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 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.

scholarly journals Effect of Nitrogen Content on Hot Deformation Behavior and Grain Growth in Nuclear Grade 316LN Stainless Steel

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ming-wei Guo ◽  
Zhen-hua Wang ◽  
Ze-an Zhou ◽  
Shu-hua Sun ◽  
Wan-tang Fu
Keyword(s):  
Stainless Steel ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Grain Growth ◽  
Strain Rate Sensitivity ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Processing Maps ◽  
Hot Deformation Behavior

316LN stainless steel with 0.08%N (08N) and 0.17%N (17N) was compressed at 1073–1473 K and 0.001–10 s−1. The hot deformation behavior was investigated using stress-strain curve analysis, processing maps, and so forth. The microstructure was analyzed through electron backscatter diffraction analysis. Under most conditions, the deformation resistance of 17N was higher than that of 08N. This difference became more pronounced at lower temperatures. The strain rate sensitivity increased with increasing temperature for types of steel. In addition, the higher the N content, the higher the strain rate sensitivity. Hot deformation activation energy increased from 487 kJ/mol to 549 kJ/mol as N concentration was increased from 0.08% to 0.17%. The critical strain for initiation of dynamic recrystallization was lowered with increasing N content. In the processing maps, both power dissipation ratio and unstable region increased with increasing N concentration. In terms of microstructure evolution, N promoted dynamic recrystallization kinetic and decreased dynamic recrystallization grain size. The grain growth rate was lower in 17N than in 08N during heat treatment. Finally, it was found that N favored twin boundary formation.

Hot Deformation Behavior and Stability Criteria of WE54 Magnesium Alloy

2016 ◽  
Vol 879 ◽  
pp. 1618-1623 ◽  
Author(s):  
Ignacio Rieiro ◽  
Manuel Carsí ◽  
Oscar A. Ruano
Keyword(s):  
Magnesium Alloy ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Stability Criteria ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Logarithmic Curve ◽  
Efficiency Parameter

A precise description of the hot deformation behavior as well as determination of the stability conditions as influenced by temperature and strain rate is fundamental for the simulation of metal forming processes. In this work, a revision of various stability criteria of magnesium alloy WE54 is conducted. The study corresponds to own work and that of Lentz et al. and is based on compression tests at high temperature and high strain rates. Stability and processing maps were obtained using a variety of stability criteria, some based on the efficiency parameter η and others on the strain rate sensitivity parameter, m. This parameter is usually determined by fitting the curves strain rate, ε, versus stress, σ, by means of a potential equation named “power law” or by a polynomial of second or third degree, and calculating the slope of the logarithmic curve at each point using successive derivatives. This procedure is compared with one developed by us where all experimental points are fitted to a single hyperbolic sine equation of Garofalo type and then m and η are calculated for each ε and T using this equation. The maps obtained by one or the other method differ considerably. The predictions of these maps were contrasted with microstructural observations and conclusions on the deformation behavior of the alloy are reached.

Investigation of the Hot Deformation Behavior of an Al-Mg-Sc-Zr Alloy under Plane Strain Condition

2014 ◽  
Vol 611-612 ◽  
pp. 76-83 ◽  
Author(s):  
Johannes Taendl ◽  
Martina Dikovits ◽  
Cecilia Poletti
Keyword(s):  
Strain Rate ◽  
Plane Strain ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Hot Deformation Behavior ◽  
Flow Curves ◽  
Increasing Temperature ◽  
Zr Alloy

This study investigates the hot deformation behavior of a new Al-Mg-Sc-Zr alloy under plane strain conditions. Flow curves corrected for deformation heating were calculated for strain rates between 0.01 and 10s-1 in a temperature range of 200 to 400°C. To evaluate the deformation behavior, strain rate sensitivity as well as flow localization parameter maps were calculated for strains of 0.2, 0.4, and 0.6. In addition, microstructural investigations and hardness measurements were performed for selected samples. It was shown that the flow stress decreased with deacreasing strain rate and increasing temperature. The best formability was observed for high strain rates and low temperatures as well as for low strain rates and high temperatures. In these cases no flow instabilities were observed.

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

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.

Influence of temperature and strain rate on hot deformation behavior of Zr50Ti50 alloy in single β field

2016 ◽  
Vol 26 (8) ◽  
pp. 2086-2093 ◽  
Author(s):  
Yun-kai ZHOU ◽  
Zhi-hao FENG ◽  
Chao-qun XIA ◽  
Wen-chang LIU ◽  
Qin JING ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Hot Deformation Behavior ◽  
Influence Of Temperature

scholarly journals Hot Deformation Behavior and Microstructure Evolution of Cu–Ni–Co–Si Alloys

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2042 ◽  
Author(s):  
Feng Liu ◽  
Jimiao Ma ◽  
Lijun Peng ◽  
Guojie Huang ◽  
Wenjing Zhang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Strain Rate Range ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Hot Deformation Behavior ◽  
Deformation Activation Energy ◽  
The Matrix ◽  
Dynamic Recrystallization Behavior

The Cu-1.7Ni-1.4Co-0.65Si (wt%) alloy is hot compressed by a Gleeble-1500D machine under a temperature range of 760 to 970 °C and a strain rate range of 0.01 to 10 s−1. The flow stress increases with the extension of strain rate and decreases with the rising of deformation temperature. The dynamic recrystallization behavior happens during the hot compression deformation process. The hot deformation activation energy of the alloy can be calculated as 468.5 kJ/mol, and the high temperature deformation constitutive equation is confirmed. The hot processing map of the alloy is established on the basis of hot deformation behavior and hot working characteristics. With the optimal thermal deformation conditions of 940 to 970 °C and 0.01 to 10 s−1, the fine equiaxed grain and no holes are found in the matrix, which can provide significant guidance for hot deformation processing technology of Cu–Ni–Co–Si alloy.

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