scholarly journals Hot Deformation Treatment of Grain-Modified Mg–Li Alloy

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4557
Author(s):  
Mariusz Król ◽  
Przemysław Snopiński ◽  
Marek Pagáč ◽  
Jiří Hajnyš ◽  
Jana Petrů
Keyword(s):  
Hot Deformation ◽  
Cast Alloy ◽  
Material Model ◽  
Strain Rate Range ◽  
Al Alloy ◽  
Grain Refiner ◽  
Systematic Analysis ◽  
Dynamic Material Model ◽  
Instability Map

In this work, a systematic analysis of the hot deformation mechanism and a microstructure characterization of an as-cast single α-phase Mg–4.5 Li–1.5 Al alloy modified with 0.2% TiB addition, as a grain refiner, is presented. The optimized constitutive model and hot working terms of the Mg–Li alloy were also determined. The hot compression procedure of the Mg–4.5 Li–1.5 Al + 0.2 TiB alloy was performed using a DIL 805 A/D dilatometer at deformation temperatures from 250 °C to 400 °C and with strain rates of 0.01–1 s−1. The processing map adapted from a dynamic material model (DMM) of the as-cast alloy was developed through the superposition of the established instability map and power dissipation map. By considering the processing maps and microstructure characteristics, the processing window for the Mg–Li alloy were determined to be at the deformation temperature of 590 K–670 K and with a strain rate range of 0.01–0.02 s−1.

Hot Deformation Behavior and Processing Map of 25%SiCp/2009A1 Composite

2016 ◽  
Vol 849 ◽  
pp. 409-415 ◽  
Author(s):  
Shao Hua Wei ◽  
Yan Qiang Liu ◽  
Jun Hui Nie ◽  
Tao Zuo ◽  
Zi Li Ma ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Constant Strain Rate ◽  
Material Model ◽  
Strain Rate Range ◽  
Deformation Condition ◽  
Processing Maps ◽  
Rate Range ◽  
Temperature Range ◽  
Dynamic Material Model

The hot deformation characteristics of 25%SiCp/2009A1 composite fabricated by powder metallurgy route were studied by thermal compaction testing on Gleeble-3800 hot-simulation machine in the temperature range of 370~520 °C and strain rate range of 0.01~10 s-1. The processing maps of 25%SiCp/2009A1 composites were developed on the basis of dynamic material model. The results show that the flow stress decreased with increasing deformation temperature at a constant strain rate, and increased with increasing strain rate at a constant temperature. The processing maps present unsteady zones at high strain rate (≥1 s-1). There are a few interfaces of particle-matrix separated and the particle itself cracked. There was significant dynamic recovery and dynamic recrystallization occurred in the higher temperature and lower strain rate region. The optimum hot deformation condition of the composites attained by the maps were in the temperature range of 450~490 °Cand in the strain rate range of 0.01~0.1 s-1.

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

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 22
Author(s):  
Weiqi Kang ◽  
Yi Yang ◽  
Sheng Cao ◽  
Lei Li ◽  
Shewei Xin ◽  
...  
Keyword(s):  
Flow Stress ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Material Model ◽  
Strain Rates ◽  
Hot Workability ◽  
Hot Deformation Behavior ◽  
Hollomon Parameter ◽  
Dynamic Material Model ◽  
Optimal Processing

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.

Hot Simulation Compression of In Situ TiBw/Ti6Al4V Composites with Novel Network Microstructure

2013 ◽  
Vol 762 ◽  
pp. 382-386
Author(s):  
Lu Jun Huang ◽  
Yu Zi Zhang ◽  
Lin Geng
Keyword(s):  
Processing Map ◽  
Peak Flow ◽  
Flow Instability ◽  
Material Model ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Compression Behavior ◽  
Dynamic Material Model ◽  
Network Microstructure

The hot compression behavior of in situ TiB whiskers reinforced Ti6Al4V (TiBw/Ti6Al4V) composites with a novel network microstructure is investigated in the temperature range of 900-1100°C and strain rate range of 0.001-10 s-1. The results show that all the stress-strain curves of the composites display peak flow, softening and steady-state. Moreover, the peak flow stress decreases with increasing temperatures and decreasing strain rates. Processing map of the composite is constructed using the dynamic material model (DMM). Dynamic recrystallization (DRX) of α phase is observed in the deformation region corresponding with peak efficiency of the processing map. However, the flow instability region ranged from 900 to 1100°C at strain rates higher than 1.0 s-1should be avoided.

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

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1218 ◽  
Author(s):  
Petr Opěla ◽  
Petr Kawulok ◽  
Rostislav Kawulok ◽  
Ondřej Kotásek ◽  
Pavol Buček ◽  
...  
Keyword(s):  
Material Model ◽  
Strain Rate Range ◽  
Processing Maps ◽  
Low Alloy Steel ◽  
Network Approach ◽  
Compression Tests ◽  
Neural Network Approach ◽  
Rate Range ◽  
Dynamic Material Model ◽  
Artificial Neural Network Approach

Processing maps embody a supportive tool for the optimization of hot forming processes. In the present work, based on the dynamic material model, the processing maps of 10CrMo9-10 low-alloy steel were assembled with the use of two flow curve datasets. The first one was obtained on the basis of uniaxial hot compression tests in a temperature range of 1073–1523 K and a strain rate range of 0.1–100 s−1. This experimental dataset was subsequently approximated by means of an artificial neural network approach. Based on this approximation, the second dataset was calculated. An important finding was that the additional dataset contributed significantly to improving the informative ability of the assembled processing maps in terms of revealing potentially inappropriate forming conditions.

scholarly journals Research on the Hot Deformation Behavior of the Casting NiTi Alloy

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6173
Author(s):  
Chengchuang Tao ◽  
Hongjun Huang ◽  
Ge Zhou ◽  
Bowen Zheng ◽  
Xiaojiao Zuo ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Niti Alloy ◽  
Rate Sensitivity ◽  
Material Model ◽  
Instability Criterion ◽  
Hot Deformation Behavior ◽  
Dynamic Material Model ◽  
Ti2ni Phase

The hot deformation behavior and processing maps of the casting NiTi alloy were studied at the deformation temperature of 650–1050 °C and the strain rate of 5 × 10−3–1 s−1 by Gleeble-3800 thermal simulating tester. The variation of the strain rate sensitivity exponent m and the activation energy Q under different deformation conditions (T = 650–1050 °C, ε˙ = 0.005–1 s−1) were obtained. The formability of the NiTi alloy was the best from 800 °C to 950 °C. The constitutive equation of the casting NiTi alloy was constructed by the Arrhenius model. The processing map of the casting NiTi alloy was plotted according to the dynamic material model (DMM) based on the Prasad instability criterion. The optimal processing areas were at 800–950 °C and 0.005–0.05 s−1. The microstructure of the casting NiTi alloy was analyzed by TEM, SEM and EBSD. The softening mechanisms of the casting NiTi alloy were mainly dynamic recrystallization of the Ti2Ni phase and the nucleation and growth of fine martensite.

scholarly journals An inverse problem for the characterization of dynamic material model parameters from a single SHPB test

2011 ◽  
Vol 10 ◽  
pp. 1603-1608 ◽  
Author(s):  
C. Hernandez ◽  
A. Maranon ◽  
I.A. Ashcroft ◽  
J.P. Casas-Rodriguez
Keyword(s):  
Inverse Problem ◽  
Material Model ◽  
Model Parameters ◽  
Dynamic Material Model ◽  
Shpb Test

scholarly journals Constitutive Equation and Hot Processing Map of Mg-16Al Magnesium Alloy Bars

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3107 ◽  
Author(s):  
Zongwen Ma ◽  
Fengya Hu ◽  
Zhongjun Wang ◽  
Kuijun Fu ◽  
Zhenxiong Wei ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Material Model ◽  
Strain Rate Range ◽  
Dislocation Slip ◽  
Unstable Flow ◽  
Al Content ◽  
Dynamic Material Model ◽  
Compression Deformation

A Gleeble-2000D thermal simulation machine was used to investigate the high-temperature hot compression deformation of an extruded Mg-16Al magnesium alloy under various strain rates (0.0001–0.1 s−1) and temperatures (523–673 K). Combined with the strain compensation Arrhenius equation and the Zener–Hollomon (Z) parameter, the constitutive equation of the alloy was constructed. The average deformation activation energy, Q, was 144 KJ/mol, and the strain hardening index (n ≈ 3) under different strain variables indicated that the thermal deformation mechanism was controlled by dislocation slip. The Mg-16Al alloy predicted by the Sellars model was characterized by a small dynamic recrystallization (DRX) critical strain, indicating that Mg17Al12 particles precipitated during the compression deformation promoted the nucleation of DRX. Hot processing maps of the alloy were established based on the dynamic material model. These maps indicated that the high Al content, precipitation of numerous Mg17Al12 phases, and generation of microcracks at low temperature and low strain rate led to an unstable flow of the alloy. The range of suitable hot working parameters of the experimental alloy was relatively small, i.e., the temperature range was 633–673 K, and the strain rate range was 0.001–0.1 s−1.

scholarly journals Hot deformation behavior and processing map of a novel dilute extruded Mg-Zn-Gd-Y-Nd alloy

2020 ◽  
Vol 01 ◽  
Author(s):  
Z. Abbasi ◽  
R. Ebrahimi
Keyword(s):  
High Temperatures ◽  
Hot Deformation ◽  
Processing Map ◽  
Material Model ◽  
Processing Parameters ◽  
Strain Rate Range ◽  
Parameters Optimization ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Strain

: The hot deformation response of a new dilute Mg alloy was investigated by means of a series of hot compression tests in the temperature and strain rate range of 375-450°C and 0.001-1 s-1 , respectively. The stress-strain behavior, microstructure evolution and processing parameters optimization were studied carefully. Micro-structural characterization studies conducted on a series of deformed samples using optical microscopy revealed that during hot deformation, the main restoration mechanism was dynamic recrystallization (DRX). In the final microstructure of the material, grain boundaries were thoroughly covered by layers of fine DRXed grains. Moreover, a strong twinning induced necklace structure was the most significant characteristic at high strain rates which was accompanied by smaller grain size in the domain material. Based on the measured stress-strain data, constitutive model was conducted on two regimes of low and high temperatures. Moreover, the processing map of the studied material was obtained and interpreted using dynamic material model (DMM). The processing map was built and divided into a feasible domain at high temperatures in the whole range of strain rates and two separated instable domains in the temperature range of 375 to 435°C at high and low strain rates of 1 and 0.001s-1 .

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