Hot Deformation Behavior of a New Al–Mn–Sc Alloy

Abstract

The hot deformation behavior of a new Al–Mn–Sc alloy was investigated by hot compression conducted at temperatures from 330 to 490 °C and strain rates from 0.01 to 10 s−1. The hot deformation behavior and microstructure of the alloy were significantly affected by the deformation temperatures and strain rates. The peak flow stress decreased with increasing deformation temperatures and decreasing strain rates. According to the hot deformation behavior, the constitutive equation was established to describe the steady flow stress, and a hot processing map at 0.4 strain was obtained based on the dynamic material model and the Prasad instability standard, which can be used to evaluate the hot workability of the alloy. The developed hot processing diagram showed that the instability was more likely to occur in the higher Zener–Hollomon parameter region, and the optimal processing range was determined as 420–475 °C and 0.01–0.022 s−1, in which a stable flow and a higher power dissipation were achieved.

Deformation Characteristics and Constitutive Equations for the Semi-Solid Isothermal Compression of Cold Radial Forged 6063 Aluminium Alloy

“…The constitutive model expresses the material’s dynamic response to the deformation amount, deformation temperature, and the strain rate during the plastic processing, which is crucial for the numerical simulation of the plastic deformation process using the finite element method and can be illustrated by Equation (4) [ 32 ], where, is the flow stress, MPa; is the strain of the material; is the strain rate, s −1 .…”

“…The Arrhenius equation can characterize the sensitivity of flow stress to strain rate and deformation temperature as well as having the advantages of concision and a high degree of agreement with actual deformation. Its expressions are shown in Equations (6)–(8) [ 32 , 33 , 34 ]. In general, the exponential law expressed in Equation (6) is suitable for the stresses low-level values while the exponential law expressed by Equation (7) is applicable for stresses at high-level values.…”

“…According to the principle of pressure processing [ 13 , 32 ], the amount of deformation inside the sample is uneven in the process of material compression and deformation. The deformation area can be divided into hard deformation region, huge deformation region, and free deformation region, as shown in Figure 11 a.…”

Hot Deformation Behavior and Processing Maps of 26CrMo7S Steel Used in Oil Exploration

“…It can be seen that the stress-strain curve of The experimental procedure and the hot compression test carried out on a Gleeble-3800 thermal simulation testing machine are presented following the schematic map in Figure 2. The experimental specimens with a diameter of 10 mm and a height of 15 mm were cut from the 26CrMo7S steel [17,18]. As depicted in the machining process/left side of Figure 2.…”

“…The relative error (RE) between the predicted value and the experimental value can be calculated with the average relative error (AAER), as is shown in Equation (17).…”