ii) crevice corrosion, (iii) pitting corrosion, (iv) cosmetic corrosion, and (v) galvanic corrosion. Galvanic corrosion also referred to as two-metal or bimetallic corrosion occurs when dissimilar metals or metal alloys are in contact in the presence of an electrolyte and or moisture. The more active, also called “anodic” metal or alloy corrodes while the more noble, also called “cathodic” metal or alloy remains undamaged. For example, on the galvanic scale copper or copper containing alloys, such as bronze, are less active than steel. Accordingly, if bronze-containing fabrics or parts are applied in the steel housing of a machine or automotive part, galvanic corrosion will damage the steel housing.
As such, materials to inhibit galvanic corrosion of the steel housing are needed.
In a first aspect, a method of reducing corrosion of a corrosive metal containing work piece includes providing a corrosive metal containing work piece. The corrosive metal containing work piece can have a non-planar surface. The method can further include covering at least about 10% of the non-planar surface with a laminate. The laminate can include an aluminum alloy mesh having a first major surface and a second major surface. The laminate can further include a sliding layer overlying the first major surface. The sliding layer can be in direct contact with the aluminum alloy mesh. The second major surface of the aluminum alloy mesh can be in direct contact with the at least 50% of the non-planar surface.
In another aspect, a corrosion protection article can include a bushing. The bushing can be in a non-planar shape. The bushing can further be shaped to enfold a work piece. The work piece can have a non-planar surface. The bushing can include an aluminum alloy mesh having a first major surface and a second major surface. The bushing can further include a sliding layer overlying the first major surface. The sliding layer can be in direct contact with the aluminum alloy mesh.
In one further aspect, an article can include a first body. A portion of the first body can moveably engage a second body. The first body can have a contoured external surface. The first body can further have a contoured internal surface. The first body can include an aluminum alloy mesh. The first body can include a sliding layer. The sliding layer can overlie the aluminum alloy mesh. The sliding layer can include the external surface. The aluminum alloy mesh can include the internal surface of the first body.
In yet another aspect, a method of reducing corrosion at an interface of two ferrous body parts includes providing a first ferrous body part. The first ferrous body part can include a contoured shape. The contoured shape can include a first major surface area. The first ferrous body can be shaped to engage a second ferrous body. The method can further include overlying the first major surface area with the second ferrous body. A second surface of the second ferrous body can contact the first major surface area. The first major surface and the second major surface can include corrosive metal containing material. The first ferrous body part can include a corrosive metal containing carrier. The first ferrous body part can further include an aluminum alloy mesh. The aluminum alloy mesh can overlie the corrosive metal containing carrier material. The first ferrous body part can further include a sliding layer. The sliding layer can overlie the aluminum alloy mesh.
In a further aspect, a corrosion guard can include a bushing. The bushing can include a corrosive metal containing carrier. The corrosive metal containing carrier can be adapted to overly a ferrous work piece. The bushing can further include an aluminum alloy mesh having a first major surface and a second major surface. The first major surface of the aluminum alloy mesh can overlie the corrosive metal containing carrier. The bushing can further include a sliding layer. The sliding layer can overlie the second major surface of the aluminum alloy mesh.
The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
The use of the same reference symbols in different drawings indicates similar or identical items.
In the metal working industry, work pieces of different metallic compositions are combined. Such combination can be the cause of galvanic corrosion, especially where work pieces are moveably engaged. For example, door hinges in the automobile industry are composed of parts that are in long-lasting frictional use and concurrently exposed to the elements of nature. Often, mores stable metals or alloys, such as copper or bronze, are employed in some parts in the door hinges, for examples, in rivets, linings, ferrules. These elements are the cause of galvanic corrosion near or at the moveable part thereby reducing the lifetime of the door hinge.
Aluminum is a more active metal than steel. Accordingly in the presence of an electrolyte and/or moisture, an aluminum part in contact with the steel would corrode. Moreover, aluminum forms a dense aluminum oxide layer which is essentially inert and prevents further corrosion. If the aluminum oxide layer is impacted by mechanical use, such as friction thereby exposing aluminum metal, the metal continues to serve as an anodic metal, thereby maintaining the surrounding steel in a cathodic or corrosion-protected mode.
The tensile strength of aluminum, however, is too poor to make aluminum a stress bearing element such as a component in an automobile door hinge. Accordingly, aluminum alloys that provide an ideal mechanical property profile are better suited for such mechanical demand. Such alloys may also function as corrosion reducing components as long as the alloy itself remains anodic or more active than the surrounding steel housing.
In a first embodiment, a method of reducing corrosion of a corrosive metal containing work piece includes providing a corrosive metal containing work piece. The corrosive metal containing work piece can have a non-planar surface. The method can further include covering at least about 50% of the non-planar surface with a laminate. The laminate can include an aluminum alloy mesh having a first major surface and a second major surface. The laminate can further include a sliding layer overlying the first major surface. The sliding layer can be in direct contact with the aluminum alloy mesh. The second major surface of the aluminum alloy mesh can be in direct contact with the at least 50% of the non-planar surface.
The corrosive metal containing work piece includes corrosive metals and alloys comprising corrosive metals. The corrosive metal can include iron, aluminum, lithium, sodium, potassium, magnesium, calcium, strontium, barium, titanium, vanadium, chromium, manganese, cobalt, zinc, cadmium, gallium, indium, germanium, tin, lead, and any combination thereof. In one embodiment, the corrosive metal containing work piece comprises an iron containing work piece. In one further embodiment, the corrosive metal containing work piece consists of an iron containing work piece.
In another embodiment, the covering can include at least about 20%, such as at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 98% of the non-planar surface. In yet one further embodiment, the covering is not greater than about 99.9%, such as not greater than about 90%, not greater than about 60%, or not greater than about 40% of the non-planar surface.
In another embodiment, a corrosion protection article can include a bushing. The bushing can be in a non-planar shape. The bushing can further be shaped to enfold a work piece. The work piece can have a non-planar surface. The bushing can include an aluminum alloy mesh 102 having a first major surface and a second major surface. The bushing can further include a sliding layer overlying the first major surface. The sliding layer can be in direct contact with the aluminum alloy mesh 102.
In another embodiment, the bushing can be shaped complementary to the work piece. In yet another embodiment, the bushing can be engaged with the work piece and the second major surface of the aluminum alloy mesh 102 is in direct contact with the non-planar surface of the work piece. The work piece can be a corrosive metal containing work piece. In another embodiment, the work piece includes steel.
In one further embodiment, an article can include a first body. A portion of the first body can moveably engage a second body. The first body can have a contoured external surface. The first body can further have a contoured internal surface. The first body can include an aluminum alloy mesh 102. The first body can include a sliding layer 104. The sliding layer 104 can overlie the aluminum alloy mesh 102. The sliding layer 104 can include the external surface. The aluminum alloy mesh 102 can include the internal surface of the first body.
In yet another embodiment, a method of reducing corrosion at an interface of two ferrous body parts includes providing a first ferrous body part. The first ferrous body part can include a contoured shape. The contoured shape can include a first major surface area. The first ferrous body can be shaped to engage a second ferrous body. The method can further include overlying the first major surface area with the second ferrous body. A second surface of the second ferrous body can contact the first major surface area. The first major surface and the second major surface can include corrosive metal containing material. The first ferrous body part can include a corrosive metal containing carrier. The first ferrous body part can further include an aluminum alloy mesh 102. The aluminum alloy mesh 102 can overlie the corrosive metal containing carrier material 106. The first ferrous body part can further include a sliding layer 104. The sliding layer 104 can overlie the aluminum alloy mesh 102. In embodiments, the first ferrous body, the second ferrous body, the corrosive metal containing material, or corrosive metal containing carrier can include steel.
In one further embodiment, a corrosion guard can include a bushing. The bushing can include a corrosive metal containing carrier 106. The corrosive metal containing carrier can be adapted to overly a ferrous work piece. The bushing can further include an aluminum alloy mesh 102 having a first major surface and a second major surface. The first major surface of the aluminum alloy mesh 102 can overlie the corrosive metal containing carrier 106. The bushing can further include a sliding layer 104. The sliding layer 104 can overlie the second major surface of the aluminum alloy mesh 102.
In one embodiment, the corrosion guard can include an adhesive layer (not shown in
In one embodiment, the aluminum alloy mesh 102 can include an alloy of aluminum with the group consisting of magnesium, calcium, strontium, barium, scandium, titanium, vanadium, manganese, corrosive metal, cobalt, nickel, copper, zinc, gallium, indium, thalium, germanium, tin, lead, and any combination thereof. In one particular embodiment, the aluminum alloy mesh 102 includes an aluminum magnesium alloy. In yet another embodiment, the aluminum alloy mesh 102 consist essentially of an aluminum magnesium alloy. In one embodiment, the aluminum magnesium alloy includes at least about 3 wt % magnesium, such as at least about 3.5 wt % magnesium, at least about 3.7 wt % magnesium, at least about 3.9 wt % magnesium, at least about 4.0 wt % magnesium, at least about 4.1 wt % magnesium, at least about 4.2 wt % magnesium, at least about 4.3 wt % magnesium, at least about 4.4 wt % magnesium, at least about 4.5 wt % magnesium, at least about 4.6 wt % magnesium, at least about 4.7 wt % magnesium, at least about 4.8 wt % magnesium, at least about 4.9 wt % magnesium, at least about 5.0 wt % magnesium, at least about 5.5 wt % magnesium, at least about 6.0 wt % magnesium, or at least about 6.5 wt % magnesium. In another embodiment, the aluminum magnesium alloy includes not greater than about 10 wt % magnesium, such as not greater than about 9 wt %, not greater than about 8 wt %, not greater than about 7 wt %, or not greater than about 6 wt %.
In another embodiment, the aluminum magnesium alloy includes at least about 85 wt % aluminum, such as at least about 87 wt % aluminum, at least about 89 wt % aluminum, at least about 90 wt % aluminum, at least about 91 wt % aluminum, at least about 92 wt % aluminum, at least about 93 wt % aluminum, at least about 93.5 wt % aluminum, at least about 94 wt % aluminum, at least about 94.5 wt % aluminum, at least about 95 wt % aluminum, or at least about 95.5 wt % aluminum. In another embodiment, the aluminum magnesium alloy includes not greater than about 96 wt % aluminum, such as not greater than about 95 wt % aluminum, not greater than about 94 wt % aluminum, not greater than about 92 wt % aluminum, not greater than about 90 wt % aluminum, not greater than about 88 wt % aluminum.
In yet another embodiment, the alloys can have the stoichiometric description AlMgii, wherein n=0.5, 1, 2, 3, 4, 5, 6, or 7. In one particular embodiment, the alloy can be AlMg5.
In one embodiment, the alloy mesh 102 comprises a woven mesh having a warp wire and a weft wire. In one embodiment, the warp wire and the weft wire can have the same thickness. In another embodiment, the warp wire has a thickness d1 and the weft wire has a thickness d2 and the ratio of d2/d1 can be at least about 1.5, such as at least about 2, at least about 2.5, or even at least about 3.0. In another embodiment, the ratio is not greater than about 8.0, or not greater than about 5.0. In another embodiment, the alloy mesh can be formed in the pattern of a diamond wire screen. The wires can be have a square, rectangular, or circular cross-section.
In one embodiment, the aluminum alloy mesh 102 has a mesh size of at least 10 mesh/inch, such as at least 11 mesh/inch, at least 13 mesh/inch, at least 15 mesh/inch, at least 17 mesh inch, at least 19 mesh/inch, or at least 21 mesh/inch. In another embodiment, the mesh size is not greater than 30 mesh/inch, such as not greater than 28 mesh/inch, not greater than 26 mesh/inch, not greater than 22 mesh/inch, not greater than 18 mesh/inch, or not greater than 16 mesh/inch.
In yet another embodiment, the aluminum alloy mesh 102 has a thickness of at least about 0.1 mm, such as at least about 0.2 mm, at least about 0.3 mm, at least about 0.4 mm, at least about 0.5 mm, or at least about 0.6 mm. In another embodiment the aluminum alloy mesh 102 has a thickness of not greater than about 0.8 mm, such as not greater than about 0.6 mm, not greater than about 0.5 mm, or not greater than about 0.4 mm.
With respect to the sliding layer 104, in embodiments, the sliding layer 104 can include a fluoropolymer. In another embodiment, the sliding layer 104 consists essentially of a fluoropolymer. The fluoropolymer can be selected from the group consisting of polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF) and polyvinyl fluoride (PVF), a combination thereof, and a laminated film comprising two or more thereof.
In embodiments, the sliding layer 104 can have a thickness of at least about 0.05 mm, such as at least about 0.1 mm, at least about 0.15 mm, at least about 0.2 mm, at least about 0.25 mm, at least about 0.3 mm, at least about 0.35 mm, at least about 0.4 mm, or at least about 0.45 mm.
In other embodiment, the sliding layer 104 has a thickness of not greater than about 5 mm, such as not greater than about 4.5 mm, not greater than about 4 mm, not greater than about 3.5 mm, not greater than about 3 mm, not greater than about 2.5 mm, not greater than about 2 mm, not greater than about 1.5 mm, not greater than about 1 mm, not greater than about 0.5 mm.
In yet one further embodiment, the sliding layer 104 can further include a filler. The filler can be selected from fibers, glass fibers, carbon fibers, aramids, inorganic materials, ceramic materials, carbon, glass, graphite, aluminum oxide, molybdenum sulfide, bronze, silicon carbide, woven fabrics, powders, spheres, thermoplastic materials, polyimide (PI), polyamidimide (PAI), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSO2), liquid crystal polymers (LCP), polyether ether ketones (PEEK) aromatic polyesters (Ekonol), mineral materials, wollastonite, barium sulfate, and any combination thereof. In one embodiment, the sliding layer 104 consists essentially of a fluoropolymer and a filler.
In addition to the aforementioned metal parts, the work piece of the embodiments can include a car part, a machine part, a building element, or a construction piece. In one particular embodiment, the car part is a door hinge.
Addressing the physical properties of the ally mesh, the aluminum alloy mesh 102 can have a tensile strength of at least about 70 MPa, such as at least about 100 MPa, at least about 150 MPa, at least about 200 MPa, at least about 250 MPa, or at least about 300 MPa. In another embodiment, the aluminum alloy mesh 102 has a tensile strength of not greater than about 350 MPa, such as not greater than about 300 MPa, not greater than about 250 MPa, or not greater than about 200 MPa. In a particular embodiment, the aluminum alloy mesh 102 has a tensile strength between about 300 MPa and about 350 MPa.
In another embodiment, the aluminum alloy mesh 102 has an electrical resistivity of at least about 0.02 (Ωmm2)/m, such as at least about 0.03 (Ωmm2)/m, at least about 0.04 (Ωmm2)/m, at least about 0.05 (Ωmm2)/m, or at least about 0.06 (Ωmm2)/m. In another embodiment, the aluminum alloy mesh 102 has an electrical resistivity of not greater than about 0.07 (Ωmm2)/m, such as not greater than about 0.06 (Ωmm2)/m, not greater than about 0.05 (Ωmm2)/m, or not greater than about 0.04 (Ωmm2)/m. In one particular embodiment, the aluminum alloy mesh 102 has an electrical resistivity between about 0.055 (Ωmm2)/m and about 0.065 (Ωmm2)/m.
Another type of an aluminum or aluminum alloy mesh material is an expanded or stretched aluminum or aluminum alloy. Contrary to the mesh depicted in
Another aspect for plain bearings as disclosed in
In one embodiment, the density of plain bearings as disclosed in
In yet another aspect, embodiments according to the two foregoing paragraphs can further be laminated on a metal support to form a laminate according to
For automobile door hinges, two tests were conducted, a salt spray test to evaluate the corrosion properties of an assembled door hinge and a door durability test to evaluate the performance of bushings and plain bearings comprising the aluminum alloy mesh.
Salt Spray Test
Hinges with a bushing 304 comprising an AlMg5 aluminum mesh (HAL) and hinges with a bronze mesh (HBR) were subjected to a salt spray test according to DIN ISO 9227:2006 NSS or ASTM B117. Samples were passivated with Zn and included a steel backing layer. The employed spray method was a neutral Salt Spray (Fog) of an aqueous NaCl solution at a concentration of 50 g/L. The Chamber temperature was maintained at 35° C., the pH value was between 6.5 and 7.3. The hinges were visually investigated for corrosion after 24 hours of salt spray testing and after 408 hours of salt spray testing. After 240 hours the HBR showed red corrosion over the entire hinge. Table 1 summarizes the test results.
The Salt Spray Test clearly identifies the improvement of a bushing comprising an aluminum mesh over the bronze bushings with respect to galvanic corrosion. In another test according to ASTM B117, shown in Table 2, samples of aluminum samples underwent salt spray testing until they show some red rust and/or delamination.
Door Durability Test
Car doors comprising hinges having bushings 304 including an AlMg5 aluminum alloy mesh (HAL) and hinges with a bronze mesh (HBR) were subjected to 100,000 cycles of load stress. The door drop test is a specific OEM procedure. In this test a car door of a specific weight is connected with two hinges to an column. The end of the door is stressed with a gravitational load of a specified amount. After removing the load, plastic deformation is measured. The door must not drop more than 0.3 mm to pass the test.
The drop of the door part hinge and the car body part of the hinge were determined after 100,000 cycles. Table 3 summarizes the results.
Since the relative drop of the door hinges are comparable, the hinges comprising aluminum alloy mesh bushings fulfill the same industrial demand as their bronze containing analogs.
Density Measurement
The density for sliding layers of a bushing 304 comprising an AlMg5 aluminum mesh (HAL) and hinges with a bronze mesh (HBR) were determined. The hinges did not include another metal support. HAl had a density of 2.242 g/cm3 and HBR measured a density of 4.235 g/cm3.
PTFE has a density of about 2.20 g/cm3. As can be seen from the foregoing data, the increase of the density for HAL is minimal, i.e. less than 10% while a bronze mesh almost doubles the density of a PTFE sliding layer (4.235/2.20=1.925)
Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.
In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.
After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.
This application claims priority under 35 U.S.C. §119(e) to U.S. Patent Application No. 61/671,674 entitled “CORROSIONS REDUCING FLEXIBLE PLAIN BEARING MATERIAL AND METHOD OF FORMING THE SAME,” by Zivko Andelkovski, filed Jul. 13, 2012, which is assigned to the current assignee hereof and incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61671674 | Jul 2012 | US |
