A thermally activated model for room temperature creep in nanocrystalline Au films at intermediate stresses

2013 ◽  
Vol 68 (8) ◽  
pp. 551-554 ◽  
Author(s):  
Nikhil Karanjgaokar ◽  
Fernando Stump ◽  
Philippe Geubelle ◽  
Ioannis Chasiotis
Keyword(s):  
Room Temperature ◽  
Thermally Activated ◽  
Temperature Creep ◽  
Room Temperature Creep

scholarly journals Room-Temperature Creep Behavior and Activation Volume of Dislocation Nucleation in a LiTaO3 Single Crystal by Nanoindentation

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1683 ◽  
Author(s):  
Yi Ma ◽  
Xianwei Huang ◽  
Yuxuan Song ◽  
Wei Hang ◽  
Taihua Zhang
Keyword(s):  
Creep Deformation ◽  
Room Temperature ◽  
Activation Volume ◽  
Rate Sensitivity ◽  
Dislocation Nucleation ◽  
Orientation Effect ◽  
Plastic Behavior ◽  
Mechanical Heterogeneity ◽  
Temperature Creep ◽  
Room Temperature Creep

The crystal orientation effect on mechanical heterogeneity of LiTaO3 single crystals is well known, whilst the time-dependent plastic behavior, i.e., creep is still short of understanding. Relying on nanoindentation technology, we systematically studied room-temperature creep flows at various holding depths (100 nm to 1100 nm) in three typical orientations namely the X-112°, Y-36° and Y-42° planes. Creep resistance was much stronger in the X-112° plane than the others. In the meanwhile, creep features were similar in the Y-36° and Y-42° planes. The orientation effect on creep deformation was consistent with that on hardness. The nanoindentation length scale played an important role in creep deformation that creep strains were gradually decreased with the holding depth in all the planes. Based on strain rate sensitivity and yield stress, the activation volumes of dislocation nucleation were computed at various nanoindentation depths. The activation volumes ranged from 5 Å3 to 23 Å3 for the Y-36° and Y-42° planes, indicating that a point-like defect could be the source of plastic initiation. In the X-112° plane, the activation volume was between 6 Å3 and 83 Å3. Cooperative migration of several atoms could also be the mechanism of dislocation activation at deep nanoindentation.

Room Temperature Creep Behaviour of Ramming Paste Baked at Different Temperatures

2014 ◽  
pp. 1221-1226 ◽  
Author(s):  
Pierre-Olivier St-Arnaud ◽  
Donald Picard ◽  
Houshang Alamdari ◽  
Donald Ziegler ◽  
Mario Fafard
Keyword(s):  
Room Temperature ◽  
Creep Behaviour ◽  
Temperature Creep ◽  
Different Temperatures ◽  
Room Temperature Creep

Room Temperature Creep and its Effect on Fatigue Crack Growth in a X70 Steel with Various Microstructures

2007 ◽  
Vol 353-358 ◽  
pp. 138-141 ◽  
Author(s):  
De Fu Nie ◽  
Jie Zhao
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Room Temperature ◽  
Pipeline Steel ◽  
Threshold Region ◽  
Single Wave ◽  
Temperature Creep ◽  
Crack Tips ◽  
Room Temperature Creep

Fatigue crack growth (FCG) tests have been performed in an X70 steel with various microstructures (respectively in the as-received and the normalized condition). The effect of room temperature creep (RTC) on FCG behavior has been investigated by comparing with single wave overloads (SWOL). The as-received X70 pipeline steel has high FCG rate at the near-threshold region. While at the Paris region, FCG rate seems insensitive to the microstructure. In both conditions, time-dependent deformation is observed at crack tips (i.e., RTC), which increases with increasing stress-intensity-factor. And this deformation has a high value in the normalized state, under identical testing conditions. Both RTC and SWOL can bring subsequent fatigue crack growth a very short initial acceleration before deceleration, whereas the former induces more serious deceleration and retardation, which attributes to more significant crack closures.

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