Aluminum alloy, bar-like material, forge-formed article, machine-formed article, wear-resistant aluminum alloy with excellent anodized coat using the same and production methods thereof

Abstract

An aluminum alloy containing 5 to 12% (mass %; similarly applicable hereinafter) of Si, 0.1 to 1% of Fe, less than 1% of Cu and 0.3 to 1.5% of Mg and having the valance formed of Al and impurities is cast by a continuous casting process. When the cast mass consequently obtained is homogenized, then extruded and/or forged and/or machined and subjected to an anodizing treatment, the resultant formed article is endowed with excellent wear resistance because the anodized coat formed thereon in a thickness of 30 μm or more with hardness Hv of 400 or more allows the presence therein of eutectic Si particles having particle diameters in the range of 0.4 to 5.5 μm.

1 . An aluminum alloy that forms in consequence of an anodizing treatment an anodized coat having a thickness of 30 μm or more and hardness Hv of 4000 or more and allows a presence, in the coat, of eutectic Si particles having particle diameters in the range of 0.4 to 5.5 μm.  
     
     
         2 . An aluminum alloy that forms in consequence of an anodizing treatment an anodized coat having a thickness of 40 μm or more and hardness Hv of 4000 or more and allows a presence, in the coat, of eutectic Si particles having particle diameters in a range of 0.8 to 5.5 μm.  
     
     
         3 . An aluminum alloy according to  claim 1  or  claim 2 , which contains 5 to 12% (mass %; similarly applicable hereinafter) of Si, 0.1 to 1% of Fe, less than 1% of Cu and 0.3 to 1.5% of Mg, and has the balance formed of Al and impurities, has dispersed in a matrix thereof eutectic Si particles having particle diameters in a range of 0.4 to 5.5 μm, inclusive of 60% or more of the eutectic Si particles having particle diameters of 0.8 to 2.4 μm, and allows a presence of 4000 or more and less than 40000 eutectic Si particles per mm 2 .  
     
     
         4 . An aluminum alloy according to any one of  claims 1  to  3 , which when containing 9 to 12% of Si, has 80% or more of the eutectic Si particles with particle diameters of 0.8 to 2.4 μm.  
     
     
         5 . An aluminum alloy according to any one of  claims 1  to  4 , which contains substantially no Cu.  
     
     
         6 . An aluminum alloy according to any one of  claims 1  to  5 , further containing at least one component selected from among 0.1 to 1% of Mn, 0.04 to 0.3% of Cr, 0.04 to 0.3% of Zr and 0.01 to 0.1% of V.  
     
     
         7 . An aluminum alloy according to any one of  claims 1  to  6 , further comprising at least one component selected from among 0.01 to 0.3% of Ti, 0.0001 to 0.05% of B and 0.001 to 0.1% of Sr.  
     
     
         8 . An aluminum alloy according to any one of  claims 1  to  7 , wherein the aluminum alloy is a bar material cast by a continuous casting method.  
     
     
         9 . An aluminum alloy according to any one of  claims 1  to  7 , wherein the aluminum alloy is a bar material manufactured by a continuous casting method and then extruded or extruded and drawn.  
     
     
         10 . A bar material comprising the aluminum alloy according to any one of  claims 1  to  9 .  
     
     
         11 . A bar material according to  claim 10 , wherein the bar material is used as a sleeve part.  
     
     
         12 . A forged article resulting from subjecting the bar material according to  claim 10  or  claim 11  to a forging process.  
     
     
         13 . A machined article resulting from subjecting the bar material according to  claim 10  or  claim 11  or the forged article according to  claim 12  to a machining process.  
     
     
         14 . A wear-resistant aluminum alloy having an anodized coat having a thickness of 30 μm or more and hardness Hv of 400, which allows a presence, in the anodized coat, of eutectic Si particles of particle diameters in a range of 0.4 to 5.5 μM.  
     
     
         15 . A wear-resistant aluminum alloy excelling in hardness of an anodized coat, which allows a presence, in an anodized coat, of eutectic Si particles of particle diameters in a range of 0.8 to 5.5 μm and forms the coat in a thickness of 40 μm or more and with hardness Hv of 400 or more.  
     
     
         16 . A sleeve part excelling in hardness of an anodized coat, resulting from subjecting the machined article according to  claim 13  to an anodizing treatment.  
     
     
         17 . A method for the production of a wear-resistant aluminum alloy excelling in hardness of an anodized coat, comprising casting the aluminum alloy according to any one of  claims 3  to  7  by a continuous casting process to form a cast mass, homogenizing the cast mass to form a homogenized cast mass, then extruding and/or forging and/or machining the homogenized cast mass to form a formed cast mass and subjecting the formed cast mass to an anodizing treatment, thereby allowing a presence, in the anodized coat, of eutectic Si particles of particle diameters in a range of 0.4 to 5.5 μm and forming the coat in a thickness of 30 μm or more and with hardness Hv of 400 or more.  
     
     
         18 . A method for the production of a sleeve part excelling in hardness of an anodized coat and formed of an aluminum alloy, comprising casting the aluminum alloy according to any one of  claims 3  to  7  by a continuous casting process to form a cast mass, homogenizing the cast mass to form a homogenized cast mass, then extruding and/or forging and/or machining the homogenized cast mass to form a formed cast mass and subjecting the formed cast mass to an anodizing treatment, thereby allowing a presence, in the anodized coat, of eutectic Si particles of particle diameters in a range of 0.8 to 5.5 μm and forming the coat in a thickness of 40 μm or more and with hardness Hv of 400 or more.