scholarly journals Hot Deformation Behavior and Processing Maps of Ti-6554 Alloy for Aviation Key Structural Parts

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 828
Author(s):  
Qi Liu ◽  
Zhaotian Wang ◽  
Hao Yang ◽  
Yongquan Ning
Keyword(s):  
Phase Transition ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Large Scale ◽  
Transition Point ◽  
Phase Transition Point ◽  
Aviation Industry ◽  
Processing Maps ◽  
Structural Parts

With the development of the aviation industry, the performance requirements of materials for aviation large-scale structural parts are getting higher and higher. Ti-6554 alloy is the material of choice for aviation large-scale structural parts, but its forming process window is narrow and its microstructure is sensitive to process parameters, which affects the performance of the alloy. By adjusting the existing hot deformation process, it is of great significance to improve the properties of the alloy. Hot compression tests of Ti-6554 alloy were carried out at temperatures of 715–840 °C and strain rates of 0.001–1 s−1. The results show that the flow stress and peak stress increased significantly with the increase of strain rate. At the same strain rate, the strain required for the stress to reach the peak point is smaller with the temperature increases. When the deformation temperature is below the phase transition point, the volume fraction and size of primary α phase gradually decrease with the increase of deformation temperature, while when the temperature is above the phase transition point, with the increase of deformation temperature, β grains grow up gradually, and the grain boundary bending effect is more obvious. The hyperbolic-sine Arrhenius constitutive equation was established. The correlation coefficient between experimental data and model calculated data reached 0.994. It indicates that the stress constitutive model proposed in this study can accurately reflect the stress characteristics of Ti-6554 alloy. Based on the dynamic material model, the processing maps of the alloy were established. The optimum hot deformation parameters range of the alloy was determined by analyzing the processing maps: the deformation temperature range of 800–830 °C, the strain rate range of 0.001–0.01 s−1. Through the analysis of the processing maps, the instability regions in the process of cross-phase forging can be effectively avoided, and the performance of the forging can be effectively improved.

scholarly journals Hot Deformation Characteristics—Constitutive Equation and Processing Maps—of 21-4N Heat-Resistant Steel

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 89 ◽  
Author(s):  
Yiming Li ◽  
Hongchao Ji ◽  
Wangda Li ◽  
Yaogang Li ◽  
Weichi Pei ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Strain Rate Range ◽  
Processing Maps ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Rate Range ◽  
Temperature Range ◽  
Heat Resistant

Abstract: The hot deformation behavior of 21-4N heat-resistant steel was studied by hot compression test in a deformation temperature range of 1000–1180 °C, a strain rate range of 0.01–10 s−1 and a deformation degree of 60%, and the stress-strain curves were obtained. The functional relationship between flow stress and process parameters (deformation degree, deformation temperature, strain rate, etc.) of 21-4N heat-resistant steel during hot deformation was explored, the constitutive equation of peak stress was established, and its accuracy was verified. Based on the dynamic material model, the energy dissipation maps and destabilization maps of 21-4N heat-resistant steel were established at strains of 0.2, 0.4 and 0.6, and processing maps were obtained by their superposition. Within the deformation temperature range of 1060~1120°C and a strain rate range of 0.01–0.1 s−1, there is a stable domain with the peak efficiency of about 0.5. The best hot working parameters (strain rate and deformation temperature) of 21-4N heat-resistant steel are determined by the stable and instable domain in the processing maps, which are in the deformation temperature range of 1120–1180 °C and the strain rate range of 0.01–10 s−1.

Analysis of Hot Deformation Dynamics of TC18 Titanium Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 878-884 ◽  
Author(s):  
Qing Rui Wang ◽  
Ai Xue Sha ◽  
Xing Wu Li ◽  
Li Jun Huang
Keyword(s):  
Titanium Alloy ◽  
Phase Transformation ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Temperature ◽  
Relationship Model ◽  
Deformation Dynamics ◽  
Deformation Mechanics ◽  
Versus Strain

The effect of strain rate and deformation temperature on flow stress of TC18 titanium alloy was studied through heat simulating tests in 760~960 with temperature interval and the strain rate interval in 0.01~10s-1. Relationship model of flow stress versus strain was established and hot deformation mechanics of TC18 titanium alloy was analyzed. The results show that the flow stress reduces obviously as the deformation temperature increases or the strain rate decreases. Dynamic recovery occurs at high strain rate above phase transformation point, while dynamic recrystallization occurs at low strain rate as well as at the temperature below phase transformation point.

scholarly journals Распространение поверхностной магнитоупругой волны в ферромагнетике в области ориентационного фазового перехода

2020 ◽  
Vol 62 (6) ◽  
pp. 851
Author(s):  
И.В. Мальцев ◽  
И.В. Бычков ◽  
Д.А. Кузьмин ◽  
В.Г. Шавров
Keyword(s):  
Phase Transition ◽  
Group Velocity ◽  
Yttrium Iron Garnet ◽  
Transition Point ◽  
Phase Transition Point ◽  
Yttrium Iron ◽  
Orientational Phase Transition ◽  
Velocity Changes ◽  
Iron Garnet ◽  
Magnetoelastic Surface

In this paper, we have studied the dependencies of group velocity and damping of magnetoelastic surface waves on the frequency at various external magnetic fields and propagation angles. The group velocity spikes occur at frequencies at which the damping peaks of the surface wave are detected. The behavior of a surface magnetoelastic wave in the vicinity of the orientational phase transition was also investigated. At the phase transition point, the group velocity changes by 1%. Dependences of the damping along the surface at various propagation angles point out on the nonreciprocal nature of the wave. All dependencies in this work were obtained using computer modeling. The parameters of the ferromagnet are taken typical for yttrium-iron garnet.

Dielectric lossbs near the phase transition point in DTGSel crystal

1989 ◽  
Vol 10 (6) ◽  
pp. 167-172
Author(s):  
S. A. Gridnev ◽  
B. N. Prasolov ◽  
O. V. Dybova
Keyword(s):  
Phase Transition ◽  
Transition Point ◽  
Phase Transition Point

Experimental and Numerical Investigations on Hot Deformation Behavior and Processing Maps for ASS 304 and ASS 316

2018 ◽  
Vol 37 (9-10) ◽  
pp. 873-888 ◽  
Author(s):  
Nitin Kotkunde ◽  
Hansoge Nitin Krishnamurthy ◽  
Swadesh Kumar Singh ◽  
Gangadhar Jella
Keyword(s):  
Experimental Data ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Constitutive Models ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Processing Maps ◽  
Hot Deformation Behavior ◽  
Statistical Measures

AbstractA thorough understanding of hot deformation behavior plays a vital role in determining process parameters of hot working processes. Firstly, uniaxial tensile tests have been performed in the temperature ranges of 150 °C–600 °C and strain rate ranges of 0.0001–0.01s−1 for analyzing the deformation behavior of ASS 304 and ASS 316. The phenomenological-based constitutive models namely modified Fields–Backofen (m-FB) and Khan–Huang–Liang (KHL) have been developed. The prediction capability of these models has been verified with experimental data using various statistical measures. Analysis of statistical measures revealed KHL model has good agreement with experimental flow stress data. Through the flow stresses behavior, the processing maps are established and analyzed according to the dynamic materials model (DMM). In the processing map, the variation of the efficiency of the power dissipation is plotted as a function of temperature and strain rate. The processing maps results have been validated with experimental data.

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