Showing papers in "Materials Science and Engineering in 1971"

TL;DR: In this paper, a model for superplastic deformation is proposed that is based on grain boundary sliding and is controlled by the rate of deformation of the grain interior, and a comparison is made of the proposed model and the various creep mechanisms in order to reveal the ranges of conditions over which each mechanism predominates and how the various mechanisms are related one to another.

TL;DR: In this paper, the fracture toughness of glass sphere filled epoxy and polyester resins was studied as a function of interfacial strength and volume fraction of glass, and the toughness was determined using a tapered cleavage specime.

TL;DR: In this paper, a thermodynamic and kinetic model is developed which predicts the high temperature behavior of cracks under conditions of tensile and compressive stress, and expressions for the time to rupture following the propagation of Griffith cracks by lattice diffusion, surface diffusion and vapour phase transport.

TL;DR: In this article, the authors investigated the role of vacancies in the nucleation of silicon precipitates and found that the dislocation loops are formed by condensation of vacancies and the loops disappear and silicon atom clusters become visible in the second stage where the resistivity decreases rather slowly.

TL;DR: In this article, the relationship between strain rate, flow stress and deformation mode for single crystals of a precipitation-hardened nickel-base alloy has been investigated over the temperature range of 1400° to 1850° F and strain range 10 −1 to 6 × 10 3 %/min.

TL;DR: Using a gravity segregation technique it has been shown that the eutectic composition in the gold-silicon system occurs at 17.9 at. % silicon as mentioned in this paper, which is the highest known ratio of silicon to gold.

TL;DR: In this paper, it was shown that the ratio of yield point to Young's modulus is between about 1 30 and 1 60 for nearly all glassy polymers, and when a given polymer is tested under a variety of conditions a variable which increases the modulus also increases the yield point.

TL;DR: In this paper, a relationship σ 2 − σ 1 =K e L m m was developed which relates the yield drop and the Luders strain e L during discontinuous yielding.

TL;DR: In this paper, the influence of hydrogen pressure on the degree of hydrogen-environment embrittlement was determined on unnotched and notched specimens of AISI Type 310 stainless steel, ASTM A-302 and Inconel 718.

TL;DR: In this paper, a new equation has been developed to fit the experimental data for Armco iron at room temperature, in which there are parameters whose variation with grain size parallels that of similar parameters in the Hall-Petch relation for the lower yield stress.

TL;DR: The formalism of reaction rate theory with respect to stress dependence and activation area for activated dislocation motion is reviewed in this article, where the forward and backward activation areas are clearly distinguished and shown to be in general quite different.

TL;DR: In this article, the effect of concurrent straining on the rate of spheroidization of a high-purity eutectoid composition steel was studied, and it was found that concurrent strain rate and temperature were a function of both strain rate, e dot, and temperature, T of the form e dot me Q/RT.

TL;DR: In this article, the authors studied the impact of the passage of a number of dislocations on a single slip plane from one grain to the adjacent grain across the grain boundary.

TL;DR: In this article, a quantitative model of diffusion and concomitant hydride growth is used to explain the observed distribution of hydrides precipitates during the isothermal corrosion of Zircaloy.

TL;DR: The influence of viscous drag on dislocation motion in close-packed metals is examined in this article, where three experimental measurements of the viscous drifts are discussed, i.e. internal friction, strain rate versus stress, and stress-time-displacement measurements.

TL;DR: In this paper, the following means of producing duplex crystals are briefly reviewed: directional solidification of eutectic, off-eutectical, monotectic and peritectic alloys; directional control of eUTectoid decomposition and discontinuous precipitation; continuous precipitation.

TL;DR: In this article, an X-ray diffraction determination of the carbide phase strain as a function of the overall strain on the tension side of bent strips was carried out on four WC-Co alloys with Co contents of from 6 to 15 weight percent.

TL;DR: In this paper, it was shown that it is possible to have an increase, decrease, or no change in the temperature dependence of the yield stress, depending upon a low, intermediate or high interstitial concentration, respectively.

TL;DR: The principal features of plastic deformation in materials which form Luders bands are reviewed in terms of dislocation mobility and are related to the static (or near static) stress-strain curve as mentioned in this paper.

TL;DR: In this article, the deformation dynamics of polycrystalline titanium with 0.2% O eq. total interstitial content were investigated over the range of 77° K to 350° K by incremental loading and temperature-change creep tests.

TL;DR: In this paper, the authors examined the unidirectional solidification characteristics of nickel-base superalloys and found that dendritic growth can be suppressed by steep thermal gradient and low solidification rate.

TL;DR: In this article, the internal friction of bulk polyoxymethylene, from 4.2° to 300°K, was investigated using an inverted torsion pendulum at 1-3 Hz.

TL;DR: In this article, a digital computer program has been written in FORTRAN for computing and plotting stereographically the geometrical features of martensitic transformations, based on the theoretical formulation of Bowles and Mackenzie.

TL;DR: In this paper, the critical void size, nucleation barrier and void incubation time have been derived for voids which form at two-and three-grain junctions under an electromigration-induced vacancy supersaturation.