scholarly journals Hot Deformation Characteristics and Processing Parameter Optimization of Al–6.32Zn–2.10Mg Alloy Using Constitutive Equation and Processing Map

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 360
Author(s):  
Zhengbing Xiao ◽  
Qiang Wang ◽  
Yuanchun Huang ◽  
Jiawei Hu ◽  
Ming Li
Keyword(s):  
Constitutive Equation ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Processing Map ◽  
Electron Backscatter Diffraction ◽  
Flow Behavior ◽  
Processing Parameters ◽  
Z Parameter ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Hot compression tests over the temperature range from 350 °C to 500 °C and strain rates range from 0.001 s−1 to 1 s−1 for homogenized Al–6.32Zn–2.10Mg alloy were carried out on a Gleeble-3800 thermal simulation machine to characterize its hot deformation behavior. At the same time, a modified Arrhenius constitutive equation was established to describe the flow behavior of the alloy, whose average absolute error is 2.89%, which proved to have an excellent predictive effect on the flow stress of the alloy. The hot processing map of the alloy was established, and the stability processing parameters were 460–500 °C and 0.01–0.08 s−1. Then, the Z parameter processing map and activation energy processing (AEP) maps were established for further optimization. Eventually, the optimal processing parameters of the alloy was 460–500 °C (0.03–0.08 s−1). Then, the microstructure of specimens was observed using electron backscatter diffraction. Based on the findings the reasonability of the AEP map and Z parameter map was verified. Finally, electron backscatter diffraction (EBSD) techniques were used to analyze the evolution of the grain structure during the deformation process. It was found that dynamic recovery (DRV) was the main softening mechanism of Al–6.32Zn–2.10Mg. Continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) operated together with the increase of strain, but CDRX was confirmed as the dominant DRX mechanism.

scholarly journals Investigation on Sub-Solvus Recrystallization Mechanisms in an Advanced γ-γ’ Nickel-Based Superalloy GH4151

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4553
Author(s):  
Shaomin Lv ◽  
Jinbin Chen ◽  
Xinbo He ◽  
Chonglin Jia ◽  
Kang Wei ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Energy Surface ◽  
Electron Backscatter Diffraction ◽  
True Strain ◽  
Continuous Dynamic Recrystallization ◽  
Nickel Based Superalloy ◽  
Transmission Electron ◽  
Continuous Dynamic ◽  
Backscatter Diffraction

Sub-solvus dynamic recrystallization (DRX) mechanisms in an advanced γ-γ’ nickel-based superalloy GH4151 were investigated by isothermal compression experiments at 1040 °C with a strain rate of 0.1 s−1 and various true strain of 0.1, 0.3, 0.5, and 0.7, respectively. This has not been reported in literature before. The electron backscatter diffraction (EBSD) and transmission electron microscope (TEM) technology were used for the observation of microstructure evolution and the confirmation of DRX mechanisms. The results indicate that a new dynamic recrystallization mechanism occurs during hot deformation of the hot-extruded GH4151 alloy. The nucleation mechanism can be described as such a feature, that is a primary γ’ (Ni3(Al, Ti, Nb)) precipitate embedded in a recrystallized grain existed the same crystallographic orientation, which is defined as heteroepitaxial dynamic recrystallization (HDRX). Meanwhile, the conventional DRX mechanisms, such as the discontinuous dynamic recrystallization (DDRX) characterized by bulging grain boundary and continuous dynamic recrystallization (CDRX) operated through progressive sub-grain merging and rotation, also take place during the hot deformation of the hot-extruded GH4151 alloy. In addition, the step-shaped structures can be observed at grain boundaries, which ensure the low-energy surface state during the DRX process.

A 3D FIB Investigation of Dynamic Recrystallization in a Cu-Sn Bronze

2012 ◽  
Vol 715-716 ◽  
pp. 498-501 ◽  
Author(s):  
Ali Gholinia ◽  
Ian Brough ◽  
John F. Humphreys ◽  
Pete S. Bate
Keyword(s):  
Dynamic Recrystallization ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Beam ◽  
Bronze Alloy ◽  
Ebsd Data ◽  
Nucleation Sites ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Relationship Of

A combination of electron backscatter diffraction (EBSD) and focused ion beam (FIB) techniques were used to obtain 3D EBSD data in an investigation of dynamic recrystallization in a Cu-2%Sn bronze alloy. The results of this investigation show the origin of the nucleation sites for dynamic recrystallization and also elucidates the orientation relationship of the recrystallized grains to the deformed, prior grains and between the dynamically recrystallized grains.

Effect of Rolling Parameters on the Low-Temperature Toughness and Microstructure of High-Strength Linepipe Steel

2016 ◽  
Author(s):  
C. Stallybrass ◽  
A. Völling ◽  
H. Meuser ◽  
F. Grimpe
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Electron Backscatter Diffraction ◽  
High Strength ◽  
Processing Parameters ◽  
Small Scale ◽  
Electron Backscatter ◽  
Low Temperature Toughness ◽  
Backscatter Diffraction ◽  
Scanning Electron

In recent years, large-diameter pipe producers around the world have witnessed a growing interest to develop gas fields in arctic environments in order to fulfill the energy demand. High-strength linepipe grades are attractive for economic reasons, because they offer the benefit of a reduced wall thickness at a given operating pressure. Excellent low-temperature toughness of the material is essential under these conditions. Modern high-strength heavy plates used in the production of UOE pipes are produced by thermomechanical rolling followed by accelerated cooling (TMCP). The combination of high strength and high toughness of these steels is a result of the bainitic microstructure and is strongly influenced by the processing parameters. For this reason, the relationship between rolling and cooling parameters of heavy plate production, the low-temperature toughness and the microstructure is at the center of attention of the development efforts at Salzgitter Mannesmann Forschung (SZMF) in collaboration Salzgitter Mannesmann Grobblech (SMGB). It has been shown previously that a variation of the processing parameters has a direct influence on the microstructure and correlates with mechanical properties that are accessible via small-scale tests. Modern characterization methods such as scanning electron microscopy in combination with electron backscatter diffraction have broadened our understanding of the underlying mechanisms and have helped to define processing conditions for the production of heavy plates with optimized low-temperature toughness in small scale tests. Within the present paper, the results of a recent laboratory investigation of the effect of a systematic variation of rolling parameters on the microstructure and low-temperature toughness of as-rolled and pre-strained Charpy specimens are discussed. In these trials, final rolling temperatures above the onset of the ferrite-austenite transformation and cooling stop temperatures above the martensite start temperature were selected. The microstructure of the plates was investigated by scanning electron microscopy and electron backscatter diffraction. In a series of Charpy tests in a specific temperature range, it was found that plate material in the as-rolled condition is not strongly sensitive to variations of the selected processing parameters, whereas pre-straining the Charpy specimens made it possible to assess the potential of individual processing concepts particularly with regard to low-temperature toughness. In addition to Charpy testing, the toughness was also quantified via instrumented drop-weight tear (DWT) testing. By comparing total energy values from regular pressed-notch DWT-test specimens to J-integral values determined in drop-weight testing of pre-fatigued DWT-test specimens, the impact of variations of specimen type on material tearing resistance is shown.

Nucleation and Texture Development during Dynamic Recrystallization of Copper

2005 ◽  
Vol 495-497 ◽  
pp. 1195-1200 ◽  
Author(s):  
D.T. McDonald ◽  
John F. Humphreys ◽  
Pete S. Bate
Keyword(s):  
Dynamic Recrystallization ◽  
Electron Backscatter Diffraction ◽  
Boundary Migration ◽  
Deformation Texture ◽  
Texture Development ◽  
Polycrystalline Copper ◽  
High Angle ◽  
Resolution Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Dynamic recrystallization and texture development in polycrystalline copper have been investigated. Specimens were deformed in channel-die plane strain compression to true strains from 0.1 to 0.7 within the temperature range 200°C to 600°C, and the resulting microstructures were investigated with the use of high resolution electron backscatter diffraction (EBSD). Dynamic recrystallization in copper was initiated by the bulging of pre-existing high angle grain boundaries (HAGB), and occurred primarily by strain induced boundary migration (SIBM). Increasing misorientations from parent to dynamically recrystallizing grains indicated the occurrence of lattice rotations within the bulges, leading, in some cases to the formation of a HAGB behind the bulge. Discrimination between recrystallized and deformed components in material which had partially undergone dynamic recrystallization was carried out, followed by texture analysis. This revealed most of the recrystallized material to have orientations close to that of the deformed material, however, some remote orientations were observed which could not be related to the deformation texture by twin or 40° <111> relationships.

Cross Section Analysis of Cu Filled TSVs Based on High Throughput Plasma-FIB Milling

2012 ◽  
Author(s):  
Frank Altmann ◽  
Jens Beyersdorfer ◽  
Jan Schischka ◽  
Michael Krause ◽  
German Franz ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Section ◽  
High Throughput ◽  
Cross Sections ◽  
Electron Backscatter Diffraction ◽  
Grain Structure ◽  
Electron Backscatter ◽  
Section Surface ◽  
Backscatter Diffraction ◽  
Section Analysis

Abstract In this paper the new Vion™ Plasma-FIB system, developed by FEI, is evaluated for cross sectioning of Cu filled Through Silicon Via (TSV) interconnects. The aim of the study presented in this paper is to evaluate and optimise different Plasma-FIB (P-FIB) milling strategies in terms of performance and cross section surface quality. The sufficient preservation of microstructures within cross sections is crucial for subsequent Electron Backscatter Diffraction (EBSD) grain structure analyses and a high resolution interface characterisation by TEM.

Sign in / Sign up

Export Citation Format

Share Document