scholarly journals Numerical and Experimental Study on Microstructure Evolution of Ti-6Al-4V Alloy Shaft Perform in Cross-Wedge Rolling Process

2021 ◽  
Author(s):  
Jiayao Yuan ◽  
Xing Chen ◽  
Zhilong Zhao ◽  
Baoshou Sun ◽  
Xuedao Shu
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Phase Region ◽  
Rolling Temperature ◽  
Structure Evolution ◽  
Cross Wedge Rolling ◽  
Two Phase ◽  
Rotating Speed ◽  
Area Reduction ◽  
Average Grain Size

Abstract To seek a fundamental understanding for further improving the Ti-6Al-4V alloy utilization of Cross-Wedge Rolling (CWR) and the comprehensive mechanical properties of shaft parts, the effect of the CWR processing parameters on the microstructure evolution of Ti-6Al-4V alloy shaft preform is studied in this paper. An Arrhenius-type microstructure structure evolution model was employed and implemented into the finite element software DEFORM-3D. The average grain size and dynamic re-crystallization volume fraction distribution in the α+β two-phase region and the β single phase region under different rolling temperature, roller rotating speed and area reduction were analyzed, respectively. It is finding that the area reduction, rolling temperature and roller rotating speed significantly affect the microstructure evolution of Ti-6Al-4V alloy. Meanwhile, the corresponding CWR and Metallographic experiments were conducted to verify the reliability of the FE simulation results. Results showed that the agreement of the process parameters effect on dynamic recrystallization in the α+β two-phase region between simulation and experimental is reasonably good. The difference in average grain size in the β phase region between simulation and experimental is ranged from 5.77% to 18.56%. In addition, the evenly distributed microstructure can be found as the area reduction of 50%, rolling temperature of 950℃ and the speed of 5 r⋅min−1 were employed. After rolling under optimized processing conditions, the tensile strength of Ti-6Al-4V alloy shaft preform increased by 18.57% and the plasticity enhanced significantly due to smaller grain size and bi-model microstructure obtained.

The Effect of Rolling Temperature on Grain Size and Toughness in Hot Rolled Q345E H-Beam Steel

2018 ◽  
Vol 279 ◽  
pp. 26-29
Author(s):  
Li Ping Sun ◽  
Guo Hui Zhu ◽  
Jun Xing ◽  
Qi Wei Chen
Keyword(s):  
Grain Size ◽  
Rolling Temperature ◽  
Experimental Results ◽  
Average Grain Size ◽  
H Beam ◽  
Rolling Temperatures ◽  
Hot Rolled

The effect of enter rolling temperatures on the grain size and toughness was investigated in Q345E H-beam steels. The experimental results shown that the grain size exhibited a complicated phenomenon with rolling temperature instead of refining as the temperature decreased as expected. It would be interpreted by the behaviors of deformation and recrystallization in austenite during rolling. The toughness is not only depended on the average grain size but also on the distribution of grain size as well as morphology of pearlite. The toughness would be decreased by the mixed grain size.

scholarly journals Enhanced Mechanical Properties of Mg-6Sn-3Al-1Zn Alloy with Bimodal Grain Size Disturbed in the Microstructure Uniformly through Changing the Rolling Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Fuan Wei ◽  
Jinhui Wang ◽  
Ping Li ◽  
Bo Shi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Strength ◽  
Volume Fraction ◽  
Rolling Temperature ◽  
Average Grain Size ◽  
Small Grains ◽  
Mg2sn Phase ◽  
Average Size ◽  
Bimodal Grain Size

The mechanical properties of Mg-6Sn-3Al-1Zn alloy were enhanced with bimodal grain size disturbed in the microstructure uniformly; the Mg-6Sn-3Al-1Zn alloys were rolled with 60% thickness reduction at different rolling temperatures. The results have shown that the Mg-6Sn-3Al-1Zn alloys are composed of Mg2Sn phase and α-Mg matrix phase. When the rolling temperature was less than or equal to 400°C, with the rolling temperature increasing, the average size and volume fraction of Mg2Sn phase and the average grain size of small grains remained unchanged, the average grain size of large grains decreased, the volume fraction of small grains increased, and the yield strength of the alloy increased. When the rolling temperature reached 450°C, the average size and volume fraction of Mg2Sn phase and the average grain size of large grains increased, and the volume fraction of small grains and the yield strength of the alloy decreased. The elongation increased with the rolling temperature increasing, but the change trend of hardness was just opposite. When the alloy was rolled at 400°C, the average sizes of small grains, large grains, and Mg2Sn phases were 3.66 μm, 9.24 μm, and 19.5 μm, respectively. The volume fractions of small grains, large grains, and Mg2Sn phases were 18.6%, 77.6%, and 3.8%, respectively. And the tensile properties reached the optimum; for example, the tensile strength, yield strength, elongation, and Vickers hardness were 361 MPa, 289.5 MPa, 20.5%, and 76.3 HV, respectively.

Microstructure evolution during deformation of a near-α titanium alloy with different initial structures in the two-phase region

2009 ◽  
Vol 61 (4) ◽  
pp. 419-422 ◽  
Author(s):  
Behrang Poorganji ◽  
Makoto Yamaguchi ◽  
Yoshio Itsumi ◽  
Katsushi Matsumoto ◽  
Tomofumi Tanaka ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Microstructure Evolution ◽  
Phase Region ◽  
Two Phase

Application of Radial Forging and Remelting Treatment to Prepare Semi-Solid Billet of AlMg0.7Si Alloy

2016 ◽  
Vol 256 ◽  
pp. 257-262 ◽  
Author(s):  
Yong Fei Wang ◽  
Sheng Dun Zhao ◽  
Chen Yang Zhang
Keyword(s):  
Grain Size ◽  
Partial Melting ◽  
Starting Material ◽  
Main Mechanism ◽  
Solid Alloy ◽  
Radial Forging ◽  
Area Reduction ◽  
Average Grain Size ◽  
Semi Solid ◽  
Deformation Recovery

Semi-solid AlMg0.7Si alloy was prepared by recrystallization and partial melting (RAP) method which including radial forging (RF) and remelting process. RF was carried out with different area reduction ratios (ARRs) to accumulate strains, effect of ARR and remelting time on microstructure was studied, mechanism of RAP preparing semi-solid AlMg0.7Si alloy was summarized. Results show that, compared with the large and irregular solid grains form remelting of starting material, solid grains of semi-solid alloy prepared by RAP are fine and globular, and the optimum microstructure can be obtained when alloy with 80% ARR is remelted at 630 °C for 10 min. With the increase of ARR, the solid grains are smaller and rounder. With the increase of remelting time, the average grain size is increased, and the spheroidization degree of solid grain is gradually improved. The main mechanism consists of pre-deformation, recovery and recrystallization, grains fragmentation, grains spheroidization and coarsening.

Submicrocrystalline Structure Formation in Ti and Ti-64 Alloy by Warm “abc” Deformation

2007 ◽  
Vol 551-552 ◽  
pp. 183-188 ◽  
Author(s):  
Sergey V. Zherebtsov ◽  
Sergey Mironov ◽  
Gennady A. Salishchev
Keyword(s):  
Grain Size ◽  
Titanium Alloy ◽  
Steady State ◽  
Mechanical Behavior ◽  
Structure Formation ◽  
Microstructure Evolution ◽  
Superplastic Flow ◽  
Steady State Flow ◽  
Two Phase ◽  
State Flow

Mechanical behavior and microstructure evolution of Ti and Ti-64 titanium alloy during warm “abc” deformation has been studied. The “abc” deformation was consisted of successive compression of a sample along three orthogonal directions. Mechanical behavior of each material was described by set of successive σ-ε curves combined into cumulative σ-Σε curve. Microstructure of Ti was found to be refined to a grain size of about 0.4 μm due to formation of deformation-induced boundaries within initial grains. Although a stage like steady state flow was observed at the cumulative σ-Σε curve such mechanical behavior was hardly associated with superplastic flow. In two-phase Ti-64 alloy the structure was found to be refined to a grain size of about 0.4 μm after warm “abc” deformation due to globularization α- and β-particles following breaking down of α-lamellar and β- layers. Microstructure refinement of the alloy was associated with softening and superplastic flow.

Simulation of the Effect of Initial Grain Size of Matrix on Microstructure Evolution in Nano-Composite Ceramic Tool Material

2010 ◽  
Vol 431-432 ◽  
pp. 527-530
Author(s):  
Hong Mei Cheng ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Y. Li
Keyword(s):  
Grain Size ◽  
Microstructure Evolution ◽  
Tool Material ◽  
Composite Ceramic ◽  
Ceramic Materials ◽  
Sintering Process ◽  
Initial Matrix ◽  
Two Phase ◽  
Nano Composite ◽  
Set Up

A new Monte Carlo Potts′ model for the sintering process of two-phase nano-composite ceramic materials with various grain size of initial matrix is set up. The grain growth process is successfully investigated assuming the green body is completely dense. The effect of the initial matrix grain size on microstructure evolution is observed and discussed quantitatively.

Simulation of Recrystallization Behavior and Austenite Grain Size Evolution during Hot Deformation of Low Carbon Steel Using the Flow Stress

2011 ◽  
Vol 337 ◽  
pp. 178-183 ◽  
Author(s):  
Jian Wang ◽  
Hong Xiao ◽  
Hong Biao Xie ◽  
Xiu Mei Xu
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Dislocation Density ◽  
Microstructure Evolution ◽  
Hot Deformation ◽  
Process Model ◽  
Model Parameters ◽  
Flow Curves ◽  
Austenite Grain Size ◽  
Average Grain Size

Microstructure evolution can cause changes in dislocation density during hot plastic formation of metals and greatly influence the shape of flow curves. Recrystallization kinetics and average grain size were simulated by the coupled flow stress model describing dislocation development and microstructure evolution. The model for microstructure evolution considered different kinds of recrystallization in the same process rooted from nucleation and grain growth. Flow stress was calculated from the average dislocation density determined by the dislocation density model, which took into account hardening and recovery during the hot deformation process. Model parameters were defined by inverse analysis of flow curves obtained from hot compression tests and were completed through solving a nonlinear least-squares problem with constraints using optimization methods. Finally, the results obtained by the proposed model were compared with experimental results.

Effect of Two-Phase Region Quenching Temperature on Microstructure Evolution and Microhardness of HSLA100 Steel

2012 ◽  
Vol 602-604 ◽  
pp. 380-384
Author(s):  
X. Yan ◽  
G.F. Zhou ◽  
C.M. Zhu ◽  
J.S. Guan
Keyword(s):  
Microstructure Evolution ◽  
Volume Fraction ◽  
High Strength ◽  
Phase Region ◽  
Two Phase ◽  
Quenching Temperature ◽  
Island Structure ◽  
Transmission Electron ◽  
Evolution Characteristics ◽  
Lath Bainite

The microstructure evolution characteristics and those effects on microhardness of HSLA (high strength low alloy) 100 steel secondary quenched in the two-phase region were investigated. The results show that the mixed microstructure of ferrite and the M-A（mastenite-austenite）islands can be obtained in the intercritical quenching region. A small amount of island structure distributing along the lath ferrite quenched at 700°C is observed by transmission electron microscope (TEM). With the quenching temperature increasing, the island structure increases in quantity and coarsens in shape, at the same time, the ferrite gradually transform from single lath morphology to polygonal shape with the dislocation density lowing. When quenched at 820°C, the microstructure reverts to lath bainite. There is a good correlation between Vickers hardness value and the volume fraction of martensite or bainite HSLA100 steel quenched in the two-phase region. The microhardness value of the steel continually increase from 240HV to 320HV quenched at the range of 700°C to 820°C, and then keep a very small fluctuation around 320HV when the temperature exceeds to 820°C.

scholarly journals Deformation and Phase Transformation of Disorder α Phase at (α+γ) two Phase Region in high Nb Containing TiAl alloy

2021 ◽  
Author(s):  
Haitao Zhou ◽  
Fantao Kong ◽  
Yanbo Wang ◽  
Xiangwu Hou ◽  
Ning Cui ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Microstructural Evolution ◽  
Microstructure Evolution ◽  
Tial Alloy ◽  
Temperature Drop ◽  
Alpha Phase ◽  
Phase Region ◽  
Two Phase ◽  
Α Phase ◽  
Assisted Decomposition

In this paper, the deformation and phase transformation of disorder α phase at (α + γ) two phase region in as-forged Ti-44Al-8Nb-(W, B, Y) alloy are investigated by hot compression and hot packed rolling. Detailed microstructural evolution demonstrates that the as-deformed microstructure is significantly affected by deformation conditions. The mircrostructure differences are mainly due to temperature drop and strain rate. The evolution of α lamelae into α grains is detailed descripted. Moreover, the disorder α lamellae can also be decomposed into some new α grains by the assisted decomposition mechanism of γ grains. Microstructure evolution model of current TiAl alloy at 1250 °C during hot rolling is built.

Forming Technology and Microstructure Distribution of Automobile Oil Pump Shaft by Extruded Cross Wedge Rolling

2019 ◽  
Author(s):  
Xue-Dao Shu ◽  
Tai-Zhu Chen ◽  
Ying Chang ◽  
Ying Zhu ◽  
Wen-Wei Gong
Keyword(s):  
Grain Size ◽  
Fem Simulation ◽  
Grain Structure ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Oil Pump ◽  
Average Grain Size ◽  
Pump Shaft ◽  
Utilization Ratio ◽  
Material Utilization

Abstract In order to improve the material utilization ratio of automobile oil pump shaft, the extrusion wedge cross rolling process was developed to form automobile oil pump shaft, the results show that the volume of the blank head produced by extrusion cross wedge rolling is reduced by about 75% compared with that produced by traditional cross wedge rolling, and the material utilization ratio can be increased to about 95%. The microstructure distribution of automobile oil pump shaft formed by this process was studied systematically by fem simulation and experiment, get the forming process can make the grain size of oil pump shaft rolling parts refine continuously, and finally obtain fine and uniform grain structure. The average grain size measured by the experiment is in good agreement with the simulation results. The research results lay a theoretical foundation for reducing oil pump cost and improving life.

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