Abstract:
A composite metal article provided in the present invention includes a carbon steel core and a dissimilar composite metal out-layer, said out-layer combined with the carbon steel core by high pressure forging. As the high pressure forging belongs to the precise forging type, which molded by the method of inpour the metal liquid into the cavity on high pressure, thus it can form a thin composite out-layer out of the carbon steel core; it can combined a composite out-layer with the complex structure carbon steel core thus form a complex structure railing and metal table/chair etc.; it can combined complex structure composite out-layer with the simplex structure carbon steel core thus form a complex structure railings and metal table/chair etc.; as there are no air holes on the composite out-layer surface, it has a precise and nice-looking surface and can manufacture products by a simple post-processing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority benefits to Chinese Patent Application No. 200720007249.0 filed on May 31, 2007 and No. 200720008322.6 filed on Sep. 21, 2007. The contents of all of the aforementioned specifications are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to metal articles of furniture and railings, and more particularly to a composite metal article. 
         [0004]    2. Description of the Related Art 
         [0005]    The most existing metal furniture and railings that used in gardening, e.g. indoor/outdoor handrail, banisters, guardrail of green belts or guarding windows, are made of carbon steel, stainless steel or stainless steel clad pipe. The guardrail of furniture made of carbon steel needed anticorrosive treatment to the carbon steel surface, these treatments usually include paint spraying, plastic spraying, zinc spraying, aluminium spaying, aluminium-magnesium alloy spraying or zinc-aluminium alloy spraying etc. These methods exist some disadvantages as following: firstly, it&#39;s easy rusty to occur rusty stains; secondly it doesn&#39;t benefit to the environmental protection; thirdly, the structures of products are too simple in effect, and can&#39;t endure a longtime-anticorrosion. The railings made of stainless steel are rarely rusty, but there still existing the following disadvantages: firstly, they cost much; secondly, there are too many noble metal to be used; thirdly, their structures are too simple. The manufacture process of railings made by stainless steel clad pipe is just covering a stainless steel cover to the carbon steel by mechanism, which solved the expensive and easy rusty problem, but there still existing the following disadvantages: firstly, because it&#39;s just covering a stainless steel cover to the carbon steel by mechanism, it can&#39;t create complex structure like carvings and figures; secondly, it increase the difficulty of manufacture and reduce the efficiency. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a composite metal article that solve the above-mentioned problems brought by the using of the carbon steel, stainless steel or stainless steel clad pipe in making railings. 
         [0007]    The present invention provides the following method: a composite metal article which include a carbon steel core and a dissimilar composite metal out-layer, said out-layer combined with the outer surface of the carbon steel core by high pressure forging. 
         [0008]    The term “composite out-layer”, as used herein, refer to be a copper, aluminium or zinc composite out-layer. 
         [0009]    The term “composite out-layer”, as used herein, refer to be a zinc-aluminium or aluminium-magnesium alloy composite out-layer. 
         [0010]    The said composite out-layer has a thickness of 1.0-5.0 mm. 
         [0011]    The term “carbon steel core”, as used herein, refer to a hollow carbon steel core. 
         [0012]    The term “carbon steel core”, as used herein, refer to a solid carbon steel core. 
         [0013]    The term “composite metal articles”, as used herein, have carvings. 
         [0014]    The present invention provides a composite metal railing, includes a carbon steel core and a dissimilar composite metal out-layer, the composite out-layer combined with the surface of the carbon steel core by high pressure forging. 
         [0015]    The present invention provides a composite metal table/chair, includes a board unit and a leg unit, at least one unit is composite unit, the composite unit includes a carbon steel core and a dissimilar composite metal out-layer which combined with the surface of the carbon steel core by high pressure forging. 
         [0016]    The composite metal article disclosed in the present invention, as the composite metal out-layer is combined with the surface of the carbon steel core by high pressure forging, has the advantages as following: firstly, as the high pressure forging belongs to the precise forging type, which molded by the method of inpouring the metal liquid to the cavity on high pressure, so it can form a thin composite out-layer out the carbon steel core; it can combined composite out-layer with the complex structure carbon steel core thus form a complex structure railing or metal table/chair; it can combined complex structure composite out-layer with the simplex structure carbon steel core thus form a complex structure railings and metal table/chair; secondly, as there are no air holes on the composite out-layer surface, it has a precise and nice-looking surface and can manufacture products by a simple post-processing; thirdly, it could have a quick processing speed, and high production efficiency; fourthly the total cost is low; fifthly, it is rustless and stainless; sixthly, it benefits to environmental protection; seventhly, it can maintain anticorrosion for a long time. The materials of the composite outer-layer are copper, aluminium, zinc, as they have low melting points and easy to forging, they can form thin composite out-layer and complex-structure articles. The thickness of the composite out-layer is 1.0-5.0 mm. The out-layer is thin, thus reduce the quantity of used metals and the cost is low. The Carbon steel core is hollow, which reduce the quantity of used carbon steel, lighten the articles. The composite articles are nice-looking for there are carvings on them. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Detailed description of the present invention are disclosed in connection with the following figures: 
           [0018]      FIG. 1  is a front view for illustrating the composite railings according to embodiment 1 
           [0019]      FIG. 2  is a sectional view for illustrating the composite railings according to embodiment 1 
           [0020]      FIG. 3  is a sectional view for illustrating the composite railings according to embodiment 2 
           [0021]      FIG. 4  is a sectional view for illustrating the composite railings according to embodiment 3 
           [0022]      FIG. 5  is a perspective view illustrating the gardening table according to embodiment 4 
           [0023]      FIG. 6  is a sectional view for illustrating the gardening table according to embodiment 5 
           [0024]      FIG. 7  is a sectional view for illustrating the gardening chair according to embodiment 6 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Embodiment 1 
       [0025]    A composite metal railing, as shown in  FIG. 1  and  FIG. 2 ,  FIG. 1  is a front view for illustrating the composite railings according to the embodiment 1.  FIG. 2  is a sectional view for illustrating the composite railings according to embodiment 1, includes a carbon steel core  10  and an aluminium composite out-layer  20 . In this embodiment, the material of the composite out-layer  20  is aluminium, without limitation, The other materials e.g. zinc, copper, zinc-aluminium alloy or magnesium-aluminium alloy are also suitable to the embodiment. 
         [0026]    The carbon steel core  10  is a solid core with the needed complex shape, combined with the composite out-layer  20  by high pressure forging. The thickness of composite out-layer  20  is 2 mm, and its outer shape is complex carving structure, so the products of composite railings form the complex carving structure. The shape of this embodiment is carving, without limitation, the other structures e.g. figures, animals are also makeable. 
         [0027]    Detailed description of the manufacture process of railings in the invention: 
         [0028]    P 100 , step of the manufacture process of core  10 , in which the needed shape of the carbon steel core are produced by hot rolling or cold rolling. 
         [0029]    P 200 , step of beginning, in which the needed working mould are put on the working machine, the mould is special steel mould and its inside cavity has the needed shape of railing. 
         [0030]    P 300 , step of setting, in which the carbon steel core  10  are put into the working mould. 
         [0031]    P 400 , step of high pressure forging, in which the melted aluminium liquid is inpoured to the working mould on high pressure, which will fuse to the carbon steel core  10   
         [0032]    P 500 , step of opening, in which the products are take out from the mould, being the railings with needed shape. There can also take some simple process, e.g. spraying to them or grinding to the corners and flanges when needed. 
       Embodiment 2 
       [0033]    A composite metal railing, as shown in  FIG. 3 , which is a sectional view for illustrating the composite railings according to embodiment 2, includes a carbon steel core  10  and a aluminium composite out-layer  20 . In this embodiment, the material of the composite out-layer  20  is aluminium, without limitation, The other materials e.g. zinc, copper, zinc-aluminium alloy or magnesium-aluminium alloy are also suitable to the embodiment. 
         [0034]    The carbon steel core  10  is a solid line stick, with regular rectangle on cross section, combined with the composite out-layer  20  by high pressure forging. The outer shape of the composite out-layer  20  is complex carving, thus the railing product form a complex carving structure. The shape of this embodiment is carving, without limitation, the other structures e.g. figures, animals are also makeable. 
       Embodiment 3 
       [0035]    A composite metal railing, as is shown in  FIG. 4 , which is a sectional view for illustrating the composite railings according to embodiment 3, includes a carbon steel core  10  and a aluminium composite out-layer  20 . In this embodiment, the material of the composite out-layer  20  is aluminium, without limitation, the other materials e.g. zinc, copper, zinc-aluminium alloy, magnesium-aluminium alloy are also suitable to the embodiment 
         [0036]    The carbon steel core  10  is a hollow line stick, with regular rectangle on cross section, combined with the composite out-layer  20  by high pressure forging. The outer shape of the composite out-layer  20  is complex carving, so the products of railings form the complex carving structure. The shape of this embodiment is carving, without limitation, the other structures e.g. figures, animals are also makeable. 
       Embodiment 4 
       [0037]    A composite metal gardening table, as shown in  FIG. 5  and  FIG. 6 ,  FIG. 5  is a perspective view and  FIG. 6  is a sectional view, both of them illustrating the gardening table according to embodiment 4 of the invention, includes the board unit  60 , leg unit  70  and rack unit  50 . 
         [0038]    Each of the board unit  60 , leg unit  70  and rack unit  50  is composite unit in this embodiment, without limitation, the other combinations are also suitable to the embodiment, e.g. composite board unit  60  with not-composite leg unit  70 , or composite leg unit  70  with not-composite board unit  60 . 
         [0039]    The composite unit includes a carbon steel core  30  and a composite aluminium out-layer  40 , the composite out-lay  40  combined with the carbon steel core  30  by high pressure forging, which makes that there aren&#39;t any surface of the carbon steel core directly contact with the air. In this embodiment, the material of the composite out-layer  40  is aluminium, without limitation, the other materials, e.g. zinc, copper, zinc-aluminium alloy, magnesium-aluminum alloy are also suitable to the embodiment 
         [0040]    The carbon steel core  30  is solid, with complex shape which matches the shape of board unit  60  or leg unit  70 . The core  30  combined with the composite our-layer  40  by high pressure forging, the thickness of the composite our-layer  40  is uniformly 2 mm, thus the whole shape of the composite unit present the needed shape of board unit  60  or leg unit  70 , e.g. carvings. In this embodiment, the shape is carving structure, without limitation, the other structures e.g. figures, animals etc. are also makable. There are ventholes in the carving structure of board unit  60  as shown in  FIG. 5 . 
         [0041]    Detailed description of the manufacture process of the composite unit: 
         [0042]    P 100 , step of the manufacture process of core  30 , in which the needed complex shape of carbon steel core  30 , e.g. carving, figures, animals, etc. are produced by hot rolling or cold rolling. 
         [0043]    P 200 , step of beginning, in which the needed working mould are put on the working machine, the mould is special steel mould and its inside cavity has the needed shape of railings. 
         [0044]    P 300 , step of setting, in which the carbon steel core  30  are put into the working mould. 
         [0045]    P 400 , step of high pressure forging, in which the melted aluminium liquid is inpoured to the working mould on high pressure, which will fuse to the carbon steel core 
         [0046]    P 500 , step of opening, in which the products are take out from the mould, being the railings with needed shape. There can also take some simple process, e.g. spraying to them or grinding to the corners and flanges when need 
         [0047]    After the board unit and leg unit are produced by the above-mentioned method, the board unit and the leg unit are assembled with each other by weld or bolt-joining. The joining part are directly manufactured on board unit, leg unit and rack unit. 
       Embodiment 5 
       [0048]    The difference in this embodiment to embodiment 4 is that: a composite metal gardening table, the composite unit includes a carbon steel core  30  and a composite aluminium out-layer  40 , the carbon steel core  30  is a solid regular stick, combined with the composite our-layer  40  by high pressure forging, the thickness of the composite our-layer  40  is nonuniform, thus the shape of the unit present to the needed complex structure of board unit  60  or leg unit  70 , e.g. carving. 
       Embodiment 6 
       [0049]    The difference in this embodiment to embodiment 4 is that: a composite metal gardening table, as shown in  FIG. 7 , which is a sectional view for illustrating the gardening chair according to the embodiment 6. The composite unit includes a carbon steel core  30  and a composite aluminium out-layer  40 . The carbon steel core  30  is hollow, with complex shape which matches the out-shape of board unit or leg unit  70 . 
       Embodiment 7 
       [0050]    A composite metal gardening chair includes board unit, leg unit and back unit. 
         [0051]    Each of the board unit, leg unit and back unit is composite unit in this embodiment, without limitation, the other combinations are also suitable to the embodiment, e.g. composite board unit with not-composite leg unit, or composite leg unit with not-composite board unit. 
         [0052]    The composite unit includes a carbon steel core and a composite aluminium out-layer, the composite out-lay combined with the carbon steel core  30  by high pressure forging, which makes that there aren&#39;t any surface of the carbon steel core directly contact with the air. In this embodiment, the material of the composite out-layer is aluminium, without limitation, the other materials e.g. zinc, copper, zinc-aluminium alloy, magnesium-aluminum alloy are also suitable to the embodiment 
         [0053]    The carbon steel core is solid, with complex structure which matches the shape of board unit or leg unit. The core combined with the composite our-layer by high pressure forging, the thickness of the composite our-layer  40  is uniformly 2 mm, thus the whole shape of the composite unit present the needed shape of board unit or leg unit, e.g. carving. In this embodiment the shape is carving structure, without limitation, the other structures, e.g. figures, animals etc. are also makable. There are ventholes in the carving structure of board unit 
         [0054]    Detailed description of the manufacture process of the composite unit: 
         [0055]    P 100 , step of the manufacture process of core, in which the needed complex shape of carbon steel core, e.g. carving, figures, animals, etc. are produced by hot rolling or cold rolling. 
         [0056]    P 200 , step of beginning, in which the needed working mould are put on the working machine, the mould is special steel mould and its inside cavity has the needed shape of railings. 
         [0057]    P 300 , step of setting, in which the carbon steel core are put into the working mould. 
         [0058]    P 400 , step of high pressure forging, in which the melted aluminum liquid is inpoured to the working mould on high pressure, which will fuse to the carbon steel core. 
         [0059]    P 500 , step of opening, in which the product are take out from the mould, being the railings with needed shape there also can take some simple process e.g. spraying to them or grinding to the corners and flanges when need 
         [0060]    After the board unit and leg unit are produced by the above method, the board unit and the leg unit are assembled with each other by weld or bolt-joining. The joining part are directly manufactured on board unit, leg unit and rack unit. 
         [0061]    Utility in Industry 
         [0062]    The present invention provides composite metal articles and production method therefore, wherein the carbon steel core combined with a composite stainless metal or alloy out-layer, which makes a quick processing speed, high production efficiency and low cost in manufacture, and it can widely used in industry field.