Modeling the Hot Ductility of AA6061 Aluminum Alloy After Severe Plastic Deformation

Abstract

Solutionized AA6061 aluminum alloy was processed by equal-channel angular pressing followed by cold rolling. The hot ductility of the material was studied after severe plastic deformation. The hot tensile tests were carried out in the temperature range of 300-500°C and at the strain rates of 0.0005-0.01 s À1 . Depending on the temperature and strain rate, the applied strain level exhibited significant effects on the hot ductility, strain-rate sensitivity, and activation energy. It can be suggested that the possible mechanism dominated the hot deformation during tensile testing is dynamic recovery and dislocation creep. Constitutive equations were developed to model the hot ductility of the severe plastic deformed AA6061 alloy.

Deformation and strengthening mechanisms of a carbon nanotube reinforced aluminum composite

“…Both CYS ( Fig.10(a)) and UCS (Fig.10(b)) decreased with increasing temperature at a strain rate of 0.001 s -1 . This could be attributed to the augmented thermal activation of the composite and the kinetic energy of the metal matrix which boosted the dislocation movements at higher temperatures [55], causing the observed decrease in Fig.10(a) and (b). (14)…”

Performance of Thermo-Mechanically Processed AA7075 Alloy at Elevated Temperatures—From Microstructure to Mechanical Properties

“…With increasing the deformation temperature and decreasing strain rate, the strength of the as-received T6 material decreases substantially, attesting the activation of softening mechanisms i.e., dynamic recovery (DRV) and dynamic recrystallization (DRX) at such high temperatures [20,26]. For in-depth evaluation of the behavior in these temperature ranges, tensile strength in many studies is considered, e.g., [31,39]. At lower deformation temperatures (200, 250, and 300 • C), the flow stress curves show a softening after reaching tensile stress without ever reaching the steady-state region (Figure 3).…”

“…Elevated temperature response of aluminum alloys is of interest for estimation of critical force levels for any application-oriented loading event as well as for metal forming at elevated temperatures [21,22,[28][29][30][31][32][33]. Many researchers utilized hot compression, tension, and torsion experiments to obtain flow curves at elevated temperatures [21,22,[28][29][30][31][32][33]. Instability phenomena during tensile testing are a barrier toward constitutive analysis.…”

Prediction of Flow Stress and Characterizing the Deformation Mechanism of As‐Extruded 7005 Aluminum Alloy

“…- \frac{Q}{R T} \left.\right)$$where is the strain rate (s −1 ), σ is the flow stress generated during deformation (MPa), α is the stress multiplier (an additional adjustable parameter), A is the structure factor, n is the stress exponent, Q is the activation energy associated with the deformation mechanism during thermal deformation (J mol −1 ), [ 27 ] R is the universal gas constant (8.314 J mol −1 K −1 ), and T is the deformation temperature (K). This equation is applicable across various stress levels.…”

“…The significant decrease in activation energy from 202 to 163 kJ mol −1 over the entire deformation period indicates a change in the deformation mechanism during deformation. [ 27 ] The range of Q values during deformation (163–202 kJ mol −1 ) is greater than the activation energy for self‐diffusion in pure Al (144 kJ mol −1 ), grain boundary diffusion (84 kJ mol −1 ), and dislocation pipe diffusion (82 kJ mol −1 ). [ 41 ] This suggests that solute atoms (Zn, Mg, or Zr) or precipitates (MgZn 2 or Al3Zr) in the as‐extruded 7005 Al alloy (Al–4.8Zn–1.8 Mg–0.1Zr) hinder the diffusion of Al atoms and the movement of dislocations by introducing solute drag and precipitate pinning effects.…”