Cyclic Hardening Behavior of Extruded AZ31B Magnesium Alloy during Low Cycle Fatigue Process

2013 ◽  
Vol 395-396 ◽  
pp. 234-237
Author(s):  
Guo Sheng Duan ◽  
Bao Lin Wu ◽  
Xiang Zhao ◽  
Gang Zhao
Keyword(s):  
Magnesium Alloy ◽  
Dislocation Density ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Strain Ratio ◽  
Plastic Strain Amplitude ◽  
Cycle Fatigue ◽  
Az31b Magnesium Alloy ◽  
Hardening Behavior

The strain-controlled fatigue tests on extruded AZ31B magnesium alloy were conducted under the uniaxial loading with strain ratio Rε=-∞, frequency of 0.1 Hz and strain amplitude of 2% at room temperature. The cyclic hardening behavior was investigated. It was found that, during the low cycle fatigue (LCF) process, as the number of cycles increases, the stress amplitude increases corresponding to the decrease of the plastic strain amplitude. The development of dislocation density can be described as the function of the number of fatigue cycles, and the behavior can be explained well based on the dislocation density development model.

scholarly journals Low-cycle fatigue behavior of extruded Al-7Zn-2Mg-1.5Cu-0.2Sc-0.1Zr alloy at room and low temperatures

2018 ◽  
Vol 165 ◽  
pp. 22001
Author(s):  
Zhu Qingyan ◽  
Chen Lijia ◽  
Xu Chengji ◽  
Che Xin ◽  
Li Feng
Keyword(s):  
Low Temperature ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Aging Treatment ◽  
Cyclic Hardening ◽  
Strain Ratio ◽  
Plastic Strain Amplitude ◽  
Total Strain ◽  
Cycle Fatigue

Due to the low density and high specific strength, aluminum alloys have been considered for automotive and aerospace applications. The aluminum components usually service in the conditions of low temperature and dynamic loading. Therefore, the research on the low temperature fatigue performances of Al alloys has great significance. The lowcycle fatigue tests for the extruded Al-7Zn-2Mg-1.5Cu-0.2Sc-0.1Zr alloy subjected to solution plus aging treatment have been conducted at 25°C and -40°C, respectively. The strain ratio and cyclic frequency applied in the low-cycle fatigue test were -1 and 0.5Hz, respectively. The experimental results show that at 25°C, the alloy exhibits the cyclic hardening at the total strain amplitudes of 1.0% and 1.2%, and the cyclic stabilization at the total strain amplitudes of 0.4%, 0.6% and 0.8%. At -40°C, however, the cyclic stability is observed during whole fatigue deformation at the total strain amplitudes of 0.4%, 0.5%, 0.6%, 0.7% and 0.8%. The relationship between the elastic strain amplitude, plastic strain amplitude and reversals to failure can be described by Basquin and Coffin-Manson equations, respectively. In addition, the observation results of fatigue fracture surfaces reveal that the cracks initiate at the free surface of fatigue specimen and propagate in a transgranular mode.

Low Cycle Fatigue Behavior of As-Extruded AZ31 Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 202-207
Author(s):  
Ping Li Mao ◽  
Zheng Liu ◽  
Yang Li ◽  
Li Jia Chen
Keyword(s):  
Magnesium Alloy ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Fatigue Cracks ◽  
Az31 Alloy ◽  
Plastic Strain Amplitude ◽  
Az31 Magnesium Alloy ◽  
Total Strain Amplitude ◽  
Fracture Surfaces

The investigation on fatigue behavior and fracture surfaces of fatigued specimens of as-extruded AZ31 magnesium alloy can provide a reliable theoretical foundation for both fatigue resistant design and reasonable application of magnesium alloys. Through total-strain-amplitude controlled fatigue tests and analysis on fracture surfaces of fatigued specimens, the behavior of cyclic stress response and fatigue life as well as fracture mechanism were identified for as-extruded AZ31 magnesium alloy. The experimental results show that the extruded AZ31 alloy exhibits significant cyclic strain hardening, the relation between elastic strain amplitude, plastic strain amplitude and reversals to failure can be described by Basquin and Coffin-Manson equations respectively. In addition, it has been found that fatigue cracks initiate and propagate in a transgranular mode.

Influence of Heat Treatment Condition on Low Cycle Fatigue Life of a Rolled AZ80 Magnesium Alloy Sheet

2011 ◽  
Vol 239-242 ◽  
pp. 1309-1312
Author(s):  
Zhong Jun Wang
Keyword(s):  
Fatigue Life ◽  
Magnesium Alloy ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Solution Treatment ◽  
Alloy Sheet ◽  
Total Strain ◽  
Total Strain Amplitude ◽  
Cycle Fatigue ◽  
Az80 Magnesium Alloy

In this paper, the influence of ageing and solution treatment on the low cycle fatigue behavior of a rolled AZ80 magnesium alloy sheet was investigated at constant total strain amplitudes between 0.003 and 0.01. It was observed that fatigue life of the alloy sheet at as-rolled, ageing and solution treatment conditions can be described well by Coffin-Manson and Basquin’s equations. The fatigue parameters follow the two equations were evaluated. With increasing total strain amplitude, the fatigue life of the three conditions decreased. At the lowest total strain amplitude of 0.003, the fatigue life of the as-rolled alloy sheet was the biggest. However, at the highest total strain amplitude of 0.01, the fatigue life of solution treated alloy sheet was the biggest, and that of the ageing treated alloy sheet was the shortest.

Low cycle fatigue behavior of extruded AZ31B magnesium alloy

2013 ◽  
Vol 23 (6) ◽  
pp. 1589-1594 ◽  
Author(s):  
Chang-jian GENG ◽  
Bao-lin WU ◽  
Xing-hao DU ◽  
Yan-dong WANG ◽  
Yu-dong ZHANG ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Az31b Magnesium Alloy

scholarly journals Microstructural Evolution along the NiCrMoV Steel Welded Joints Induced by Low-Cycle Fatigue Damage

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 811
Author(s):  
Shuo Weng ◽  
Yuhui Huang ◽  
Mingliang Zhu ◽  
Fuzhen Xuan
Keyword(s):  
Dislocation Density ◽  
Grain Boundaries ◽  
Strain Amplitude ◽  
Microstructural Evolution ◽  
Welded Joints ◽  
Low Cycle Fatigue ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Nicrmov Steel

The degradation of mechanical properties of materials is essentially related to microstructural changes under service loadings, while the inhomogeneous degradation behaviors along welded joints are not well understood. In the present work, microstructural evolution under low-cycle fatigue in base metal (BM) and weld metal (WM) of NiCrMoV steel welded joints were investigated by miniature tensile tests and microstructural observations. Results showed that both the yield strength and ultimate tensile strength of the BM and WM decreased after low-cycle fatigue tests, which were attributed to the reduction of dislocation density and formation of low-energy structures. However, the microstructural evolution mechanisms in BM and WM under the same cyclic loadings were different, i.e., the decrease of dislocation density in BM was attributed to the dislocation pile-ups along the grain boundaries, dislocation tangles around the carbides at the lower strain amplitudes (±0.3% or ±0.5%). Additionally, when the strain amplitude was ±8%, the dislocation density was further decreased by the formation of subgrains in BM. For WM, the dislocation density decreased with the increase of strain amplitude, which was mainly caused by the dislocation pile-ups along the grain boundaries and the formation of subgrains.

Low-Cycle Fatigue Fracture Behavior of Superalloy GH4586 at Elevated Temperature

2004 ◽  
Vol 449-452 ◽  
pp. 337-340 ◽  
Author(s):  
Lei Wang ◽  
Tong Cui ◽  
Jun Ying Lü ◽  
Hong Cai Yang ◽  
Guang Pu Zhao
Keyword(s):  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Fatigue Property ◽  
Plastic Strain Amplitude ◽  
Cycle Fatigue ◽  
Cyclic Life ◽  
Creep Fatigue ◽  
Fatigue Fracture Behavior ◽  
Higher Sensitivity

Low-cycle fatigue property of superalloy GH4586 was investigated using a stress amplitude-controlled mode at 1023K. Fracture surface was examined with a scanning electronic microscopy. It was found that the cyclic life can be illustrated by Manson-Coffin at all strain levels. The fatigue cracks initiate primarily on the surface of the specimen. The plastic strain amplitude responded to the cyclic loading shows higher sensitivity than that of the elastic strain amplitude. It was demonstrated that the failure of the present alloy is in a manner of creep-fatigue feature.

Low cycle fatigue behavior of the textured AZ31B magnesium alloy under the asymmetrical loading

2013 ◽  
Vol 560 ◽  
pp. 618-626 ◽  
Author(s):  
C.J. Geng ◽  
B.L. Wu ◽  
X.H. Du ◽  
Y.D. Wang ◽  
Y.D. Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Az31b Magnesium Alloy

Influence of Temperature on Low Cycle Fatigue and Ratcheting Behavior of SA333 Gr-6 C-Mn Steel

2020 ◽  
Vol 978 ◽  
pp. 152-160
Author(s):  
Girendra Kumar ◽  
H.N Bar ◽  
S. Sivaprasad ◽  
Ashok Kumar
Keyword(s):  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Cyclic Hardening ◽  
Plastic Strain Amplitude ◽  
Total Strain Amplitude ◽  
Loading Conditions ◽  
Influence Of Temperature ◽  
Plastic Deformation Behavior ◽  
Influence Of Temperature On ◽  
Cyclic Plastic Deformation

The aim of this investigation is to study the influence of temperature on the cyclic plastic deformation behavior of SA333 Gr-6 steel at two loading conditions. Strain-controlled cyclic loading experiments were carried out at ± 0.5% total strain amplitude, 1×10-3 s-1 strain rate, and temperature varied from RT to 400°C, whereas stress controlled ratcheting experiments were conducted at fixed mean stress (σm) of 50 MPa and stress amplitude (σa) of 400 MPa, 115 MPa s-1 stress rate, and in the temperature range of RT to 350°C. The investigated steel shows cyclic hardening characteristic at DSA temperature regime in both the loading condition. The steel shows lower fatigue lives at 250°C and 300°C temperatures even though plastic strain amplitude is smaller. The ratcheting life of the steel increases and strain accumulation decreases with the increase in temperature up to 300°C and on further increment in temperature ratcheting life get decreased. The steel shows greater cyclic hardening at both the loading conditions at 300°C.

Low-Cycle Fatigue Behavior of Magnesium Alloy AZ91

2005 ◽  
Vol 488-489 ◽  
pp. 725-728 ◽  
Author(s):  
Li Jia Chen ◽  
Jian Shen ◽  
Wei Wu ◽  
Feng Li ◽  
Yue Wang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Strain ◽  
Plastic Strain Amplitude ◽  
Az91 Alloy ◽  
Total Strain Amplitude ◽  
Alloy Az91 ◽  
Magnesium Alloy Az91

Fully-reversed total-strain-amplitude-controlled fatigue tests were performed in laboratory air at room temperature for the magnesium alloy AZ91. Experimental results showed that during the experiment significant cyclic strain hardening occurred throughout the imposed strain amplitudes. It was found that the relationship between plastic strain amplitude, elastic strain amplitude and reversals to failure can be well described by Basquin and Coffin-Manson equations. In addition, the strain fatigue parameters of the AZ91 alloy were determined through analyzing the corresponding strain fatigue life data.

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