scholarly journals Hot Deformation Behavior and Microstructural Evolution of PM Ti43Al9V0.3Y with Fine Equiaxed γ and B2 Grain Microstructure

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 896
Author(s):  
Dongdong Zhang ◽  
Yuyong Chen ◽  
Guoqing Zhang ◽  
Na Liu ◽  
Fantao Kong ◽  
...  
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Hot Working ◽  
Boundary Slip ◽  
Hot Deformation Behavior ◽  
Strain And Strain Rate ◽  
Working Parameters ◽  
Temperature Strain

The hot deformation behavior and microstructure evolution of powder metallurgy (PM) Ti43Al9V0.3Y alloy with fine equiaxed γ and B2 grains were investigated using uniaxial hot compression. Its stress exponent and activation energy were 2.78 and 295.86 kJ/mol, respectively. The efficiency of power dissipation and instability parameters were evaluated, and processing maps at 50% and 80% strains were developed. It is demonstrated that the microstructure evolution was dependent on the temperature, strain, and strain rate. Both temperature and strain increases led to a decrease in the γ phase. Moreover, dynamic recrystallization (DRX) and grain boundary slip both played important roles in deformation. Reasonable parameters for secondary hot working included temperatures above 1100 °C but below 1200 °C with a strain rate of less than 1 s−1 at 80% strain. Suitable hot working parameters at 50% strain were 1150–1200 °C/≤1 s−1 and 1000–1200 °C/≤0.05 s−1.

Hot Deformation Behavior and Microstructure Evolution of a DC Cast Hypereutectic Al-Si Alloy

2012 ◽  
Vol 151 ◽  
pp. 332-336
Author(s):  
Ke Zhun He ◽  
Fu Xiao Yu ◽  
Da Zhi Zhao ◽  
Liang Zuo
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Peak Stress ◽  
Strain Rate Range ◽  
Hot Deformation Behavior ◽  
Strong Function ◽  
Primary Si

The hot deformation behavior and microstructure evolution of a DC cast hypereutectic Al-Si alloy was studied in the temperature range of 400-500 °C and strain rate range of 0.001-1 s-1. The results show that the as-cast microstructure of the alloy consists of polygonal primary Si particles and α-aluminum dendritic halos with Al-Si eutectics and intermetallic compounds segregated into the interdendritic regions. The flow stress of the alloy is a strong function of temperature and strain rate, and the peak stress is increased with the decrease of deformation temperature and the increase of strain rate. All the true stress-true stain curves in the experiments exhibit dynamic softening. The fracture frequency of primary Si particle is decreased with the increase of deformation temperature and the decrease of strain rate. The dynamic flow softening is mainly as a result of dynamic recrystallization.

scholarly journals Hot deformation behavior of 60NiTi shape-memory alloy fabricated by hot isostatic pressing

2022 ◽  
Author(s):  
Mei-ling Li ◽  
Wen-jin Gao ◽  
Ying-hao Zhou
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Work Hardening ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Dynamic Equilibrium ◽  
High Stress ◽  
Cylindrical Sample ◽  
Hot Working ◽  
Hot Deformation Behavior

Abstract The 60NiTi (Ni60wt%–Ti40wt%) intermetallic is a hard-to-process material. Understanding of hot deformation behavior is crucial for the hot working of 60NiTi. This work studied hot deformation behavior and corresponding microstructure of the hot isostatic pressed 60NiTi in the temperature range of 900 °C–1050 °C and at strain rates of 0.1, 0.01, and 0.001 s-1 through a hot compression test. The flow stress and microstructure were susceptible to the hot deformation parameters. The flow stress decreased with the increase in deformation temperature and decrease in strain rate. Work hardening occurred at a small strain, then followed by softening; finally, near-dynamic equilibrium was achieved between work hardening and softening. A constitutive equation was developed to describe the effects of strain rate and temperature on flow stress. Simulation of hot deformation via the finite element method revealed the workpiece’s inhomogeneous deformation. The deformation occurred mainly in the center area of the cylindrical sample, resulting in high stress and strain concentrations in this region and causing the equiaxial grains to be compressed into prolate grains. This work can provide guidance for the hot working, such as forging and hot rolling, of 60NiTi.

scholarly journals Comparative Study of Hot Deformation Behavior and Microstructure Evolution of As-Cast and Extruded WE43 Magnesium Alloy

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 429
Author(s):  
Yuehua Kang ◽  
Zhenghua Huang ◽  
Hu Zhao ◽  
Chunlei Gan ◽  
Nan Zhou ◽  
...  
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
True Strain ◽  
Fiber Texture ◽  
Grain Structure ◽  
Hot Deformation Behavior ◽  
Fine Grain ◽  
We43 Alloy

Under compressive testing at 400 °C and a strain rate range of 0.05–5 s−1, the hot deformation behavior and microstructure evolution of an as-cast (AC), as-extruded (with a bimodal grain structure (named as Ex-1) or a relatively uniform fine grain structure (Ex-2)) WE43 alloy have been investigated and compared. The results indicate that the AC sample exhibits the highest peak stress, while the Ex-2 sample has the lowest value. Within the AC material, fine grains were firstly formed along the pancake-like deformed grains (as a necklace structure). The necklace structure was also formed within the Ex-1 and Ex-2 materials at high strain rates of 0.5 and 5 s−1. However, a lamellar structure that the coarse elongated grains divided by parallel boundaries was formed within the Ex-1 material. A relatively more homogeneous fine grain structure is achieved after a true strain of 1.0 within the Ex-2 material at a low strain rate of 0.05 s−1. In addition, a discontinuous dynamic recrystallization mechanism by grain boundary bulging is found to occur. After a true strain of 1.2, a (0001) fiber texture, a typical rare earth (RE) texture, and a relatively random texture are formed within the AC, Ex-1, and Ex-2 WE43 alloy material, respectively.

Study on Hot Deformation Behavior and Constitutive Relation of Cr-77.5Nb Alloy

2014 ◽  
Vol 898 ◽  
pp. 72-75
Author(s):  
Wen Wen Han ◽  
Shi Qiang Lu ◽  
Li Ping Deng
Keyword(s):  
Strain Rate ◽  
Constitutive Relation ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Stepwise Regression ◽  
Constant Strain Rate ◽  
Isothermal Compression ◽  
Hot Deformation Behavior ◽  
Deformation Parameters ◽  
Temperature Strain

Isothermal compression test at constant strain rate for Cr-77.5Nb alloy were performed on Gleeble simulator with conditions of deformation temperature from 800 to 1200°C and strain rate from 0.001s-1to 0.1s-1. The influence of deformation parameters including temperature, strain rate and strain related with flow stress during hot deformation were investigated and the constitutive relation of Cr-77.5Nb alloy was established by stepwise regression method. The result of error analysis shows that the constitutive relation established has high accuracy and can well characterize the hot deformation behavior of this alloy.

scholarly journals Hot Deformation Behavior and Microstructure Evolution of a TiBw/Near α-Ti Composite with Fine Matrix Microstructure

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 481 ◽  
Author(s):  
Zhang ◽  
Lian ◽  
Chen ◽  
Sun ◽  
Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Matrix Microstructure

The hot deformation behavior and microstructure evolution of a 7.5 vol% TiBw/near α-Ti composite with fine matrix microstructure were investigated under the deformation conditions in a temperature range of 800–950 °C and strain rate range of 0.001–1 s−1 using plane strain compression tests. The flow stress curves show different characteristics according to the various deformation conditions. At a higher strain rate (1 s−1), the flow stress of the composite continuously increases until a peak value is reached. The activation energy is 410.40 kJ/mol, much lower than the activation energy of as-sintered or as-forged composites. The decreased activation energy is ascribed to the breaking of the TiBw reinforcement during the multi-directional forging and the resultant fine matrix microstructure. Refined reinforcement and refined matrix microstructure significantly improve the hot deformation ability of the composite. The deformation conditions determine the morphology and fraction of α and β phases. At 800–900 °C and 0.01 s−1 the matrix α grains are much refined due to the continuous dynamic recrystallization (CDRX). The processing map is constructed based on the hot deformation behavior and microstructure evolution. The optimal hot processing window is determined to be 800–950 °C/0.001–0.01 s−1, which lead to CDRX of primary α grains or dynamic recovery (DRV) and dynamic recrystallization (DRX) of β phase.

Hot Deformation Behavior and Microstructure Evolution of GH625 Superalloy Tube during Extrusion Process

2011 ◽  
Vol 291-294 ◽  
pp. 640-644
Author(s):  
Qing Miao Guo ◽  
De Fu Li ◽  
Sheng Li Guo ◽  
Guo Ling Xie
Keyword(s):  
Strain Rate ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Deformation Temperature ◽  
Flow Behavior ◽  
Outer Wall ◽  
Extrusion Process ◽  
Compression Tests ◽  
Hot Deformation Behavior

Flow behavior and microstructures of GH625 superalloy were investigated by hot compression tests. Then the GH625 superalloy tube was hot extruded according to the hot deformation behavior, and the microstructures of different position of extruded tube was also analyzed. The results show that the actual deformation temperature of the specimen deformed at a strain rate of 10.0s-1 is higher than the preset temperature, resulting in a deformation thermal effect. Thus, the microstructure evolution of GH625 superalloy is controlled both by the strain rate and deformation temperature. It is also found that the GH625 superalloy tube can be successfully fabricated with a stable extrusion speed of 40 mm·s-1, extrusion ratio of 4.1 and preheating temperature of 1200°C. The microstructure of extruded tube was obviously fined due to the occurrence of dynamic recrystallization(DRX). Different degrees of DRX were observed in outer wall, center and inner wall of the tube, which is similar to that in the head, middle and tail of the tube. An extruded tube containing fully DRX grains can be obtained by cutting the head and tail of the tube, and machining a small amount of the inner wall.

scholarly journals Hot deformation behavior and related microstructure evolution in Au−Sn eutectic multilayers

2021 ◽  
Vol 31 (6) ◽  
pp. 1700-1716
Author(s):  
Yong MAO ◽  
Dan-li ZHU ◽  
Jun-jie HE ◽  
Chao DENG ◽  
Ying-jie SUN ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Hot Deformation Behavior

Effect of temperature and strain rate on hot deformation behavior and microstructure of Al-Cu-Li alloy

2017 ◽  
Vol 723 ◽  
pp. 548-558 ◽  
Author(s):  
Niraj Nayan ◽  
S.V.S. Narayana Murty ◽  
Sumit Chhangani ◽  
Aditya Prakash ◽  
M.J.N.V. Prasad ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Effect Of Temperature ◽  
Hot Deformation Behavior
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