Study on effects of powder and flake chemistry and morphology on the properties of Al-Cu-Mg-X-X-X powder metallurgy advanced aluminum alloys

The effects of alloy chemistry and particulate morphology on consolidation behavior and consolidated product properties in rapid solidification processed, powder-metallurgical Al-3Li-1.5Cu-1Mg-0.5Co-0.2Zr and Al-4.4Cu-1.5Mg-Fe-Ni-0.2Zr extrusions and forgings were studied. Microstructures and mechanical properties of both alloys are largely unaffected by particulate production method (vacuum atomization, ultrasonic atomization, or twin-roller quenching) and by particulate solidification rates between 1000 and 100,000 K/s. Consolidation processing by canning, cold compaction, degassing, and hot extrusion is sufficient to yield mechanical properties in the non-Li-containing alloy extrusions which are similar to those of 7075-Al, but ductilities and fracture toughnesses are inferior owing to poor interparticle bonding caused by lack of a vacuum-hot-pressing step during consolidation. Mechanical properties of extrusions are superior to those of forgings owing to the stronger textures produced by the more severe hot working during extrusion. The effects on mechanical properties of dispersoid size and volume fraction, substructural refinement, solid solution strengthening by Mg, and precipitate size and distribution are elucidated for both alloy types

Effect of Initial Temper on Mechanical Properties of Friction Stir Welded Al-2024 Alloy

The microstructural evolution and resultant mechanical properties during the friction stir welding (FSW) of precipitation strengthened aluminium alloys depend on initial temper as well as FSW process parameters. Al-2024 alloy under two different initial tempers, T3 and T8, was used in the present study. FSW bead-on-plate runs were performed at different values of process parameters (tool rotation rate and tool traverse speed). Microstructure and mechanical properties of the nugget region and heat affected zone (HAZ) were evaluated. Differential scanning calorimetry (DSC) revealed that in the nugget region, presence of Guinier-Preston-Bagaryatskii (GPB) zone results from the partial dissolution of Al2CuMg phase. The microstructure and tensile properties were found to be independent of the initial temper of the material in the nugget region. In the HAZ region, tensile properties increased at higher heat index values for T3 condition, and decreased monotonically for T8 condition

The Quasi-Static Deformation and Final Fracture Behavior of Aluminum Alloy 2219

In this paper is presented the results of an experimental study aimed at understanding the tensile deformation and fracture behavior of aluminum alloy 2219. Uniaxial tensile tests results reveal the alloy to have acceptable strength and ductility (elongation-to-failure) for both the anodized and non-anodized conditions. The ductility, quantified in terms of reduction in area, of the anodized sheet is marginally superior to the ductility of the non-anodized sheet. No drastic change in tensile fracture mode was evident as a function of anodized condition of the sheet. On a microscopic scale, tensile fracture surfaces of the alloy revealed features reminiscent of locally ductile and brittle failure mechanisms. The fracture behavior of the alloy is discussed in light of intrinsic microstructural features; deformation characteristics of the alloy, local stress state and grain boundary failure

An Investigation of the High Cycle Fatigue and Final Fracture Behavior of Aluminum Alloy 2219

In this research paper, the cyclic stress amplitude controlled fatigue response and fracture behavior of an Al-Cu (Aluminum Association designation 2219) is presented and discussed. The alloy was provided as a thin sheet in the T62 temper in the fully anodized condition. A small quantity of the as-provided sheet was taken and the surface carefully prepared to remove the thin layer of anodized coating. Test specimens of the alloy, prepared from the two sheets (anodized and non-anodized), were cyclically deformed under stress amplitude control at two different load ratios with the primary objective of establishing the conjoint influence of magnitude of cyclic stress, load ratio and intrinsic microstructural effects on cyclic fatigue life and final fracture characteristics. The high cycle fatigue resistance of the alloy is described in terms of maximum stress, load ratio, and microstructural influences on strength. The final fracture behavior of the alloy sheet is discussed in light of the concurrent and mutually interactive influences of intrinsic microstructural effects, deformation characteristics of the alloy microstructure, magnitude of cyclic stress, and resultant fatigue life

The High Cycle Fatigue and Fracture Behavior of Friction Stir Welded Aluminum Alloy 2024

In this research paper, the cyclic stress amplitude controlled fatigue response and fracture behavior of an Al-Cu-Mg alloy (Aluminum Association designation 2024) is presented and discussed. The alloy was friction stir welded in the T8 temper to provide two plates one having high tensile ductility and denoted as Plate A and the other having low tensile ductility and denoted as Plate B. Test specimens of the alloy, prepared from the two plates, were cyclically deformed under stress amplitude control at two different load ratios with the primary objective of documenting the conjoint influence of magnitude of cyclic stress, load ratio and intrinsic microstructural effects on cyclic fatigue life and final fracture characteristics. The high cycle fatigue resistance of the alloy is described in terms of maximum stress, R-ratio, and microstructural influences on strength. The final fracture behavior of the friction stir welded alloy is discussed in light of the concurrent and mutually interactive influences of intrinsic microstructural effects, deformation characteristics of the alloy microstructure, magnitude of cyclic stress, and resultant fatigue life