Influence of Heat Treatment on Low-Cycle Fatigue Behavior of AZ61 Magnesium Alloy

In order to identify the influence of solid solution, aging and solid solution plus aging treatments on the low-cycle fatigue behavior of the extruded AZ61 magnesium alloy, the low-cycle fatigue tests were performed at room temperature for the extruded AZ61 magnesium alloy with different treating states. The results indicate that the cyclic stress response behavior of the extruded AZ61 magnesium alloy exhibits both cyclic strain hardening and stability. The solid solution, aging and solid solution plus aging treatments tend to decrease the cyclic deformation resistance of the extruded AZ61 alloy in most conditions. The solid solution treatment can enhance the fatigue lives of the extruded AZ61 alloy at medium total strain amplitudes. In addition, the aging treatment can prolong the low-cycle fatigue lives of the AZ61 alloy at most total strain amplitudes, while the case for the solid solution plus aging treatment is just contrary. For the extruded AZ61 alloy with different treating states, a linear relationship between cyclic stress amplitude and plastic strain amplitude is noted.

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

MATEC Web of Conferences ◽

10.1051/matecconf/201816522001 ◽

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.

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Low Cycle Fatigue Behavior of Spray Formed Superalloy Rings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.399-401.1937 ◽

2011 ◽

Vol 399-401 ◽

pp. 1937-1941 ◽

Cited By ~ 1

Author(s):

Wen Yong Xu ◽

Guo Qing Zhang ◽

Zhou Li

Keyword(s):

Strain Amplitude ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Hysteresis Loops ◽

Cyclic Strain ◽

Cyclic Hardening ◽

Cyclic Stress ◽

Total Strain ◽

Total Strain Amplitude ◽

Cycle Fatigue

Low cycle fatigue behavior of spray formed superalloy GH738 at 650°C has been investigated under fully reversed total strain-controlled mode. When strain amplitude (Δεt/2) is between 0.32% and 0.4%, cyclic stress response is stable under fully reversed constant total strain amplitude. The stabilized hysteresis loops narrowing sharply to a straight line indicates that the alloy exhibits typical elastic strain. The crack initiates single site from the surface. When strain amplitude is between 0.6% and 1.0%, cyclic hardening is observed until fracture. The tendency for hardening is found to increase with strain amplitude. The hyperesis loops expand gradually, which indicates that plastic deformation happens during cyclic deformation process. The crack initiates multi-sites from the surface. The cyclic strain-stress relationship of spray formed GH738 at 650°C can be illustrated by Δσ/2 =2017(Δεp/2)0.1489.The total strain-life function can expressed by Δεt/2=0.0071(2Nf)-0.0781+0.0647(2Nf) )-0.4914.

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Microstructure and Low-Cycle Fatigue Behavior of Al-9Si-4Cu-0.4Mg-0.3Sc Alloy with Different Casting States

Materials ◽

10.3390/ma13030638 ◽

2020 ◽

Vol 13 (3) ◽

pp. 638 ◽

Cited By ~ 1

Author(s):

Guanyi Wang ◽

Xin Che ◽

Zhipeng Zhang ◽

Haoyu Zhang ◽

Siqian Zhang ◽

...

Keyword(s):

Electron Microscope ◽

Cyclic Deformation ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Cyclic Stress ◽

Fatigue Tests ◽

Total Strain ◽

Cycle Fatigue ◽

Metal Mold ◽

Die Cast

The low-cycle fatigue behavior of Al-9Si-4Cu-0.4Mg-0.3Sc alloy with different casting states was investigated by performing low-cycle fatigue tests and by means of observations and analysis with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). It was found that the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys exhibited the cyclic stress response of strain hardening under all imposed total strain amplitudes. The cyclic deformation resistance and fatigue life of the metal-mold cast Al-9Si-4Cu-0.4Mg-0.3Sc alloy were lower than those of the die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloy. The plastic strain and elastic strain amplitudes of the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys were linearly related to the number of reversals to failure, which obeyed the Coffin-Manson and Basquin formulas, respectively. The results of TEM observation revealed that at all imposed total strain amplitudes, the cyclic deformation mechanisms of the metal-mold cast and die-cast Al-9Si-4Cu-0.4Mg-0.3Sc alloys were planar slip and wavy slip at the lower and higher strain amplitudes, respectively.

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103 Total Strain Controlled Low Cycle Fatigue Behavior of Extruded AZ31 Magnesium Alloy

The Proceedings of Conference of Hokuriku-Shinetsu Branch ◽

10.1299/jsmehs.2009.46.5 ◽

2009 ◽

Vol 2009.46 (0) ◽

pp. 5-6

Author(s):

Tomohiro KAMINASHI ◽

Kazuaki SHIOZAWA ◽

Tutomu MURAI ◽

Toru TAKAHASHI

Keyword(s):

Magnesium Alloy ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Az31 Magnesium Alloy ◽

Total Strain ◽

Cycle Fatigue

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LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512003261 ◽

2012 ◽

Vol 06 ◽

pp. 251-256

Author(s):

HO-YOUNG YANG ◽

JAE-HOON KIM ◽

KEUN-BONG YOO

Keyword(s):

Fatigue Life ◽

Strain Energy ◽

Life Prediction ◽

Prediction Models ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Total Strain ◽

Cycle Fatigue ◽

Total Strain Range ◽

Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

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