Processing Map and Flow Localization of a TiAl/TiB2 XD Composite

1994 ◽  
Vol 350 ◽  
Author(s):  
D. Zhao ◽  
P. K. Chaudhury ◽  
M. Thirukkonda ◽  
J. J. Valencia
Keyword(s):  
Flow Behavior ◽  
Processing Condition ◽  
Microstructural Characterization ◽  
Parameter Analysis ◽  
Strain Rates ◽  
Compression Tests ◽  
Flow Localization ◽  
Dynamic Material Modeling ◽  
Particulate Reinforced ◽  
Stable Flow

AbstractIsothermal compression tests were conducted on a particulate reinforced Ti-44Al–3V+7.5v/o TiB2 composite produced by the XD® process over wide ranges of temperatures and strain rates, 1050 to 1300 C and 0.001 to 1.0 s-1, respectively. Flow localization parameter analysis was performed to analyze the flow behavior of the composite under various processing conditions, and the results were compared to those by dynamic material modeling. Microstructural characterization was also conducted to correlate the flow behavior with post-deformation microstructures. With combined information on flow behavior and microstructures, the processing condition for relatively stable flow and uniform microstructure was determined to be 1300 C and 0.01 to 0.1 s-1.

Workability of A Dual Phase Titanium Aluminide-TiB2 XdTM Composite

1992 ◽  
Vol 273 ◽  
Author(s):  
D. Zhao ◽  
K. G. Anand ◽  
J. J. Valencia ◽  
S. J. Wolff
Keyword(s):  
Titanium Aluminide ◽  
Flow Behavior ◽  
Element Model ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Compression Tests ◽  
Fem Model ◽  
Surface Cracking ◽  
Dynamic Material Modeling ◽  
Internal Fracture

ABSTRACTHigh temperature compression tests have been performed on a Ti-44a/o Al-3a/o V-7.5v/o TiB2XD composite over the temperature range 1000 to 1300°C and the strain rate range 10-3 to 10s-1. The workability of this material for metalforming processes was determined using both dynamic material modeling and workability testing approaches to cover both internal and surface cracking. At higher temperatures and strain rates internal fracture occurred in the material, while at lower temperatures and higher strain rates surface cracks occurred. Use of lower temperatures and strain rates inhibited internal instabilities and surface cracking in the composite. A finite element model (FEM) was developed to describe the stress and strain states during the deformation process. Mechanical flow behavior obtained from the compression tests was used as input to the model. A fracture criterion developed from Kuhn's surface crack equation was coupled with the FEM model to predict bulk formability in a forging process.

Constitutive Equation for 3104 Alloy at High Temperatures in Consideration of Strain

2016 ◽  
Vol 35 (6) ◽  
pp. 599-605 ◽  
Author(s):  
Fuqiang Zhen ◽  
Jianlin Sun ◽  
Jian Li
Keyword(s):  
Hot Deformation ◽  
Flow Behavior ◽  
Temperature Correction ◽  
Strain Rates ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Element Analysis ◽  
Hollomon Parameter ◽  
The Finite Element Analysis ◽  
Effects Of Temperature

AbstractThe flow behavior of 3104 aluminum alloy was investigated at temperatures ranging from 250°C to 500°C, and strain rates from 0.01 to 10 s−1 by isothermal compression tests. The true stress–strain curves were obtained from the measured load–stroke data and then modified by friction and temperature correction. The effects of temperature and strain rate on hot deformation behavior were represented by Zener–Hollomon parameter including Arrhenius term. Additionally, the influence of strain was incorporated considering the effect of strain on material constants. The derived constitution equation was applied to the finite element analysis of hot compression. The results show that the simulated force is consistent with the measured one. Consequently, the developed constitution equation is valid and feasible for numerical simulation in hot deformation process of 3104 alloy.

scholarly journals A Comparative Study on Johnson Cook, Modified Zerilli–Armstrong, and Arrhenius-Type Constitutive Models to Predict Compression Flow Behavior of SnSbCu Alloy

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1726 ◽  
Author(s):  
Tongyang Li ◽  
Bin Zhao ◽  
Xiqun Lu ◽  
Hanzhang Xu ◽  
Dequan Zou
Keyword(s):  
Experimental Data ◽  
Flow Behavior ◽  
Constitutive Models ◽  
Strain Range ◽  
Type Model ◽  
Strain Rates ◽  
Compression Tests ◽  
Predictive Values ◽  
Specific Strain ◽  
Optimum Model

The flow behavior of the SnSbCu alloy is studied experimentally by the compression tests in the range of the strain rates from 0.0001 to 0.1 s−1 and temperature from 293 to 413 K. Based on the experimental data, three constitutive models including the Johnson–Cook (J–C), modified Zerilli–Armstrong (Z–A), and Arrhenius-type (A-type) models are compared to find out an optimum model to describe the flow behavior of the SnSbCu alloy. The results show that the J–C model could predict the flow behavior of the SnSbCu alloy accurately only at some specific strain rates and temperature near the reference values. The modified Z–A and A-type constitutive models can give better fitting results than the J–C model. While, at high strains, the predictive values of the modified Z–A model have larger errors than those at low strains, which means this model has limitations at high strains. By comparison, the A-type model could predict the experimental results accurately at the whole strain range, which indicates that it is a more suitable choice to describe the flow behavior of the SnSbCu alloy in the focused range of strain rates and temperatures. The work is beneficial to solve the tribological problem of the bearing of the marine engine by integrating the accurate constitutive model into the corresponding numerical model.

Effect of Hot Deformation Parameters on Flow Behavior and Microstructure of Ti-6Al-4V-0.2O Alloy

2017 ◽  
Vol 898 ◽  
pp. 137-143
Author(s):  
Lin Xiang ◽  
Bin Tang ◽  
Hong Chao Kou ◽  
Jie Shao ◽  
Jin Shan Li
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Dynamic Recovery ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
Height Reduction ◽  
Deformation Parameters

Isothermal compression tests were conducted to investigate the effect of hot deformation parameters on flow behavior and microstructure of Ti-6Al-4V-0.2O alloy. The experimental results show that the strain rate and height reduction have little effect on the volume fraction of primary α at a deformation temperature of 860 ̊C. At a deformation temperature of 940 ̊C, the volume fraction of primary α at a high strain rate (10s-1) is about 10% less than that at low strain rates (0.01s-1~1s-1). It may be one of the reasons for the significantly discontinuous yielding phenomenon. Another reason is that the dislocation density decreased suddenly due to the dynamic recovery. With the increasing strain rate and the decreasing deformation temperature, the volume fraction of irregular secondary α increases and lamellar secondary α decreases. And with height reduction increasing, the irregular secondary α increases firstly and then tends to be steady because of dynamic recovery and recrystallization.

Compressive Flow Behavior of AZ61 Mg Alloy at Elevated Temperatures

2011 ◽  
Vol 311-313 ◽  
pp. 587-590
Author(s):  
Horng Yu Wu ◽  
Pin Hou Sun ◽  
Jie Chen Yan ◽  
Jing Hao Liao ◽  
Feng Jun Zhu ◽  
...  
Keyword(s):  
Structural Changes ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Mg Alloy ◽  
Strain Rates ◽  
Compression Tests ◽  
Flow Curves ◽  
Hollomon Parameter ◽  
Compressive Flow ◽  
Az61 Mg Alloy

The flow behavior and associated structural changes of an AZ61 Mg alloy were analyzed by using hot compression tests in the temperature and strain rate ranges of 250–400 °C and 0.001 to 1 s–1, respectively. The stress–strain curves exhibited the trend typical of materials in which deformation is recovery-controlled in the high Z regime (Z is the Zener–Hollomon parameter), while at low strain rates and high T, the flow curves exhibited a softening typical of recrystallization phenomena. Microstructure analysis has been performed to correlate the microstructure changes to the flow behaviors.

Critical assessment of CuZn39Pb2 processing maps

2020 ◽  
Vol 111 (5) ◽  
pp. 439-448
Author(s):  
Jing Yin ◽  
Shiqing Wu ◽  
Zhenlun Song ◽  
Cheng Xu ◽  
Qi Cui
Keyword(s):  
Continuous Casting ◽  
Process Parameters ◽  
Processing Map ◽  
Flow Behavior ◽  
Deformation Mechanisms ◽  
Instability Criterion ◽  
Strain Rates ◽  
Processing Maps ◽  
Compression Tests ◽  
Different Strains

Abstract Isothermal hot compression tests of the CuZn39Pb2 continuous casting bar were carried out at 650 - 750 °C and strain rates of 0.1 - 50 s-1. After the experimental data were obtained, processing maps were constructed and discussed on the basis of the Prasad, Murty and Malas instability criteria to critically evaluate the flow behavior of the CuZn39Pb2 continuous casting bar. The microstructure suggested that the processing map based on the Murty instability criterion was suitable for optimizing the process parameters of the CuZn39Pb2. The relationships between the characteristics of processing maps and the deformation mechanisms under different strains were analyzed on the basis of Murty instability criterion. Considering the theoretical analysis results and energy consumption economy, 690 °C ≤ T ≤ 720 °C with 1 s-1 ≤ έ ≤ 3 s-1 are the best process parameters for CuZn39Pb2 forging.

Constitutive Analysis to Predict Elevated Temperature Flow Behavior of TC21 Titanium Alloy

2013 ◽  
Vol 811 ◽  
pp. 152-156
Author(s):  
Li Bin Jia ◽  
Lin Li ◽  
Yi Ru
Keyword(s):  
Titanium Alloy ◽  
Constitutive Equation ◽  
Flow Behavior ◽  
Strain Rates ◽  
Hot Workability ◽  
Compression Tests ◽  
Absolute Relative Error ◽  
Constitutive Analysis ◽  
Hyperbolic Sine ◽  
Average Absolute Relative Error

In order to study the hot workability of TC21 titanium alloy, isothermal hot compression tests were conducted in the temperatures range of 1123~1203K and strain rates range of 0.01~10s-1. The influence of strain was incorporated in hyperbolic sine constitutive equation by considering the effect of strain on material constants. Correlation coefficient (R) and average absolute relative error (AARE) were introduced to verify the validity of the developed hyperbolic sine constitutive equation. The values of R and AARE were determined to be 0.9891 and 7.753% respectively, which indicated that the developed hyperbolic sine constitutive equation considering strain compensation could precisely predict the flow behavior of TC21 titanium alloy throughout the entire range of temperatures and strain rates.

Work Hardening and Flow Softening of γ-TiAl Containing Ni

2004 ◽  
Vol 449-452 ◽  
pp. 833-836 ◽  
Author(s):  
Jian Hui Zhang ◽  
Kenong Xia ◽  
Erik Strom ◽  
Zeng Yong Zhong ◽  
Chang Hai Li
Keyword(s):  
Work Hardening ◽  
Flow Behavior ◽  
Peak Stress ◽  
True Stress ◽  
Flow Softening ◽  
Strain Rates ◽  
Isothermal Compression ◽  
Compression Tests ◽  
Steady State Flow ◽  
Ni Addition

This paper presents the true stress - strain curves and data analyses of a Ni-containing TiAl and its reference alloy based on the isothermal compression tests at 1000°C and 0.01 - 1.0s-1strain rates. The results show that the minor Ni addition makes the flow softening coming sooner and therefore significantly lowers the peak stress. Those effects, in addition with a better balance between the work hardening and flow softening during hot deformation, improve the steady state flow behavior of TiAl. The Ni-influence mechanisms are also suggested based on the TEM observation of dislocation configurations and lamellar breakdown during the deformation.

Constitutive Equation of Mg-13Al-3Ca-3Zn-1Nd-0.2Mn Magnesium Alloy

2014 ◽  
Vol 968 ◽  
pp. 3-6
Author(s):  
Wei Chen ◽  
Gang Chen ◽  
Jing Zhai ◽  
Li Ma
Keyword(s):  
Activation Energy ◽  
Magnesium Alloy ◽  
Constitutive Equation ◽  
Temperature Regime ◽  
Constitutive Equations ◽  
Flow Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
Related Material ◽  
Base Analysis

The constitutive equations may properly describe the flow behavior of the materials. In the present study, the constitutive equation of Mg-13Al-3Ca-3Zn-1Nd-0.2Mn alloy were investigated using hot compression tests at the temperatures range of 200, 250, 300, 350 and 400°Cwith the constant strain rates of 0.001, 0.01, 0.1, 1 and 10s-1.The hot working constitutive base analysis has been conducted on the experimental alloy. The related material constants n, α and β, as well as the activation energy Q for each temperature regime have been determined. At last, the constitutive equations is given.

scholarly journals A Modified Constitutive Model for the Description of the Flow Behavior of the Ti-10V-2Fe-3Al Alloy during Hot Plastic Deformation

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 844 ◽  
Author(s):  
Wang ◽  
Shen ◽  
Zhang ◽  
Ning
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
Flow Curves ◽  
Deformation Parameters ◽  
Predicted Values

The hot deformation behavior of the aerospace Ti-10-2-3 alloy was investigated by isothermal compression tests at temperatures of 740 to 820 °C and strain rates of 0.0005 to 10 s−1. The results show that the studied alloy is extremely sensitive to deformation parameters, like the temperature and strain rate. The temperature mainly affects the magnitude of flow stress at larger strains, while the strain rate not only affects the value of flow stress but also the shape of the flow curves. At low strain rates, the flow stress increases with strain, followed by a broad peak and then remains almost constant. At high strain rates, the flow curves exhibit a hardening to a sharp peak at small strains, followed by a rapid dropping to a plateau caused by dynamic softening. In order to describe such flow behavior, a constitutive model considering the effect of deformation parameters was developed as an extension of an existing constitutive model. The modified constitutive model (MC) was obtained based on the original constitutive model (OC) by introducing a new parameter to compensate for the error between the experimental data and predicted values. Compared to the original model, the developed model provides a better description of the flow behavior of Ti-10-2-3 alloy at elevated temperatures over the specified deformation domain.

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