Aluminum alloy material and method for producing aluminum alloy material

Abstract

An aluminum alloy material has a composition containing 3% by mass or more and 10% by mass or less of Fe and the balance of Al and incidental impurities, and a structure including a matrix and a compound. The matrix is composed mainly of Al, the compound contains Al and Fe, and a relative density is 85% or more. In any cross section, the matrix has an average crystal grain size of 1,100 nm or less, and the compound has an average major-axis length of 100 nm or less.

1 . An aluminum alloy material comprising:
 a composition containing 3% by mass or more and 10% by mass or less of Fe and the balance of Al and incidental impurities; and   a structure including a matrix and a compound,   wherein the matrix is composed mainly of Al,   the compound contains Al and Fe,   a relative density is 85% or more, and   in any cross section, the matrix has an average crystal grain size of 1,100 nm or less, and the compound has an average major-axis length of 100 nm or less.   
     
     
         2 . The aluminum alloy material according to  claim 1 , wherein the average crystal grain size is 600 nm or less, and the average major-axis length is 35 nm or less. 
     
     
         3 . The aluminum alloy material according to  claim 1 , wherein when a plurality of square measurement regions each having a side length of 500 nm are chosen in the cross section, an average number of the compounds having a major-axis length of 5 nm or more and 100 nm or less in the measurement regions is 10 or more. 
     
     
         4 . The aluminum alloy material according to  claim 3 , wherein the average number is 80 or more and 175 or less. 
     
     
         5 . The aluminum alloy material according to  claim 1 , having a tensile strength of 300 MPa or more. 
     
     
         6 . The aluminum alloy material according to  claim 5 , having an elongation at break of 1% or more. 
     
     
         7 . A method for producing an aluminum alloy material, comprising:
 a step of rapidly cooling a melt of an aluminum alloy containing 3% by mass or more and 10% by mass or less of Fe and the balance of Al and incidental impurities to produce a powdery or flaky material in which the Fe is dissolved;   a step of subjecting the material to warm forming at a temperature of 400° C. or lower to form a dense body having a relative density of 85% or more; and   a step of subjecting the dense body to heat treatment at a temperature of 400° C. or lower.   
     
     
         8 . A method for producing an aluminum alloy material, comprising:
 a step of rapidly cooling a melt of an aluminum alloy containing 3% by mass or more and 10% by mass or less of Fe and the balance of Al and incidental impurities to produce a powdery or flaky material in which the Fe is dissolved;   a step of subjecting the material to cold forming to form a dense body having a relative density of 85% or more; and   a step of subjecting the dense body to heat treatment at a temperature of 400° C. or lower.   
     
     
         9 . The method for producing an aluminum alloy material according to  claim 7 , wherein, in X-ray diffraction of the dense body, a peak intensity of a compound containing Al and Fe is 1/10 or less relative to a peak intensity of an aluminum phase. 
     
     
         10 . The method for producing an aluminum alloy material according to  claim 8 , wherein, in X-ray diffraction of the dense body, a peak intensity of a compound containing Al and Fe is 1/10 or less relative to a peak intensity of an aluminum phase.