Showing papers in "Materials Science and Engineering in 1983"

TL;DR: In this paper, the effect of two heat treatments on the creep behavior of CMSX-2, a recently developed nickel-base single-crystal turbine blade alloy, was investigated in the temperature range 760-1050 °C.

TL;DR: A review of the literature on the ductile fracture of metals and alloys reveals almost immediately that the majority of investigations approach the topic from a fracture mechanics point of view and that papers based entirely on microstructural research are rare as discussed by the authors.

TL;DR: In this paper, it was shown that dislocation cells formed in coplanar arrays should transform into tilt walls with or without some twist component, such that the axis of relative misorientation is roughly parallel to the original edge dislocations.

TL;DR: In this article, a well-dispersed and uniformly packed TiO2 powder compacts were used to achieve low temperature sintering in ultrafine, well-distributed, and uniform packed compacts.

TL;DR: In this article, a study of the elevated temperature slow plastic flow properties of the B2 aluminide Fe-39.8at.% Al was undertaken and the results revealed that the extrusion temperature affected the active deformation mechanisms.

TL;DR: Crack nucleation mechanisms at plastic strain amplitudes of 10−3 and 10−4 are reported for polycrystalline pure copper in this paper, where the dislocation structures consist of persistent slip bands (PSBs) and loop patches.

TL;DR: In this paper, the adiabatic shear bands formed by 7.62 mm armour-piercing bullets were examined using optical and transmission electron microscopy, and the rapid cooling of highly deformed shear band was of the order of 10 7 °C s −1.

TL;DR: In this article, a new method for the analysis of multiaxial residual stress states is presented, which is based on high resolution neutron diffraction, analogous to X-ray stress analysis, but the use of neutrons instead of X-rays allows to analyse the stress distributions also in the interior of technical components in a non-destructive way.

TL;DR: In this paper, the precipitation behavior of nine casts of AISI type 316 steels, with aging temperatures ranging from 550 to 815°C and times up to 120 000 h has been studied using a newly developed X-ray internal standard technique.

TL;DR: The precipitation behavior of AISI type 316 stainless steel is reviewed in this article, where the crystal structure, composition, occurrence and characteristics of the major precipitates found in this steel (M23C6, σ, λ and η) are described.

TL;DR: In this paper, conditions of pore separation from grain boundaries during sintering are analyzed and it is shown analytically that a minimum intrinsic and solute drag force is required to prevent pore extraction.

TL;DR: The microstructures of a range of metallic powder compacts obtained by dynamic, or shock wave, compaction have been examined in an attempt to elucidate the processes leading to bonding.

TL;DR: In this paper, the authors studied the effect of strain-controlled fatigue deformation on serrations in 304 austenitic stainless steel and found that the lower critical temperature for the appearance of serrations was lower than that during monotonic tensile deformation.

TL;DR: In this article, a model which incorporates a simpl heat transfer analysis and material properties such as the strain-hardening rate, the temperature dependence of the flow stress and the strain rate sensitivity of flow stress was developed in order to establish the tendency towards localized flow.

TL;DR: In this article, low cycle fatigue tests on cast cobalt superalloy MAR-M 509 were conducted at various temperatures from 20 to 1100 °C in laboratory air using sawtooth cycling under plastic strain control at a constant total strain rate.

TL;DR: In this paper, the authors extended the earlier analysis of predicting the creep class behavior of a particular solid solution alloy to take into account the situation in which the contributions of solute atom-dislocation interactions such as the Suzuki and the Fisher interactions to the dragging force acting on the dislocations during glide are significant and comparable with that provided by the Cottrell-Jaswon interaction.

TL;DR: In this paper, the authors investigated the creep of high purity iron at low stresses (0.1-3.5 MPa) over a homologous temperature range T T m of 0.40-0.54 using the helicoid specimen technique.

TL;DR: In this article, single crystals of aluminum are deformed in shear at a number of constant strain rates in the range 10−5-1600 s−1 and to strains of about 20%.

TL;DR: In this paper, the stiffness constants Cik of the following nickel-base alloys were measured: NiAl solid solutions with aluminium contents up to 8 at., Nimonic alloy PE16 and an experimental alloy with the same composition as the matrix of fully precipitated PE16.

TL;DR: In this article, the cross-slip of dislocation groups may be an important work-hardening mechanism and evidence that supports this view is documented in this paper, and observations of similar structures in plastically deformed crystals are reviewed.

TL;DR: In this paper, the effect of prestraining on the J Ic value for AISI 4340 steel was examined, and the results confirm that crack tip blunting due to mobile dislocation mechanisms is responsible for the significant increase in toughness at low values of pre-straining.

TL;DR: In this paper, the ion nitriding behavior of several low alloy steels, U.S. Steel T1 type A, AISI 4140, A ISI 6150 and Nitralloy 135M, has been examined under varying process conditions using microhardness-depth correlations, friction and wear measurements, optical microscopy and transmission electron microscopy.

TL;DR: In this article, the authors compared solution-annealed samples of various prior austenite grain sizes with samples given the additional sensitization treatment, and found that a finer grain size improves the resistance to hydrogen cracking regardless of the failure mode.

TL;DR: In this article, the authors investigated the influence of axial load on mode III fatigue crack growth in cylindrical circumferentially notched AISI C1018 steel specimens.

TL;DR: In this article, it was shown that the thermally activated deformation of zirconium and titanium is not controlled by the overcoming of individual interstitial solute atoms by dislocations as usually proposed.

TL;DR: In this article, an additional parameter dealing with the effect of extensive solubility on the glass-forming ability is incorporated with the existing parameter, the reduced liquidus temperature, and the results are reasonably consistent with experiments.

TL;DR: In this article, it has been found that when the tensile axis is orthogonal to the prestrain axis, the dislocation cell structure of the pre-strain becomes unstable and dissolves.

TL;DR: In this article, the influence of oxidation on the high temperature low cycle fatigue behavior of the cast cobalt superalloy MAR-M 509 was studied in two ways; first, the oxides forming on fatigue specimens were identified and, secondly, tests under vacuum were carried out at 900 °C.

TL;DR: In this article, the primary recrystallization of a commercial nickel-base superalloy, Nimonic 115, has been investigated using light optical microscopy and hardness testing; the reasons for a high apparent value of activation energy so obtained are discussed.