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Showing papers on "Slip (materials science) published in 1972"


Journal ArticleDOI
TL;DR: In this paper, a model for oblique convergence between plates of lithosphere is proposed in which at least a fraction of slip parallel to the plate margin results in transcurrent movements on a nearly vertical fault which is located on the continental side of a zone of plate consumption.
Abstract: A model for oblique convergence between plates of lithosphere is proposed in which at least a fraction of slip parallel to the plate margin results in transcurrent movements on a nearly vertical fault which is located on the continental side of a zone of plate consumption. In an extreme case of complete decoupling only the component of slip normal to the plate margin can be inferred from underthrusting. Recent movements in the western Sunda region provide the most convincing evidence for decoupling of slip, which in this region is thought to be oblique to the plate margin. A speculative model for convergence along the margins of the Philippine Sea is constructed from an inferred direction of oblique slip in the Philippine region. This model requires that the triple point formed by the junction of the Japanese and Izu-Bonin trenches and the Nankai trough migrate along the Sagami trough.

1,365 citations


Journal ArticleDOI
TL;DR: In this paper, a general time-independent constitutive framework for crystals capable of crystallographic shearing is presented, where no restrictions are placed on their elasticity or on the amounts of slip.
Abstract: A general time-independent constitutive framework is constructed for crystals capable of crystallographic shearing. No restrictions are placed on their elasticity or on the amounts of slip. In deriving properly-objective relations due account is taken of the separate motions of the material and lattice. A precise specification of the structure of the flow rule leads to conditions for the existence of plastic potentials, as well as to an exact statement of the slip criterion required for normality of the plastic strain-increment in conjugate variables. Objective hardening laws are also examined and sufficiency conditions obtained for uniqueness of the slip magnitudes.

935 citations


Journal ArticleDOI
TL;DR: Friction experiments have been conducted on porous sandstone, quartzite, graywacke, and granite in the 20-to 850-bar normal stress range as mentioned in this paper, and the coefficient of static friction of surfaces with gouge exhibits a highly time-dependent behavior.
Abstract: Friction experiments have been conducted on porous sandstone, quartzite, graywacke, and granite in the 20- to 850-bar normal stress range. Sliding on clean rough-ground surfaces is initially stable for this range. However, as powered rock debris accumulates on the slip surface, stick slip becomes the dominant mode of sliding. The coefficient of static friction of surfaces with gouge exhibits a highly time-dependent behavior. Static friction increases with the logarithm of the time that adjacent blocks remain in stationary contact. Over the entire range of normal stresses the static friction for 105-sec intervals between stick-slip events is greater than the static friction for 15-sec intervals by 6 to 10%. This behavior may be significant in understanding the mechanisms of earthquake foreshocks, aftershocks, and fault creep.

693 citations


Journal ArticleDOI
F. Secco d' Aragona1
TL;DR: In this paper, a dilute aqueous solution of an alkali dichromate and hydrofluoric acid is used to reveal dislocations and other lattice defects in (100) planes of silicon.
Abstract: A new etch composed of a dilute aqueous solution of an alkali dichromate and hydrofluoric acid, for suitably revealing dislocations and other lattice defects in (100) planes of silicon, is reported. The etch is fast (typically 5 min), brings out both lineage (low angle grain boundaries) and slip lines, and works over a wide range of resistivities for n‐ and p‐type material. The application of the etch is not restricted to (100) planes; dislocation etch pits are formed on all crystallographic orientations. The same etching characteristics were found with dilute aqueous solutions prepared from various chromium compounds and hydrofluoric acid.

634 citations


Journal ArticleDOI
TL;DR: In this article, a model for the interaction between a matrix slip dislocation and a second phase particle of lower shear modulus than the matrix is presented, where the minimum included angle reached by the arms of a dislocation while cutting the precipitate can be calculated as a function of the energy of the dislocation on either side of the precipitates/matrix interface.

373 citations


Journal ArticleDOI
TL;DR: In this paper, it is shown that the temperature on the fault plane can reach the melting temperature for short periods if the slip is sufficiently large and the displacement required to produce melting depends on the magnitude of the regional stress and also on the friction stress.
Abstract: Summary For simple models of the movement on a fault during an earthquake the temperature on the fault plane is shown to reach the melting temperature for short periods if the slip is sufficiently large. The displacement required to produce melting depends on the magnitude of the regional stress and also on the friction stress. If both stresses are one kilobar melting can occur for displacements as small as one millimetre. If, however, both stresses are ten bars melting is impossible for any observed displacement. It is estimated that the width of the melted zone could be between 2 mm and lcm. Melting on fault planes during earthquakes is not in disagreement with geological and geophysical observations, and suggests a new explanation for some mylonites. Melting may be important because the molten film rock formed on the fault may act as a lubricant and in the case of large earthquakes allow the release of almost all the elastic strain in the region of the shock. This would provide an important constraint in estimating the state of stress along a fault.

346 citations


Journal ArticleDOI
TL;DR: In this article, a model based on the thermally activated blocking of edge ⅓{11 3} dislocations was proposed, which may be due to the dissociation of the dislocation into two ⅙{20 3} partials.
Abstract: Electron Microscope Study of Pyramidal Slip {11 2} 〈11 3〉 in Magnesium We have investigated {11 2} 〈11 3〉 pyramidal slip in magnesium whose CRSS exhibits an anomalous dependence on temperature and increases between 270 and 375 K. Typical dislocation configurations were investigated by TEM in various temperature ranges. A model is proposed based on the thermally activated blocking of edge ⅓{11 3} dislocations. The blocking may be due to the dissociation of the ⅓{11 3} dislocation into two ⅙{20 3} partials. Our observations on magnesium are compared with those made on zinc and cadmium by other authors.

307 citations


Journal ArticleDOI
TL;DR: In this paper, the authors show that there is a transition from first to third mode at from 5 to 15 bars normal stress, a threshold at which Stick-SLIP PREDOMINATES.
Abstract: DETAILED LABORATORY MEASUREMENTS HAVE BEEN MADE ON THE FRICTIONAL CHARACTERISTICS OF WESTERLY GRANITE WITH GROUND SURFACES AND TO NORMAL STRESSES OF 1 KB. THESE MEASUREMENTS SHOW THAT FOR THIS TYPE OF SURFACE THERE ARE THREE TYPES OF SLIDING: CONTINUOUSLY STABLE, EPISODIC STABLE, AND STICK- SLIP. ALL THREE OF THESE MODES HAVE ALSO BEEN OBSERVED ON THE SAN ANDREAS FAULT IN CENTRAL CALIFORNIA. IN OUR LABORATORY EXPERIMENTS, THERE IS A TRANSITION FROM FIRST TO THIRD MODE AT FROM 5 TO 15 BARS NORMAL STRESS, ABOVE WHICH STICK-SLIP PREDOMINATES. STICK-SLIP, HOWEVER, IS ALWAYS PRECEDED BY A SMALL AMOUNT OF STABLE SLIP. IF THIS OCCURS ON A LARGE SCALE ON FAULTS, IT MAY BE A PROMISING PREMONITORY EFFECT FOR EARTHQUAKE PREDICTION. LOADING RATE IS FOUND TO INFLUENCE THE FRICTIONAL STRENGTH INVERSELY, WHICH MAY BE AN EXPLANATION FOR STICK-SLIP. STRESS DROPS WERE FOUND TO INCREASE WITH SHEAR STRESS, BUT NOT LINEARLY, SUGGESTING THAT RADIATION EFFICIENCY MAY INCREASE WITH STRESS DROP.

284 citations


Journal ArticleDOI
J. Gurland1
TL;DR: In this article, the initiation of fracture in the microstructure at room temperature was observed in tension, compression and torsion, and cracks formed in the carbide particles in a direction normal to the tensile strain imposed upon the particles by the deforming matrix.

280 citations


Journal ArticleDOI
TL;DR: In this paper, the tetragonal-monoclinic phase transformation in ZrO2 single crystals and polycrystals has been studied in both the forward and reverse directions and found to be martensitic.

163 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used the records of the Tottori earthquake of 1943 (M = 7.4, 35.5° N, 134.2° E, depth 10 km) about by a low-magnification seismograph at a relatively short distance to determine dynamics fault parameters such as the particle velocity and the effective tectonic stress.

Journal ArticleDOI
TL;DR: The most important factors which determine whether sliding will be unstable (stick-slip and earthquake-producing) or stable (stable sliding or fault creep) include mineralogy, porosity, effective confining pressure, temperature and thickness of fault gouge as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, the authors studied the migration of sub-grain boundaries during high-temperature testing of aluminium and showed that the migration contributes significantly to the overall strain rate of the specimen and that the stress dependence and temperature dependence are in accord with the macroscopic strain rate, and are strictly related to the deformation contribution from fine slip.
Abstract: Observations on the migration of sub-grain boundaries during high-temperature testing of aluminium are presented. It is shown that the migration contributes significantly to the overall strain rate of the specimen and that the stress dependence and temperature dependence are in accord with the macroscopic strain rate, and are strictly related to the deformation contribution from fine slip. The mobility of the sub-boundaries leads to a new understanding of the dynamic equilibrium of the sub-structure and its stability with respect to recrystallization. It further leads to the possibility of sub-boundaries acting both as effective obstacles to deformation and as sources of internal stress.

Journal ArticleDOI
TL;DR: The mechanism of crystal slip in olivine in peridotite xenoliths from alkalic basalts has been investigated by highvoltage (up to 1 MeV) electron petrography as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, the hardness of the cubic transition-metal carbides was examined as a function of the Knoop indenter orientation on the (001) surfaces of the carbides titanium, vanadium, zirconium, and niobium.
Abstract: Hardness has been examined as a function of indenter orientation on the (001) surfaces of the cubic transition-metal carbides titanium carbide, vanadium carbide, zirconium carbide and niobium carbide. To emphasize the observed anisotropy a Knoop indenter was used. Experiments have been performed in the temperature range -196 to 610$^{\circ}$C. The anisotropy curves obtained at each temperature have been analysed in terms of operative slip systems. Three different temperature regimes for the anistropy have been identified. These correspond to the {110} $\langle 1\overline{1}0\rangle $ slip systems for the low-temperature regime, the {111} $\langle 1\overline{1}0\rangle $ slip system for the high-temperature regime and a combination of these two systems for the intermediate-temperature regime. To explain this change in slip system it is proposed that an important temperature dependent change in bonding occurs. A qualitative model is suggested for this change in which an increased density of high mobility electrons increasingly screens the directional covalent bonds as the temperature is raised.

Journal ArticleDOI
TL;DR: In this paper, the focal process of the Rat Island earthquake of March 30, 1965, which occurred beneath the Aleutian trench, is studied on the basis of the long-period surface-wave data and the spatial distribution of the aftershocks.

Journal ArticleDOI
TL;DR: A simulation of the development of rolling texture in f.c. polycrystals has been performed, assuming that the deformation mechanism is multiple {111} 〈110〉 slip as mentioned in this paper.
Abstract: A simulation of the development of rolling texture in f.c.c. polycrystals has been performed, assuming that the deformation mechanism is multiple {111} 〈110〉 slip. The predicted crystallite orientation distribution functions for 40% and 80% reduction are in fair agreement with the experimentally determined texture of cold rolled copper. If deformation twinning is included as an additional deformation mode, following a simple strain accommodation criterion for twinning, a satisfactory agreement with the experimentally determined texture of cold-rolled copper-10% zinc is obtained.

Journal ArticleDOI
TL;DR: In this paper, a simple geometric model was proposed for the occurrence of transform faults and an aid to interpretation of structural patterns in the sea floor, showing that it is much more difficult for diverging plates to spread a kilometer of ridge than to slip a thousand of transform fault and the patterns observed at spreading centers might extend to lithospheric depths.

Journal ArticleDOI
TL;DR: In this article, high purity niobium crystals with a centre-triangle axial orientation were deformed in steps at 77°K and the lengths and orientations of the grid sides were determined, and using this information the amounts of slip on eight independent systems of {110} type were calculated.
Abstract: High-purity niobium crystals with a centre-triangle axial orientation were deformed in steps at 77°K. Each crystal was cut to a square cross-section and a reference grid applied to two adjacent surfaces before deformation. At each deformation step the lengths and orientations of the grid sides were determined, and using this information the amounts of slip on eight independent systems of {110} type were calculated. The results showed that most of the deformation occurred on the lightly stressed systems (011) [111] and (011) [111] with very little slip on the primary (101) [111] and conjugate (101) [111] systems. This analysis confirms earlier observations on high purity niobium deformed at low temperatures, which showed that (011) slip lines predominated (anomalous slip). The present data show that the conjugate Burgers vector is almost twice as active as the primary. In the earlier stages of deformation the straining proceeded by a series of small load drops, but later the curve became smoo...

Journal ArticleDOI
TL;DR: In this article, the authors simulated the fault growth process in a two-dimensional model and found that propagation velocity can range from sub-shear to 1.1 V s (the latter being not a limiting value).
Abstract: Earthquakes, at least the shallow ones, take place along pre-existing fault planes. The controlling factor is, therefore, friction, and the fault growth process resembles that of stick-slip propagation. We have simulated this process in a two-dimensional model. It is found that propagation velocity can range from sub-shear to 1.1 V s (the latter is not a limiting value).

Journal ArticleDOI
TL;DR: In this article, the deformation kinetics of polycrystalline titanium polycrystals were investigated in tension over the temperature range of 4.2 −650°K and showed that the rate controlling dislocation mechanism during the low temperature deformation of titanium is thermally activated overcoming of interstitial solute obstacles.

Journal ArticleDOI
TL;DR: In this paper, the phase transformations taking place in 2H SiC single crystals at temperatures as low as 400 C were studied, where some crystals transformed to a structure with one-dimensional disorder along the crystal c axis.
Abstract: Study of the phase transformations taking place in 2H SiC single crystals at temperatures as low as 400 C. Some crystals transformed to a structure with one-dimensional disorder along the crystal c axis. Others transformed to a faulted cubic/6H structure. The transformation is time and temperature dependent, and is greatly enhanced by dislocations. The transformation takes place by means of a slip process perpendicular to the c axis. Cubic SiC crystals were observed to undergo a solid-state transformation above 1400 C.

Journal ArticleDOI
TL;DR: In this article, the effects of slip band impingement and grain sile on the amount of intergranular and near-tlin boundarl cracking were examined in an easl crossslip material, copper, and a difficult cross-slip materials, brass.

Journal ArticleDOI
TL;DR: In this article, a mechanism similar to that of Li for edge dislocations is proposed for formation of screw dislocation from grain-boundary ledges, and several possible consequences with respect to macroscopic plastic deformation are discussed, the most important being incubation of slip at grain boundaries in the microstrain region.

Journal ArticleDOI
TL;DR: In this article, a general mathematical description of both elastic and plastically anisotropic materials is presented, and then several specific applications are considered in detail, including elastic-plastic wave propagation.
Abstract: Wave‐propagation effects induced in isotropic materials by either explosive or impact loading uniformly over a planar surface are much simpler than those produced in anisotropic solids in which significant transverse particle motion may occur. Such behavior in linearly elastic anisotropic solids has been investigated previously, and in the present work the analysis has been extended to include elastic‐plastic behavior. A general mathematical description of both elastically and plastically anisotropic materials is presented, and then several specific applications are considered in detail. For the case of an elastically isotropic solid that is plastically anisotropic with a single slip plane and direction, it is found that for certain orientations two plastic waves can be propagated, one of which is quasilongitudinal and the other is quasitransverse. For more general orientations there may be two quasitransverse waves and a single quasilongitudinal disturbance. These results approximate the behavior of a single‐crystal material of hexagonal symmetry, such as beryllium, for which effects of elastic anisotropy are small and slip occurs predominantly on the basal plane. Since there is a single spatial coordinate involved in planar wave propagation, the general equations describing elastic‐plastic wave propagation can be written in one‐dimensional finite‐difference form and solved numerically for arbitrary crystal structure and orientation. A number of specific examples are considered and compared with analytical solutions.

Journal ArticleDOI
TL;DR: In this article, a technique utilizing electroplating is described for the preparation of specimens for transmission electron microscopy, which show the relation between surface detail and internal structure, and the cleared channels in deformed neutron irradiated copper crystals have been correlated with surface slip steps indicating that the surface slip bands are a true representation of the bulk deformation behaviour.
Abstract: A technique utilizing electroplating is described for the preparation of specimens for transmission electron microscopy, which show the relation between surface detail and internal structure. The cleared channels in deformed neutron irradiated copper crystals have been correlated with surface slip steps indicating that the surface slip bands are a true representation of the bulk deformation behaviour. The slip steps show a uniform distribution of shear within the central region of the cleared channel, with a decreasing shear strain near the edges. The channel is, however, cleared of irradiation produced defects for approximately the full width of the slip step, indicating that the removal mechanism is relatively efficient. This and other features of the slip process are discussed in terms of the observations.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the deformation mechanism at low temperatures in zone-refined and annealed tantalum single crystals and concluded that the normal stress on the slip plane has an effect on the Peierls potential from the comparison of yield stresses for tension and compression with each other.

Journal ArticleDOI
TL;DR: The source mechanism of the San Fernando earthquake on February 9, 1971, was studied by utilizing seismic body waves, surface waves, and the static displacement and strain fields in this article.
Abstract: The source mechanism of the San Fernando earthquake on February 9, 1971, was studied by utilizing seismic body waves, surface waves, and the static displacement and strain fields. For computing the static fields due to a fault model with arbitrary dip and slip directions, Maruyama's equations are integrated numerically. Very strong asymmetries in displacement fields and complicated surface strain patterns are produced by the dip of the fault plane and inclination of the dislocation vector. The joint interpretation of the body and surface waves, near-field displacement, and far-field strain fields completely define all important source parameters. The mechanism of the San Fernando earthquake is a reverse fault (strike N70°W, dip 52°NE, slip 225°) with dimensions of 14 by 14 km. The average dislocation on the fault plane is 280 cm. The rupture started near the bottom of the fault plane and propagated toward the surface. Stress drop associated with faulting was Δσ = 70 bars, and the seismic moment was M0 = 16.4 × 1025 dyne cm.

Journal ArticleDOI
TL;DR: In this article, the velocity and temperature slip coefficients for general gas surface scattering kernels were evaluated by a variational method and the results were expressed in terms of a set of accommodation coefficients.
Abstract: The velocity and the temperature slip coefficients are evaluated for general gas‐surface scattering kernels by a variational method. The results are expressed in terms of a set of accommodation coefficients.

Journal ArticleDOI
TL;DR: The deformation and fracture of Zircaloy-4 and pure zirconium sheets having strong (0002) textures were studied under plane-strain compression at temperatures from 20° to 800°C as discussed by the authors.