An aluminum alloy according to the present invention includes 1.2% by mass to 4.0% by mass of copper, 4.0% by mass to 14.0% by mass of zinc, 0.5% by mass to 4.0% by mass of magnesium, 0.01% or less of silicon, and 0.01% or less of iron, with the balance containing aluminum and inevitable impurities, and has an average equivalent circle crystal grain size of 500 nm or less.

An aluminum alloy according to the present invention includes 1.2% by mass to 4.0% by mass of copper, 4.0% by mass to 14.0% by mass of zinc, 0.5% by mass to 4.0% by mass of magnesium, 0.01% or less of silicon, and 0.01% or less of iron, with the balance containing aluminum and inevitable impurities, and has an average equivalent circle crystal grain size of 500 nm or less.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.

The present invention relates to the technical field of manufacturing of metal materials, and in particular to a 7000-series aluminum alloy wire for additive manufacturing and a preparation method thereof. The wire was prepared by subjecting an Al—Ti—B intermediate alloy containing TiB.sub.2 particles generated in situ to severe plastic deformation to obtain an intermediate alloy containing TiB.sub.2 nanoparticles having a particle size of 50-1,000 nm or a mixture of two different particles; using the intermediate alloy containing TiB.sub.2 nanoparticles as a matrix raw material, adding other metal or intermediate alloy for smelting to obtain an alloy melt; preparing a wire blank with the alloy melt; subjecting the wire blank to hot rolling, drawing, intermediate annealing and surface treatment to obtain an Al—Zn—Mg—Cu alloy wire reinforced by particles at nano scale or submicron scale.

A method for producing an aluminum alloy extrusion includes: conducting extrusion processing using a casted billet of an aluminum alloy containing 6.0 to 7.0% by mass of Zn, 1.5 to 2.0% by mass of Mg, 0.20 to 1.50% by mass of Cu, 0.10 to 0.25% by mass of Zr, 0.005 to 0.05% by mass of Ti, 0.15 to 0.35% by mass of Mn, 0.25% by mass or less of Sr, content of Mn and Zr and Sr being 0.10 to 0.50% by mass, with the balance being Al and inevitable impurities to obtain an aluminum alloy extrusion; cooling the extrusion to 100° C. or less at a cooling rate of 50 to 750° C./min immediately after the extrusion processing; and then conducting an aging treatment which is performed in one-stage or two-stage and a heat treatment which is performed at higher temperature for a shorter time than the aging treatment.

A method for producing an aluminum alloy extrusion includes: conducting extrusion processing using a casted billet of an aluminum alloy containing 6.0 to 7.0% by mass of Zn, 1.5 to 2.0% by mass of Mg, 0.20 to 1.50% by mass of Cu, 0.10 to 0.25% by mass of Zr, 0.005 to 0.05% by mass of Ti, 0.15 to 0.35% by mass of Mn, 0.25% by mass or less of Sr, content of Mn and Zr and Sr being 0.10 to 0.50% by mass, with the balance being Al and inevitable impurities to obtain an aluminum alloy extrusion; cooling the extrusion to 100° C. or less at a cooling rate of 50 to 750° C./min immediately after the extrusion processing; and then conducting an aging treatment which is performed in one-stage or two-stage and a heat treatment which is performed at higher temperature for a shorter time than the aging treatment.

An Al-based bearing alloy and a slide bearing incorporating the alloy exhibit high corrosion resistance and maintain high strength for a long period of time even in a high temperature environment. The Al-based bearing alloy and slide bearing includes an Al matrix, and acicular compounds which are needle-shaped that precipitate at a plurality of sites in a structure of the Al matrix, and that have a minor diameter and a major diameter.

An Al-based bearing alloy and a slide bearing incorporating the alloy exhibit high corrosion resistance and maintain high strength for a long period of time even in a high temperature environment. The Al-based bearing alloy and slide bearing includes an Al matrix, and acicular compounds which are needle-shaped that precipitate at a plurality of sites in a structure of the Al matrix, and that have a minor diameter and a major diameter.

Provided is a welded structural member with excellent stress corrosion cracking resistance, which includes: a 7000-series aluminum alloy material that has a chemical composition containing 6.6% by mass to 8.5% by mass of Zn, 1.0% by mass to 2.1% by mass of Mg, 0.10% by mass to 0.20% by mass of Zr, and 0.001% by mass to 0.05% by mass of Ti, with a remainder including Al and unavoidable impurities, and includes a metallographic structure that is a fibrous structure; and other aluminum alloy material welded with the 7000-series aluminum alloy material. In this welded structural member, when an electrical conductivity of the 7000-series aluminum alloy material before an artificial aging treatment is defined as X % IACS and the electrical conductivity of the 7000-series aluminum alloy material after the artificial aging treatment is defined as Y % IACS, the following equation is satisfied: 0.120≤(Y/X−1)≤0.250 is satisfied, and a difference in the electrical conductivity of the 7000-series aluminum alloy material between a mother portion other than a weld heat-affected zone and the weld heat-affected zone is 5% IACS or less.

Provided is a welded structural member with excellent stress corrosion cracking resistance, which includes: a 7000-series aluminum alloy material that has a chemical composition containing 6.6% by mass to 8.5% by mass of Zn, 1.0% by mass to 2.1% by mass of Mg, 0.10% by mass to 0.20% by mass of Zr, and 0.001% by mass to 0.05% by mass of Ti, with a remainder including Al and unavoidable impurities, and includes a metallographic structure that is a fibrous structure; and other aluminum alloy material welded with the 7000-series aluminum alloy material. In this welded structural member, when an electrical conductivity of the 7000-series aluminum alloy material before an artificial aging treatment is defined as X % IACS and the electrical conductivity of the 7000-series aluminum alloy material after the artificial aging treatment is defined as Y % IACS, the following equation is satisfied: 0.120≤(Y/X−1)≤0.250 is satisfied, and a difference in the electrical conductivity of the 7000-series aluminum alloy material between a mother portion other than a weld heat-affected zone and the weld heat-affected zone is 5% IACS or less.