Aluminum alloy, aluminum-alloy hot-worked material, and manufacturing method thereof

Abstract

An aluminum alloy has a chemical composition that contains Sc: 0.01 mass % or more and 0.40 mass % or less, Mg: 0 mass % or more and 2.5 mass % or less, and Zr: 0 mass % or more and 0.4 mass % or less, the remainder being Al and unavoidable impurities. The compressive-deformation resistance, which is calculated based on the true stress when the aluminum alloy is deformed by compressing at a temperature of 450° C. and a strain rate of 1 s−1, is 62 MPa or less.

1 . An aluminum alloy having:
 Sc: 0.01 mass % or more and 0.40 mass % or less, Mg: 0 mass % or more and 2.5 mass % or less, and Zr: 0 mass % or more and 0.4 mass % or less;   wherein compressive-deformation resistance, which is calculated based on the true stress when deformed by compressing at a temperature of 450° C. and a strain rate of 1 s −1 , is 62 MPa or less.   
     
     
         2 . The aluminum alloy according to  claim 1 , wherein the Mg content is 0.2 mass % or more and 2.5 mass % or less. 
     
     
         3 . The aluminum alloy according to  claim 1 , wherein the Zr content is 0.01 mass % or more and 0.4 mass % or less. 
     
     
         4 . The aluminum alloy according to  claim 1 , wherein the aluminum alloy further contains one or two or more elements selected from the group consisting of Cu: greater than 0 mass % and 1.0 mass % or less, Mn: greater than 0 mass % and 1.0 mass % or less, Cr: greater than 0 mass % and 0.30 mass % or less, Ti: greater than 0 mass % and 0.10 mass % or less, and B: greater than 0 mass % and 0.10 mass % or less. 
     
     
         5 . An aluminum-alloy hot-worked material having:
 Sc: 0.01 mass % or more and 0.40 mass % or less, Mg: 0 mass % or more and 2.5 mass % or less, and Zr: 0 mass % or more and 0.4 mass % or less;   wherein:   Al—Sc-series second-phase particles are dispersed in the Al parent phase; and   the number density of the Al—Sc-series second-phase particles is 3,000 particles/μm 3  or higher.   
     
     
         6 . The aluminum-alloy hot-worked material according to  claim 5 , wherein the Mg content is 0.2 mass % or more and 2.5 mass % or less. 
     
     
         7 . The aluminum-alloy hot-worked material according to  claim 5 , wherein the Zr content is 0.01 mass % or more and 0.4 mass % or less. 
     
     
         8 . The aluminum-alloy hot-worked material according to  claim 5 , wherein the aluminum-alloy hot-worked material further contains one or two or more elements selected from the group consisting of Cu: greater than 0 mass % and 1.0 mass % or less, Mn: greater than 0 mass % and 1.0 mass % or less, Cr: greater than 0 mass % and 0.30 mass % or less, Ti: greater than 0 mass % and 0.10 mass % or less, and B: greater than 0 mass % and 0.10 mass % or less. 
     
     
         9 . The aluminum-alloy hot-worked material according to  claim 5 , wherein:
 the aluminum-alloy hot-worked material has a hollow part at at least one location surrounded by a wall part composed of aluminum alloy; and   a welding surface at at least one location, constituted by welding the aluminum alloys together, is formed on the wall part.   
     
     
         10 . A method of manufacturing an aluminum-alloy hot-worked material, comprising:
 performing hot working on the aluminum alloy according to  claim 1  in a state in which the temperature is within the range of 350° C. or higher and 550° C. or lower; and   before and/or after the hot-working step, holding the aluminum alloy for a total of 30 min or more at a hold temperature of 250° C. or higher and 550° C. or lower.   
     
     
         11 . The method according to  claim 10 , wherein, in the hot-working step, porthole extrusion is performed as the hot working on the aluminum alloy.