scholarly journals Micro-scale and nano-scale strain mapping techniques applied to creep of rocks

2017 ◽  
Author(s):  
Alejandra Quintanilla-Terminel ◽  
Mark Zimmerman ◽  
Brian Evans ◽  
David Kohlstedt
Keyword(s):  
High Temperature ◽  
Laboratory Data ◽  
Confining Pressure ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Computational Techniques ◽  
Strain Partitioning ◽  
Strain Mapping ◽  
Micro Scale

Abstract. Usually, several deformation mechanisms interact to accommodate plastic deformation. Quantifying the contribution of each to the total strain is necessary to bridge from observations of microstructures to geomechanical descriptions and, thus, is a critical component in the extrapolation from laboratory data to field observations. Here, we describe experimental and computational techniques involved in micro-scale strain mapping (MSSM), which allows strain produced during high-pressure, high-temperature deformation experiments to be tracked with high resolution. MSSM relies on the analysis of relative displacement of initially regularly spaced markers after deformation. We present two lithography techniques used to pattern rock substrates at different scales: photolithography and electron-beam lithography. Further, we discuss the challenges of applying the MSSM technique to samples used in high-temperature and pressure experiments. We applied the MSSM technique to a study of strain partitioning during creep of Carrara marble and grain boundary sliding in San Carlos olivine, synthetic forsterite, and Solnhofen limestone at a confining pressure, Pc, of 300 MPa and homologous temperatures, T/Tm, of 0.3 to 0.6. The MSSM technique works very well up to temperatures of 700 ºC. Experimental developments described here show promising results for higher temperature applications.

scholarly journals Microscale and nanoscale strain mapping techniques applied to creep of rocks

Solid Earth ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 751-765 ◽  
Author(s):  
Alejandra Quintanilla-Terminel ◽  
Mark E. Zimmerman ◽  
Brian Evans ◽  
David L. Kohlstedt
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Laboratory Data ◽  
Confining Pressure ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Computational Techniques ◽  
Strain Partitioning ◽  
Strain Mapping

Abstract. Usually several deformation mechanisms interact to accommodate plastic deformation. Quantifying the contribution of each to the total strain is necessary to bridge the gaps from observations of microstructures, to geomechanical descriptions, to extrapolating from laboratory data to field observations. Here, we describe the experimental and computational techniques involved in microscale strain mapping (MSSM), which allows strain produced during high-pressure, high-temperature deformation experiments to be tracked with high resolution. MSSM relies on the analysis of the relative displacement of initially regularly spaced markers after deformation. We present two lithography techniques used to pattern rock substrates at different scales: photolithography and electron-beam lithography. Further, we discuss the challenges of applying the MSSM technique to samples used in high-temperature and high-pressure experiments. We applied the MSSM technique to a study of strain partitioning during creep of Carrara marble and grain boundary sliding in San Carlos olivine, synthetic forsterite, and Solnhofen limestone at a confining pressure, Pc, of 300 MPa and homologous temperatures, T∕Tm, of 0.3 to 0.6. The MSSM technique works very well up to temperatures of 700 °C. The experimental developments described here show promising results for higher-temperature applications.

Grain boundary sliding at high temperature deformation in cold-rolled ODS ferritic steels

2014 ◽  
Vol 452 (1-3) ◽  
pp. 628-632 ◽  
Author(s):  
Yoshito Sugino ◽  
Shigeharu Ukai ◽  
Bin Leng ◽  
Naoko Oono ◽  
Shigenari Hayashi ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Ferritic Steels ◽  
Boundary Sliding ◽  
Cold Rolled

scholarly journals High Temperature Deformation Behavior of 8090 Al-Li Alloy

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Woo Young Jung ◽  
Tae Kwon Ha
Keyword(s):  
High Temperature ◽  
Deformation Behavior ◽  
Internal Variable ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Flow Curves ◽  
Variable Theory ◽  
Self Diffusion ◽  
Internal Variable Theory

High temperature deformation behavior, especially the superplasticity of an 8090 Al-Li alloy, was studied within the recent framework of the internal variable theory of structural superplasticity. In this study, a series of load relaxation tests were conducted at various temperatures ranging from 200°C to 530°C to obtain the flow curves of log ε˙versus log ε. The effect of grain size was also examined by varying the grain sizes through a proper thermomechanical treatment. The flow curves were found to be composite curves consisting of contributions from grain boundary sliding (GBS) and grain matrix deformation (GMD) at superplastic temperatures. The activation energy obtained for GMD was 124.9 kJ/mole in the temperature range from 470°C to 530°C, very similar to that for self-diffusion in pure Al.

Precipitates as Internal Markers for High Temperature Deformation Studies

1974 ◽  
Vol 32 ◽  
pp. 494-495
Author(s):  
K. Nuttall
Keyword(s):  
High Temperature ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Diffusion Creep ◽  
Before And After ◽  
Probable Occurrence ◽  
Boundary Sliding ◽  
And Diffusion

A problem in the study of high temperature deformation mechanisms such as grain boundary sliding or diffusion creep is to obtain good metallographic evidence to demonstrate the probable occurrence of such processes. The difficulty arises because marked changes in microstructure such as those commonly observed after dislocation creep, e.g. grain elongation, sub-grain formation, changes in dislocation distribution, are not usually associated with sliding and diffusion creep so that microstructural comparisons before and after deformation are not too informative. Surface markers are frequently used as an indication of relative grain sliding and rotation, but there are separate difficulties in relating these observations to bulk behaviour.

scholarly journals High Temperature Deformation Behavior of In-Situ Synthesized Titanium-Based Composite Reinforced with Ultra-Fine TiB Whiskers

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1863 ◽  
Author(s):  
Rongjun Xu ◽  
Bin Liu ◽  
Yong Liu ◽  
Yuankui Cao ◽  
Wenmin Guo ◽  
...  
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Failure Modes ◽  
Grain Boundary Sliding ◽  
Coarse Grained ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Powder Metallurgy Method ◽  
Matrix Microstructure

A TiB/Ti-6Al-4V composite reinforced with ultra-fine TiB whiskers (UF-TiB) was prepared by the powder metallurgy method. High temperature compression tests were carried out to study the hot deformation behavior of the UF-TiB/Ti-6Al-4V composite. The compressive deformation was performed in the temperature range of 900–1200 °C and the strain rate range of 0.001–10 s−1. The results showed that stable flow occurred at the condition of 900–1200 °C/0.001–0.01 s−1. The optimum working condition was 900 °C/0.001 s−1, with the deformation mechanism of dynamic recrystallization (DRX). Instable flow occurred when the strain rate was higher than 0.01 s−1, where the failure modes included adiabatic shear deformation, whisker breakage and whisker/matrix debonding. The deformability of the UF-TiB/Ti-6Al-4V composite was much better than the traditional casted and the pressed + sintered TiB/Ti-6Al-4V composites, which are typically reinforced with coarse-grained TiB whiskers. The high deformability was primarily attributed to the ultra-fine reinforcements, which could coordinate the deformation more effectively. In addition, a fine matrix microstructure also had a positive effect on deformability because the fine matrix microstructure could improve the grain boundary sliding.

Investigation on the Microstructure and High Temperature Mechanical Properties of Al3Ti-Mo3Al Two-Phase Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 837-840
Author(s):  
Seiji Miura ◽  
Hiroyuki Shimamura ◽  
Kenji Ohkubo ◽  
Tetsuo Mohri
Keyword(s):  
High Temperature ◽  
Crystallographic Orientation ◽  
Rate Sensitivity ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Orientation Relationships ◽  
Two Phase ◽  
High Temperature Mechanical Properties ◽  
Orientation Distributions

Investigation on the crystallographic orientation relationships among D022-Al3Ti, A15-Mo3Al and high temperature bcc phase consisting of an Al-Mo-Ti ternary alloy with an equi-axed two-phase structure was conducted by FESEM/EBSD analysis. The grains of intermetallic phases have certain crystallographic orientations each other, while the crystallographic orientation distributions become random after a high temperature deformation. This strongly suggests the grain boundary sliding and grain rotating govern the high temperature deformation, which is consistent with the fact that the strain-rate sensitivity m is 0.3 or higher during a steady-state compressive deformation.

High temperature deformation behavior of titanium samples with superplastic layer

1995 ◽  
Vol 10 (4) ◽  
pp. 864-869 ◽  
Author(s):  
M.G. Zelin ◽  
Q. Li ◽  
R.Z. Valiev ◽  
P. Lukač ◽  
A.K. Mukherjee
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Grain Boundary Sliding ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Layer By Layer ◽  
Boundary Sliding

The progress of high temperature deformation in samples of two commercial titanium alloys with superplastic (SP) structure, non-SP structure, and with an SP layer sandwiched between the non-SP regions has been studied on the scale of the entire deformed volume and on the scale of grain groups. The results of mechanical behavior showed that samples with SP layer exhibit higher stress level than those with completely SP structure and higher strain rate sensitivity than those with completely non-SP structure. Samples with SP layer demonstrate a more pronounced deccrease in strain rate sensitivity with the increase of strain than samples with completely SP structure. Deformation in the SP layer proceeds as grain shear in a layer-by-layer manner. The deformation of SP layer through the operation of cooperative grain boundary sliding, i.e., sliding of grain groups as an entity along certain grain boundary surfaces, provides the main contribution to the total strain.

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