Process for manufacturing a part (20) including a formation of successive metal layers (20.sub.1 . . . 20.sub.n), which are superimposed on each other, each layer being formed by depositing a filler metal (15, 25), the filler metal being subjected to a supply of energy so as to become molten and to constitute, upon solidifying, said layer, the process being characterized in that the filler metal (15, 25) is an aluminum alloy including the following alloy elements (% by weight); Mg: 2.0%-5.0%; Zr: 0.5%-1.0%; Fe: 0.6%-3.0%; optionally Zn: ≤0.5%; optionally Cu: ≤0.5%; other alloy elements, in total ≤4.0%, and individually ≤1.0%; impurities: <0.05% individually, and in total <0.15%; remainder aluminum.

The invention concerns an aluminum extruded product as feedstock for forging comprising in weight percent Si: 0.6% to 1.4%, Fe: 0.01% to 0.15%, Cu: 0.05% to 0.60%, Mn: 0.4% to 1%, Mg: 0.4% to 1.2%, Cr: 0.05% to 0.25%, Zn≤0.2%, Ti≤0.1%, Zr≤0.05%, the rest being aluminium and unavoidable impurities having a content of less than 0.05% each, total being less than 0.15%, wherein the number density of Mn containing dispersed particles is at least equal to 2.5 particles per μm.sup.2, preferably 3.0 particles per μm. The invention also concerns the process to obtain the aluminum extruded product as feedstock for forging.

The invention concerns an aluminum extruded product as feedstock for forging comprising in weight percent Si: 0.6% to 1.4%, Fe: 0.01% to 0.15%, Cu: 0.05% to 0.60%, Mn: 0.4% to 1%, Mg: 0.4% to 1.2%, Cr: 0.05% to 0.25%, Zn≤0.2%, Ti≤0.1%, Zr≤0.05%, the rest being aluminium and unavoidable impurities having a content of less than 0.05% each, total being less than 0.15%, wherein the number density of Mn containing dispersed particles is at least equal to 2.5 particles per μm.sup.2, preferably 3.0 particles per μm. The invention also concerns the process to obtain the aluminum extruded product as feedstock for forging.

When a T1-tempered aluminum alloy extrusion is subjected to plastic working and thus formed into a product, crack occurrence is prevented during plastic working, and tensile residual stress of the product is reduced to improve stress corrosion cracking resistance. A T1-tempered 7000-series aluminum alloy extrusion is heated to a temperature range of 150° C. or higher, and then subjected to plastic working within the temperature range, and then cooled, and then subjected to artificial temper aging. An integral value (F.sub.140) of (T(t)−140).sup.2 is controlled to 5×10.sup.5 (° C..sup.2.Math.s) or less in a section of t.sub.1≤t≤t.sub.2, where t is time (s) from heating start, T(t) is temperature (° C.) of the extrusion at time t, t.sub.1 is time before the extrusion reaches 140° C. in a heating step, and t.sub.2 is time before the extrusion reaches 140° C. again in a cooling step.

When a T1-tempered aluminum alloy extrusion is subjected to plastic working and thus formed into a product, crack occurrence is prevented during plastic working, and tensile residual stress of the product is reduced to improve stress corrosion cracking resistance. A T1-tempered 7000-series aluminum alloy extrusion is heated to a temperature range of 150° C. or higher, and then subjected to plastic working within the temperature range, and then cooled, and then subjected to artificial temper aging. An integral value (F.sub.140) of (T(t)−140).sup.2 is controlled to 5×10.sup.5 (° C..sup.2.Math.s) or less in a section of t.sub.1≤t≤t.sub.2, where t is time (s) from heating start, T(t) is temperature (° C.) of the extrusion at time t, t.sub.1 is time before the extrusion reaches 140° C. in a heating step, and t.sub.2 is time before the extrusion reaches 140° C. again in a cooling step.

A continuous casting and rolling line for casting, rolling, and otherwise preparing metal strip can produce distributable metal strip without requiring cold rolling or the use of a solution heat treatment line. A metal strip can be continuously cast from a continuous casting device and coiled into a metal coil, optionally after being subjected to post-casting quenching. This intermediate coil can be stored until ready for hot rolling. The as-cast metal strip can undergo reheating prior to hot rolling, either during coil storage or immediately prior to hot rolling. The heated metal strip can be cooled to a rolling temperature and hot rolled through one or more roll stands. The rolled metal strip can optionally be reheated and quenched prior to coiling for delivery. This final coiled metal strip can be of the desired gauge and have the desired physical characteristics for distribution to a manufacturing facility.

A continuous casting and rolling line for casting, rolling, and otherwise preparing metal strip can produce distributable metal strip without requiring cold rolling or the use of a solution heat treatment line. A metal strip can be continuously cast from a continuous casting device and coiled into a metal coil, optionally after being subjected to post-casting quenching. This intermediate coil can be stored until ready for hot rolling. The as-cast metal strip can undergo reheating prior to hot rolling, either during coil storage or immediately prior to hot rolling. The heated metal strip can be cooled to a rolling temperature and hot rolled through one or more roll stands. The rolled metal strip can optionally be reheated and quenched prior to coiling for delivery. This final coiled metal strip can be of the desired gauge and have the desired physical characteristics for distribution to a manufacturing facility.

An aluminum alloy brazing sheet used for brazing of an aluminum material in an inert gas atmosphere or in vacuum is formed of a two-layer material in which a brazing material and a core material are stacked. The core material is formed of an aluminum alloy and has a grain size of 20 to 300 μm, and the aluminum alloy contains Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %. Si of 1.50 mass % or less, Fe of 1.00 mass % or less, and Ti of 0.10 to 0.30 mass %, with the balance being aluminum and inevitable impurities. The brazing material is formed of an aluminum alloy containing Si of 4.00 to 13.00 mass % with the balance being aluminum and inevitable impurities. In a drop-type fluidity test, a ratio α (α=K.sub.a/K.sub.b) of a fluid coefficient K.sub.a is 0.50 or more.

An aluminum alloy brazing sheet used for brazing of an aluminum material in an inert gas atmosphere or in vacuum is formed of a two-layer material in which a brazing material and a core material are stacked. The core material is formed of an aluminum alloy and has a grain size of 20 to 300 μm, and the aluminum alloy contains Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %. Si of 1.50 mass % or less, Fe of 1.00 mass % or less, and Ti of 0.10 to 0.30 mass %, with the balance being aluminum and inevitable impurities. The brazing material is formed of an aluminum alloy containing Si of 4.00 to 13.00 mass % with the balance being aluminum and inevitable impurities. In a drop-type fluidity test, a ratio α (α=K.sub.a/K.sub.b) of a fluid coefficient K.sub.a is 0.50 or more.

An aluminum alloy brazing sheet used for brazing of an aluminum material in an inert gas atmosphere or in vacuum is formed of a two-layer material in which a brazing material and a core material are stacked in this order. The core material is formed of an aluminum alloy and has a grain size of 20 to 300 μm, and the aluminum alloy contains Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass % or less, with the balance being aluminum and inevitable impurities. The brazing material is formed of an aluminum alloy containing Si of 4.00 to 13.00 mass % with the balance being aluminum and inevitable impurities, and, in a drop-type fluidity test, a ratio α (α=K.sub.a/K.sub.b) of a fluid coefficient K.sub.a is 0.50 or more.