Dynamic recrystallization behavior and processing map of the Cu–Cr–Zr–Nd alloy

Abstract

Hot deformation behavior of the Cu–Cr–Zr–Nd alloy was studied by hot compressive tests in the temperature range of 650–950 °C and the strain rate range of 0.001–10 s−1 using Gleeble-1500D thermo-mechanical simulator. The results showed that the flow stress is strongly dependent on the deformation temperature and the strain rate. With the increase of temperature or the decrease of strain rate, the flow stress significantly decreases. Hot activation energy of the alloy is about 404.84 kJ/mol and the constitutive equation of the alloy based on the hyperbolic-sine equation was established. Based on the dynamic material model, the processing map was established to optimize the deformation parameters. The optimal processing parameters for the Cu–Cr–Zr–Nd alloy hot working are in the temperature range of 900–950 °C and strain rate range of 0.1–1 s−1. A full dynamic recrystallization structure with fine and homogeneous grain size can be obtained at optimal processing conditions. The microstructure of specimens deformed at different conditions was analyzed and connected with the processing map. The surface fracture was observed to identify instability conditions.

Correlation among the Power Dissipation Efficiency, Flow Stress Course, and Activation Energy Evolution in Cr-Mo Low-Alloyed Steel

“…The creation of the AE maps requires the calculation of activation energy values under all thermomechanical conditions. In most cases, however, the activation energy is considered to be a material constant (so-called apparent activation energy) or, at most, strain dependent [21,26,[51][52][53][54]. In order to deal with the activation energy as a strain, strain rate, and temperature dependent parameter, the method utilized, e.g., in [55,56] has been employed.…”

“…Since the end of the 2nd millennium, hot processing maps, introduced on the basis of the dynamic material model (DMM), have been being broadly used in the sense of the optimization of hot forming processes (forging, rolling, etc.) [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. It is well known that the processing map displays the distribution of power dissipation efficiency and metallurgical instability in the strain rate–temperature coordinates under the specific value of strain.…”

Extension of Experimentally Assembled Processing Maps of 10CrMo9-10 Steel via a Predicted Dataset and the Influence on Overall Informative Possibilities

“…Since the end of the 20th century, processing maps, i.e., power dissipation maps superimposed by flow instability maps, have been extensively studied as a very convenient tool for the optimization of hot forming processes, such as rolling, forging, etc. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These maps simply display the combinations of thermomechanical conditions, i.e., strain, strain rate, and deformation temperature, which are suitable for the forming processes of an examined material.…”

“…Saxena et al [6] compiled power dissipation and flow instability maps of a Zr-2.5Nb zirconium alloy, while Duan et al [14] developed processing maps for a Pb-Mg-10Al-0.5B alloy. Various other steels and alloys have also been studied on the basis of processing maps, e.g., austenitic heat-resistant stainless steel (Zhou et al [7]), Ni-based superalloy (Zhang et al [9]), Cu-Cr-Zr-Nd alloy (Zhang et al [11]), NiTiNb shape memory alloy (Wang at al. [15]), nanoalumina composite (Suresh et al [8]), etc.…”

Hot Deformation Behavior and Processing Maps of a High Al-low Si Transformation-Induced Plasticity Steel: Microstructural Evolution and Flow Stress Behavior

“…Constitutive modeling of alloys [14][15][16][17][18][19][20] has been accomplished recently to predict their hot deformation behavior. Based on the principles of dynamic material modeling [21], the processing maps have been successfully developed [22][23][24][25]. Researches show that the variety of thermal-mechanical condition in hot deformation process causes complex evolutions of dynamic recrystallization (DRX) content, dislocation density and grain size [26].…”