Study on Brittle-Ductile Transition of Monocrystal Silicon at High Temperature and its Application to Ductile Mode Cutting.

Experiments on granite under uniaxial compression at high temperature of 25~850°C and after high temperature of 25~1300°C were conducted to study the effect of temperature on rock strength and deformation quality. The results show that: (1) Fitting curves between temperature strain and thermal expansion coefficient with temperature are closely first order growth exponential function relation at high temperature. Temperature strain has mutagenicity after high temperature, which can not reflect rock deformation law at high temperature exactly. (2)Mechanical properties of granite weak continuously at high temperature. Compressive strength and elastic modulus show second order attenuation trend of exponential law. But mechanical properties show mutation state after high temperature, which is closely related to the alteration of rock crystal form and brittle-ductile transition. Regression curves between compressive strength and elastic modulus with temperature are closely polynomial curve. The results reflect the fundamental regulation of granite’s interior structure changing under the action of different temperature, which will provide some reference value to rock engineering involved in high temperature.

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Ductile Mode Cutting of Brittle Materials

10.1007/978-981-32-9836-1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Kui Liu ◽

Hao Wang ◽

Xinquan Zhang

Keyword(s):

Brittle Materials ◽

Ductile Mode ◽

Ductile Mode Cutting

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The kinematic vorticity analysis of ductile shear zones of Ambaji Granulite, NW India and its tectonic implications

10.5194/egusphere-egu2020-7397 ◽

2020 ◽

Author(s):

Sudheer Kumar Tiwari ◽

Anouk Beniest ◽

Tapas Kumar Biswal

Keyword(s):

High Temperature ◽

Low Temperature ◽

Lateral Displacement ◽

Pure Shear ◽

Tectonic Setting ◽

Shear Zones ◽

Normal Faults ◽

Temperature Phase ◽

Brittle Ductile Transition ◽

Deformation Phase

The Neoproterozoic (834 &#8211; 778 Ma) Ambaji granulite witnessed four deformation phases (D1- D4), of which the D2 deformation phase was most significant for the exhumation of granulites in the ductile regime. We performed a field study to investigate the tectonic evolution of the D2 deformation phase and investigated the deformation evolution of the ductile extrusion of the Ambaji granulite by estimating the vorticity of flow (Wm) with the Rigid Grain Net and strain ratio/orientation techniques.During the D2 deformation phase, the S1 fabric was folded by F2 folds that are coaxial with the F1 folds. The F2 folds were produced in response to NW-SE compression. Because the large shear zones are oriented parallel to the axial plane of the F2 folds, they likely formed simultaneously during the D2 deformation phase. Compression during the D2 deformation phase accommodated most of the exhumation of the granulite along the shear zones. D2 shearing was constrained between 834&#8239;&#177;&#8239;7 to 778&#8239;&#177;&#8239;8&#8239;Ma (Monazite ages).The shear zones evolved from a high temperature (>700&#8239;&#176;C) thrust-slip shearing event in the lower-middle crust to a low temperature (450&#8239;&#176;C) retrograde sinistral shearing event at the brittle-ductile-transition (BDT). The&#160;Wm&#160;estimates of 0.32&#8211;0.40 and 0.60 coincide with the high temperature event and suggests pure shear dominated deformation. The low temperature phase coincides with&#160;Wm&#160;estimates of 0.64&#8211;0.87 and ~1.0, implying two flow regimes. The shear zone was first affected by general non-coaxial deformation and gradually became dominated by simple shearing.We interpreted that the high temperature event happened in a compressive tectonic regime, which led to horizontal shortening and vertical displacement of the granulite to the BDT. The low temperature event occurred in a transpressive tectonic setting that caused the lateral displacement of the granulite body at BDT depth. The Wm values indicate a non-steady strain during the exhumation of granulite. From the BDT to surface, the Ambaji granulite exhumed through the NW-SE directed extension for normal faults via brittle exhumation through crustal extension and thinning.

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