Understanding Creep Behavior of Semicrystalline Polymer via Coarse‐Grained Modeling

2019 ◽  
Vol 57 (24) ◽  
pp. 1779-1791 ◽  
Author(s):  
Chao Wu ◽  
Ruidong Wu ◽  
Wenjie Xia ◽  
Lik‐ho Tam
Keyword(s):  
Creep Behavior ◽  
Semicrystalline Polymer ◽  
Coarse Grained

scholarly journals Spherical nanoindentation creep behavior of nanocrystalline and coarse-grained CoCrFeMnNi high-entropy alloys

2016 ◽  
Vol 109 ◽  
pp. 314-322 ◽  
Author(s):  
Dong-Hyun Lee ◽  
Moo-Young Seok ◽  
Yakai Zhao ◽  
In-Chul Choi ◽  
Junyang He ◽  
...  
Keyword(s):  
Creep Behavior ◽  
Coarse Grained ◽  
High Entropy Alloys ◽  
High Entropy

Nanoindentation creep behavior of coarse-grained and ultrafine-grained pure magnesium and AZ31 alloy

2017 ◽  
Vol 698 ◽  
pp. 348-355 ◽  
Author(s):  
Jiangjiang Hu ◽  
Wei Zhang ◽  
Guangli Bi ◽  
Jinwen Lu ◽  
Wangtu Huo ◽  
...  
Keyword(s):  
Creep Behavior ◽  
Az31 Alloy ◽  
Pure Magnesium ◽  
Coarse Grained ◽  
Ultrafine Grained

Superplasticity-like creep behavior of coarse grained ternary Al alloys

2010 ◽  
Vol 20 (4) ◽  
pp. 564-571 ◽  
Author(s):  
Jun QIAO ◽  
E.M. TALEFF
Keyword(s):  
Creep Behavior ◽  
Al Alloys ◽  
Coarse Grained

scholarly journals Creep Resistance of S304H Austenitic Steel Processed by High-Pressure Sliding

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 331
Author(s):  
Petr Kral ◽  
Jiri Dvorak ◽  
Vaclav Sklenicka ◽  
Zenji Horita ◽  
Yoichi Takizawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Austenitic Steel ◽  
Creep Behavior ◽  
Creep Strength ◽  
Coarse Grained ◽  
Σ Phase ◽  
Ultrafine Grained ◽  
Mean Grain Size ◽  
Ultrafine Grained Microstructure ◽  
Thermal Stability Of

Sheets of coarse-grained S304H austenitic steel were processed by high-pressure sliding (HPS) at room temperature and a ultrafine-grained microstructure with a mean grain size of about 0.14 µm was prepared. The microstructure changes and creep behavior of coarse-grained and HPS-processed steel were investigated at 500–700 °C under the application of different loads. It was found that the processing of S304H steel led to a significant improvement in creep strength at 500 °C. However, a further increase in creep temperature to 600 °C and 700 °C led to the deterioration of creep behavior of HPS-processed steel. The microstructure results suggest that the creep behavior of HPS-processed steel is associated with the thermal stability of the SPD-processed microstructure. The recrystallization, grain growth, the coarsening of precipitates led to a reduction in creep strength of the HPS-processed state. It was also observed that in the HPS-processed microstructure the fast formation of σ-phase occurs. The σ-phase was already formed during slight grain coarsening at 600 °C and its formation was enhanced after recrystallization at 700 °C.

scholarly journals Twinning-Induced Abnormal Strain Rate Sensitivity and Indentation Creep Behavior in Nanocrystalline Mg Alloy

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7104
Author(s):  
Shilun Yu ◽  
Yingchun Wan ◽  
Chuming Liu ◽  
Zhiyong Chen ◽  
Xiangyang Zhou
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Creep Behavior ◽  
Nanocrystalline Materials ◽  
Volume Fraction ◽  
Chemical Properties ◽  
Rate Sensitivity ◽  
Coarse Grained ◽  
Indentation Creep ◽  
Zr Alloy

Nanocrystalline materials exhibit many unique physical and chemical properties with respect to their coarse-grained counterparts due to the high volume fraction of grain boundaries. Research interests on nanocrystalline materials around the world have been lasting over the past decades. In this study, we explored the room temperature strain rate sensitivity and creep behavior of the nanocrystalline Mg–Gd–Y–Zr alloy by using a nanoindentation technique. Results showed that the hardness and creep displacements of the nanocrystalline Mg–Gd–Y–Zr alloy decreased with increasing loading strain rate. That is, the nanocrystalline Mg–Gd–Y–Zr alloy showed negative strain rate sensitivity and its creep behavior also exhibited negative rate dependence. It was revealed that the enhanced twinning activities at higher loading strain rates resulted in reduced hardness and creep displacements. The dominant creep mechanism of the nanocrystalline Mg–Gd–Y–Zr alloy is discussed based on a work-of-indentation theory in this paper.

Compressive Creep Behavior in Coarse Grained Polycrystals of Ti3Al and its Dependence on Binary Alloy Compositions

2004 ◽  
Vol 842 ◽  
Author(s):  
Tohru Takahashi ◽  
Yuki Sakaino ◽  
Shunzi Song
Keyword(s):  
Creep Behavior ◽  
True Strain ◽  
Pure Aluminum ◽  
Average Diameter ◽  
Coarse Grained ◽  
Creep Tests ◽  
Compressive Creep ◽  
Rate Region ◽  
Small Primary ◽  
Equiaxed Grains

ABSTRACTCompressive creep behavior has been investigated on coarse grained Ti3Al alloys with aluminum contents ranging from 15mol%Al to 42mol%Al, in order to obtain basic information concerning the chemical composition effect on creep of Ti3Al. Pure aluminum and titanium of 99.99% purity were arc-melted into small ingots weighing about 10grams under an argon atmosphere. The resulting microstructures after the hot deformation and vacuum annealing contained equiaxed grains whose average diameter ranged from 125 to 192 micrometers except alloys containing 40 and 42 mol% aluminum.Compressive creep tests were performed in vacuum on parallelepiped specimens with dimensions of 2mm×2mm×3mm. The applied compressive stress was 159MPa, and the test temperature was around 1200K.A very small primary transient and the minimum creep rate region followed by a gradual creep acceleration were observed in the materials containing aluminum up to 25mol%. In contrast to this, the materials containing more aluminum than 25mol% showed greater primary transient where creep deceleration continued up to about 0.1 true strain. Dual phase materials containing the γ phase showed small primary transient probably due to the constraint from the γ phase.

Tensile and Compressive Creep Behavior of Coarse-Grained Mg-Al-Sr Castings

2007 ◽  
pp. 171-174
Author(s):  
Peng Zhao ◽  
Qu Dong Wang ◽  
Chun Quan Zhai ◽  
Wen Jiang Ding
Keyword(s):  
Creep Behavior ◽  
Coarse Grained ◽  
Compressive Creep

The Alteration of the Pore Spaces in Sandstones

1973 ◽  
Vol 31 ◽  
pp. 210-211
Author(s):  
R. E. Ferrell ◽  
G. G. Paulson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
The Other ◽  
Coarse Grained ◽  
Depositional Fabric ◽  
Soluble Components ◽  
Scanning Electron ◽  
Shape And Size

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.

On the Origin of the Microscystalline Structure in Rapidly Solidified IN-100 Powder

1977 ◽  
Vol 35 ◽  
pp. 260-261
Author(s):  
J. M. Walsh ◽  
K. P. Gumz ◽  
J. C. Whittles ◽  
B. H. Kear
Keyword(s):  
The Other ◽  
Coarse Grained ◽  
Microcrystalline Structure ◽  
Routine Examination ◽  
Atomization Process ◽  
Centrifugal Atomization ◽  
Splat Quenching ◽  
Powder Particles ◽  
Dendritic Microstructures ◽  
Rapidly Solidified

During a routine examination of the microstructure of rapidly solidified IN-100 powder, produced by a newly-developed centrifugal atomization process1, essentially two distinct types of microstructure were identified. When a high melt superheat is maintained during atomization, the powder particles are predominantly coarse-grained, equiaxed or columnar, with distinctly dendritic microstructures, Figs, la and 4a. On the other hand, when the melt superheat is reduced by increasing the heat flow to the disc of the rotary atomizer, the powder particles are predominantly microcrystalline in character, with typically one dendrite per grain, Figs, lb and 4b. In what follows, evidence is presented that strongly supports the view that the unusual microcrystalline structure has its origin in dendrite erosion occurring in a 'mushy zone' of dynamic solidification on the disc of the rotary atomizer.The critical observations were made on atomized material that had undergone 'splat-quenching' on previously solidified, chilled substrate particles.

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