Showing papers in "Acta Metallurgica in 1983"

TL;DR: In this paper, a planar double slip model was proposed to analyze the effect of material rate sensitivity on the formation of conjugate slip bands in planar planar crystal geometries.

TL;DR: In this article, a fracture mechanics approach has been used to predict fracture toughness increases due to crack deflection around second phase particles, based on a determination of the initial tilt and the maximum twist of the crack front between particles.

TL;DR: In this article, a simple model for single-slip and multiple-slink deformation is proposed, in which the crystal is considered as a composite consisting of hard dislocation walls of high local dislocation density which are separated by soft regions of low local dislocations density.

TL;DR: In this article, particle morphology and size were examined with respect to toughening by crack deflection in a series of hot-pressed silicon nitrides comprised of rod-shaped grains of various aspect ratios and a barium-alumino-silicate glass ceramic containing spherulites.

TL;DR: In this article, it has been shown that a large volume of data for the solubility of hydrogen in iron is affected by spurious surface conditions, which is consistent with the thermal activation of H atoms into less favorable octahedral sites as the temperature is increased.

TL;DR: In this paper, the development of precipitates in a range of nickel-base superalloys is investigated and the morphology is correlated with the size and sign of the γ γ′ misfit, measured using convergent beam electron diffraction.

TL;DR: In this article, the authors derived expressions for the rate of diffusional flow when the density of sinks and sources becomes small and when their mobility is limited by impurities, solutes, or precipitates.

TL;DR: A review of the literature concerning cavity nucleation as a result of plastic deformation indicates that at low temperatures there is a critical plastic strain required to nucleate a cavity as mentioned in this paper.

TL;DR: In this paper, the creep of porous KCl and of porous sucrose has been measured in the dry state, and saturated with aqueous solutions and with organic liquids, in a way which varies linearly with stress, and exponentially with temperature.

TL;DR: In this article, the free energy of crystallization is derived from regular solution models for the liquid and solid and is used, together with model-based estimates of the interfacial tension, to calculate the nucleation frequency from the classical theory.

TL;DR: In this paper, a computer simulation of a shear deformation of a model monoatomic amorphous metal has been performed, where the strain was applied incrementally, relaxing the structure at each step.

TL;DR: In this article, a probabilistic theoretical model was proposed to estimate transient inelastic shear strains in excess of 0.02 Tg for metallic glasses above 0.6 Tg.

TL;DR: In this paper, a model was proposed to describe the simultaneous changes in topological and chemical short range order during structural relaxation of metallic glasses, and the free volume and order parameter during isothermal and isochronal annealing were calculated.

TL;DR: In this article, six models for steady-state particle coarsening are presented in order to explain the shapes of experimentally obtained particle size distribution histograms, which indicate volume fraction effect on coarsing.

TL;DR: In this article, the near surface material of copper samples was examined by transmission electron microscopy (TEM) and STEM (scanning TEM) techniques after sliding tests of varying duration, and detailed orientation information was obtained with the aid of an improved technique which uses a minicomputer to analyse Kikuchi line patterns from individual cells or sub-grains.

TL;DR: In this article, the formation of macroscopic hydride stacks is investigated and the role of the texture of the alloy and of a stress acting on the basal planes in determining the orientation of the stacks is explained.

TL;DR: In this article, atomic probe field-ion microscopy has been used to study the decomposition of Ni-14 during isothermal aging at 823 K. The observed decomposition behaviour is interpreted in terms of the classical nucleation theory and by a modification of a theory due to Langer and Schwartz which considers coarsening already during the nucleation stage.

TL;DR: In this article, a phenomenological constitutive law for the steady creep of polycrystalline materials undergoing creep-constrained grain boundary cavitation is proposed based on micro-mechanical considerations.

TL;DR: The deformation of type 304 stainless steel produces a preponderance of strain-induced α′ (b.c.) martensite, which nucleates as stable embryos at micro-shear band or twin-fault intersections as proposed by Olson and Cohen as mentioned in this paper.

TL;DR: In this paper, it is shown that inelastic strain is a far more important parameter than time in determining the extent of acceleration of strain rate and that tertiary creep is produced by at least two competing strain-softening damage micromechanisms.

TL;DR: In this article, the authors examined hydrogen embrittlement in FeSi-and Ni-single crystals at low hydrogen pressures (10 mPa ⩽ pH2⩽ 100 kPa) and measured the crack tip opening angle α of a growing crack as a function of temperature, hydrogen pressure and rate.

TL;DR: In this paper, multislip and latent hardening tensile tests are performed on α-iron single crystals at room temperature, in order to check the assumption of crystallographic glide restricted to the {110} planes and the {112} asymmetric planes.

TL;DR: In this paper, the effects of multiple microalloy additions on the dynamic recovery and recrystallization behavior of austenite were investigated in a series of 0.05% C-l.

TL;DR: In this paper, the authors used time-of-flight neutron diffraction, using the General Purpose Powder Diffractometer at the IPNS (Intense Pulsed Neutron Source) at the Argonne National Laboratory, to measure residual stresses in deformed, polycrystalline Zircaloy-2.

TL;DR: In this article, a steady state nucleation frequency is established after a transient period, except for the y = 37.5 alloy, where the kinetics are dominated by growth on quenched-in nuclei.

TL;DR: In this paper, a small particle experiment to investigate the tetragonal to monoclinic ZrO 2 (martensitic) transformation was performed using a CuZrO2 model material prepared by internal oxidation.

TL;DR: In this article, the authors compared the near-threshold fatigue crack growth rate (FCGR) behavior in six alloy systems (iron, aluminum, copper, magnesium, nickel and titanium) and found that the value of ΔK th, eff was directly proportional to Young's modulus.

TL;DR: In this paper, an isothermal calorimetric analysis of devitrification kinetics of melt-spun alloys of the series (Au/100y/Cu/y/)77Si9Ge14 is presented.

TL;DR: In this paper, the hot-isostatic pressing of lead, tin and PMMA has been studied, using a rig which enables continuous measurement of density during a test, and the dominant mechanisms of densification are plasticity and creep.

TL;DR: The characteristics of dynamic recrystallization in χ sf μb becomes important; it makes Ni more like Cu than Al as discussed by the authors, and a change in the substructures observed both before and after dynamic re-stallization occurs at the same transition temperature.