Deformation Behavior and Precipitation Features in a Stretched Al–Cu Alloy at Intermediate Temperatures

Abstract

Deformation behavior and precipitation features of an Al–Cu alloy are investigated using uniaxial tensile tests at intermediate temperatures. It is found that the true stress drops with the decreased strain rate or the increased deformation temperature. The number of substructures and the degree of grain elongation decrease with the raised temperature or the decreased strain rate. At high temperatures or low strain rates, some dynamic recrystallized grains can be found. The type of precipitates is influenced by the heating process before hot tensile deformation. The content and size of precipitates increase during tensile deformation at intermediate temperatures. As the temperature increases over 200 °C, the precipitation process (Guinier Preston zone (G.P. zones)→θ′′ phase→θ′ phase) is enhanced, resulting in increased contents of θ′′ and θ′ phases. However, θ′′ and θ′ phases prefer to precipitate along the {020}Al direction, resulting in an uneven distribution of phases. Considering the flow softening degree and the excessive heterogeneous precipitation of θ′′ and θ′ phases during hot deformation, the reasonable strain rate and temperature are about 0.0003 s−1 and 150 °C, respectively.

Dynamic Softening Mechanism and an Improved Unified Constitutive Model for an Al–Cu–Mn–Fe–Zr Alloy during Warm Deformation

“…First, the studied alloy sheet was solution‐treated at 535 °C for 40 min. [ 5 ] The solution‐treated microstructures are shown in Figure . There are some elongated grains, and almost no substructures can be found.…”

“…So, it is widely applied to manufacture the critical parts of aerospace equipment such as fuel tanks, pressure vessels, and so on. [ 5–7 ] During the manufacture of these parts, the forming parameters greatly affect the microstructures and properties. [ 8,9 ] Therefore, it is essential to research the flow behavior and microstructure evolution of Al–Cu alloys in forming process.…”

Forming Quality and Microstructure Evolution of AA6061‐T6 Aluminum Alloy Joint during Flow Drill Screwing Process

“…The morphology and volume of the strengthening phase in the aluminum alloy are greatly affected by strain rate and temperature. [35] The number of strengthening phases in Figure 5g is significantly reduced, indicating that the strengthening phases in the thread edge region are almost completely dissolved. Therefore, the temperature in this region during FDS is higher than the melting temperature of the strengthening phase, [36] and due to the insufficient aging time in the cooling process, the nanostrengthening phase in this region cannot be well precipitated, which will inevitably lead to the decreased strength of the region.…”

Prediction of Mechanical Properties by Artificial Neural Networks to Characterize the Plastic Behavior of Aluminum Alloys

“…On the other hand, they have an excellent workability and machinability and allow a large number of surface finishes [ 5 ]. Aluminum is a ductile and malleable material that can be shaped using a wide variety of techniques; however, its alloys have very different properties that significantly affect its forming behavior [ 6 , 7 ].…”