Uniaxial Cyclic Deformation Behavior of 6061Al Alloy and its Time-Dependence at Room and High Temperatures

2007 ◽  
Vol 345-346 ◽  
pp. 9-12 ◽  
Author(s):  
Guo Zheng Kang ◽  
Yu Jie Liu ◽  
Jun Ding
Keyword(s):  
High Temperatures ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Hold Time ◽  
Cyclic Softening ◽  
Loading Rates ◽  
Ratcheting Strain ◽  
Deformation Behaviors ◽  
Cyclic Straining ◽  
Stressing Rate

The cyclic deformation behavior of 6061Al-T6 alloy was studied by uniaxial cyclic straining or stressing tests at room and high temperatures. The cyclic softening/hardening feature of the material and its effect on the uniaxial ratcheting occurred under asymmetrical cyclic stressing were discussed. The cyclic deformation behaviors of the material presented at various loading rates and with certain peak and/or valley strain or stress holds were addressed. It is concluded from the experimental results that 6061Al-T6 alloy presents slightly cyclic softening feature, and its cyclic deformation is time-dependent even at room temperature. The ratcheting strain produced at lower stressing rate and with longer hold-time is apparently larger than that at higher stressing rate and with fewer hold-time. Some significant conclusions useful to construct the constitutive model to describe such cyclic deformation behaviors are obtained.

Uniaxial Cyclic Deformation Behaviors of 42CrMo Steel with Different Heat-Treatments

2007 ◽  
Vol 353-358 ◽  
pp. 555-558 ◽  
Author(s):  
Guo Zheng Kang ◽  
Zhao Li ◽  
Yu Jie Liu
Keyword(s):  
Strain Rate ◽  
Cyclic Deformation ◽  
Room Temperature ◽  
Annealed Sample ◽  
Cyclic Softening ◽  
Heat Treatments ◽  
Ratcheting Strain ◽  
42Crmo Steel ◽  
Deformation Behaviors ◽  
Cyclic Straining

The cyclic deformation behaviors of 42CrMo steel with different heat treatments were observed by uniaxial cyclic straining and stressing tests at room temperature. The cyclic softening/ hardening features of the tempered or annealed 42CrMo steel and their effects on the uniaxial ratcheting produced in asymmetrical cyclic stressing were discussed. It is concluded that the tempered 42CrMo steel shows significantly cyclic softening feature, but the annealed one is cyclic stabilizing. Different ratcheting behaviors are also observed. For the tempered 42CrMo steel, a special tertiary ratcheting behavior is observed and the previous cyclic straining greatly accelerates the evolution of ratcheting strain in subsequent cyclic stressing. In contrast, the annealed sample presents a stabilized ratcheting with nearly constant ratcheting strain rate after certain cycles, and the previous cyclic straining slightly influences the ratcheting in subsequent cyclic stressing.

Uniaxial and Multiaxial Cyclic Deformation Behaviors of SiCp/6061Al Alloy Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1247-1250 ◽  
Author(s):  
Guo Zheng Kang ◽  
Yu Jie Liu
Keyword(s):  
Cyclic Deformation ◽  
Room Temperature ◽  
Cyclic Softening ◽  
Mean Stress ◽  
Ratcheting Strain ◽  
The Matrix ◽  
Deformation Behaviors ◽  
Sic Particulates ◽  
Cyclic Straining ◽  
Particulate Volume

The uniaxial/multiaxial cyclic deformation behaviors of SiCp/6061Al alloy composites with various particulate volume fractions were studied by uniaxial and multiaxial cyclic straining or stressing tests at room temperature. The cyclic softening/hardening features and ratcheting behaviors of T6-treated composites and un-reinforced matrix were discussed in different loading conditions. It is shown that the ratcheting also occurs in the composites under uniaxial and multiaxial asymmetrical cyclic stressing, and the ratcheting strain increases with stress amplitude and mean stress; however, the addition of SiC particulates into the matrix increases the resistance of the composite to ratcheting. The ratcheting depends greatly on the shapes of loading paths and mainly occurs in the direction of non-zero mean stress.

Strain-Rate-Dependent Deformation Behavior of Carbon-Black-Filled Rubber under Monotonic and Cyclic Straining

2007 ◽  
Vol 340-341 ◽  
pp. 1017-1024 ◽  
Author(s):  
Yoshihiro Tomita ◽  
K. Azuma ◽  
M. Naito
Keyword(s):  
Strain Rate ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Filled Rubber ◽  
Deformation Behaviors ◽  
Deformation Processes ◽  
The Individual ◽  
Cyclic Straining

The constitutive equation of rubber is derived by employing a nonaffine molecular chain network model for an elastic deformation behavior and the reptation theory for a viscoelastic deformation behavior. The results reveal the roles of the individual springs and dashpot, and the strain rate dependence of materials and disentanglement of molecular chains in the monotonic and cyclic deformation behaviors, particularly softening and hysteresis loss, that is, the Mullins effect, occurring in stress-stretch curves under cyclic deformation processes.

Uniaxial Ratchetting of SiCP/6061Al Alloy Composites at Room and High Temperatures

2005 ◽  
Author(s):  
Guozheng Kang
Keyword(s):  
High Temperatures ◽  
Cyclic Deformation ◽  
Volume Fraction ◽  
Stress Amplitude ◽  
Cyclic Softening ◽  
Mean Stress ◽  
Ratcheting Strain ◽  
Macro Scale ◽  
The Matrix ◽  
Sic Particulates

The uniaxial strain cyclic characteristics and ratcheting behaviors of T6-treated SiCP/6061Al alloy composites were studied experimentally at room and high temperatures (573K). The cyclic softening/hardening and ratcheting behaviors of T6-treated composites and un-reinforced matrix were investigated in different loading conditions and with two volume fractions of SiC particulates. It is shown that the cyclic softening/ hardening and ratcheting behaviors of the composites are similar to those of the un-reinforced matrix in macro-scale, i.e., the ratcheting also occurs in the composites during the cyclic stressing with non-zero mean stress, and the ratcheting strain increases with the increasing of stress amplitude and mean stress; however, the addition of SiC particulates into the matrix increases the resistance of the composite to the ratcheting, and the ratcheting strain decreases as the volume fraction of SiC particulates increases. It can be also concluded that the cyclic deformation of the composites has a great temperature-dependence. Some significant conclusions are obtained, which are useful to construct a constitutive model to describe the cyclic deformation of the composites.

Multiaxial Time-Dependent Cyclic Deformation of Stainless Steel at High Temperatures

2006 ◽  
Author(s):  
Qing Gao ◽  
Zhi Shi ◽  
Guozheng Kang ◽  
Yujie Liu
Keyword(s):  
Stainless Steel ◽  
Time Dependence ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Time Dependent ◽  
Nuclear Engineering ◽  
Proportional Loading ◽  
Loading Rates ◽  
Loading Paths ◽  
Cyclic Straining

The multiaxial time-dependent cyclic deformation behavior of stainless steel (i.e., 1Cr18Ni9) was studied experimentally at 250 °C and 700 °C. In the tests, the strain cyclic characteristics and ratcheting behavior of the material were observed under multiaxial cyclic straining/stressing at different loading rates and with various hold-times and non-proportional loading paths. The results show that the cyclic deformation behavior of the material is significantly influenced by the non-proportional loading paths and present apparent time dependence, especially at 700°C. Some significant conclusions useful for the design and assessment of pipe structures in nuclear engineering are obtained.

Strain Rate Dependent Micro- to Macroscopic Deformation Behavior of Carbon-Black Filled Rubber under Monotonic and Cyclic Straining

2007 ◽  
Vol 345-346 ◽  
pp. 53-56
Author(s):  
Yoshihiro Tomita ◽  
K. Azuma ◽  
M. Naito
Keyword(s):  
Carbon Black ◽  
Strain Rate ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Viscoelastic Deformation ◽  
Rate Dependent ◽  
Filled Rubber ◽  
Deformation Behaviors ◽  
The Individual ◽  
Cyclic Straining

A constitutive equation of rubber is derived by employing a nonaffine molecular chain network model for an elastic deformation behavior and the reptation theory for a viscoelastic deformation behavior. The results reveal the roles of the individual springs and dashpot, and the strain rate dependence of materials in the monotonic and cyclic deformation behaviors, particularly softening and hysteresis loss, that is, the Mullins effect, occurring in stress-stretch curves under cyclic deformation processes of carbon black filled rubber..

scholarly journals A Comparison of Amplitude-and Time-Dependent Cyclic Deformation Behavior for Fully-Austenite Stainless Steel 316L and Duplex Stainless Steel 2205

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5594
Author(s):  
Shaohua Li ◽  
Wenchun Jiang ◽  
Xuefang Xie ◽  
Zhilong Dong
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Cyclic Deformation ◽  
Deformation Behavior ◽  
Structural Integrity ◽  
Low Cycle Fatigue ◽  
Cyclic Softening ◽  
Plastic Strain Amplitude ◽  
Cyclic Plasticity ◽  
Stainless Steel 316L

Austenite and duplex stainless steels are widely used in engineering, and the latter exhibits a more excellent combination of mechanical properties and corrosion resistance due to the coexistence of austenite and ferrite and higher nitrogen. However, fatigue failure still threatens their structural integrity. A comprehensive comparison of their cyclic deformation behavior is a major foundation to understand the role of duplex-phase microstructure and nitrogen in the safety assessment of engineering components. Thus, in this paper, the cyclic deformation behavior of fully-austenitic stainless steel 316L and duplex stainless steel 2205 was studied by a series of low cycle fatigue tests with various strain amplitudes, loading rates and tensile holding. A theoretical mechanism diagram of the interaction between nitrogen and dislocation movements during cyclic loads was proposed. Results show that the cyclic stress response of 2205 was the primary cyclic hardening, followed by a long-term cyclic softening regardless of strain amplitudes and rates, while an additional secondary hardening was observed for 316L at greater strain amplitudes. Cyclic softening of 2205 was restrained under slower strain rates or tensile holding due to the interaction between nitrogen and dislocations. The cyclic plasticity of 2205 started within the austenite, and gradually translated into the ferrite with the elevation of the cyclic amplitude, which lead to a decreased hardening ratio with the increase in amplitude and a shorter fatigue life for a given smaller plastic strain amplitude.

Asymmetric Cyclic Deformation Behaviors of Hot-Rolled AZ91 Magnesium Alloy in Rolling Direction

2013 ◽  
Vol 712-715 ◽  
pp. 38-41
Author(s):  
Xiao Min Chen ◽  
Y.C. Lin ◽  
Zheng Hua Liu ◽  
Jian Chen
Keyword(s):  
Magnesium Alloy ◽  
Fatigue Failure ◽  
Cyclic Deformation ◽  
Fatigue Crack Initiation ◽  
Rolling Direction ◽  
Az91 Magnesium Alloy ◽  
Cycle Number ◽  
Ratcheting Strain ◽  
Deformation Behaviors ◽  
Az91 Magnesium

The cyclic deformation behaviors of hotrolled AZ91 magnesium alloy are studied by asymmetrical cyclic stresscontrolled experiments at room temperature. The ratcheting behavior and fatigue failure mechanism are discussed. Results show that: (1) The ratcheting strain increases sharply with the increase of cycle number at the initial stage, and then tends to be a constant after certain cycles. (2) The fatigue crack initiation and stable propagation regions are flat with lamellar structures, while the unstable propagation and rapid fracture regions are coarse with ductile dimples and tearing edges. (3) The residual twins can be seen as potential damage to fatigue failure of the material, due to its irreversibility of cyclic plastic deformation and damage to grain boundaries.

Sign in / Sign up

Export Citation Format

Share Document