Aluminum alloy member and method for manufacturing same

Abstract

The present invention provides: an aluminum alloy member which can be manufactured at a relatively low cost and has a light weight, and which can have high dimensional accuracy under a high-temperature environment and is less likely to undergo the color-fading of a blackened surface even under a high-temperature environment, and has excellent heat resistance; and a method for manufacturing the aluminum alloy member with high efficiency. The aluminum alloy member according to the present invention comprises: a substrate which comprises an extruded material of an aluminum powder alloy having an Si content of 20 to 40% by mass and has an anodic oxide coating film formed on the surface thereof, and an electrolytically colored layer which is formed by precipitating a metal or a metal salt on voids in the anodic oxide coating film.

1 . An aluminum alloy member which comprises:
 an extruded material of an aluminum powder alloy having an Si content of 20 to 40% by mass, and   includes a substrate having an anodic oxide coating film on the surface, and   an electrolytically colored layer which is formed by precipitating a metal or a metal salt on voids in the anodic oxide coating film.   
     
     
         2 . The aluminum alloy member according to  claim 1 , wherein
 the aluminum powder alloy contains Si: 20 to 40% by mass, Mg: 0.2 to 1.2% by mass, Cu: more than 0 to 2% by mass or less, Fe: more than 0 to 2% by mass or less, Cr: more than 0 to 0.4% by mass or less, and the balance is composed of Al and unavoidable impurities.   
     
     
         3 . The aluminum alloy member according to  claim 1 , wherein
 the metal and the metal salt contain at least one of Ni, Co, Cu, Sn, Mn, Fe, Pb, Ca, Zn and Mg.   
     
     
         4 . The aluminum alloy member according to  claim 1 , wherein
 the linear expansion coefficient is 10×10 −6  to 23×10 −6 /K.   
     
     
         5 . The aluminum alloy member according to  claim 1 , wherein
 the difference between the L* value after the heat treatment and the L* value before the heat treatment held in an atmosphere of 200° C. for 100 hours is 3 or less.   
     
     
         6 . The aluminum alloy member according to  claim 1 , wherein the member is an optical member or a member for an optical member inspection device. 
     
     
         7 . A method for manufacturing an aluminum alloy member, which includes:
 a first step of manufacturing a substrate by subjecting an aluminum alloy powder having a Si content of 20 to 40% by mass to pressure molding, sintering and extrusion processing,   a second step of forming an anodic oxide film on the surface of the substrate, and   a third step of electrolytically coloring the substrate in an electrolytic solution containing a metal or a metal salt to form an electrolytically colored layer on the surface of the substrate by precipitating a metal or a metal salt on voids in the anodic oxide coating film.