Showing papers on "Annealing (metallurgy) published in 1970"
TL;DR: In this article, a mathematical model of annealing is proposed that takes account of both stress and structural relaxation, and the model fits the experimentally observed evolution of stresses during linear cooling, and suggests that the actual rate, at any given temperature, of structural relaxation is about 4 times lower than that of stress relaxation.
Abstract: Laboratory simulation of the industrial process of annealing sheet glass has yielded data on the genesis of stresses in initially stress-free glass. The experimental results differed from expectations based on classical annealing theory in that stresses began to develop in the annealing range even when the glass was being cooled at a constant rate, i.e. even in the absence of any changes of temperature gradients within the glass. Typically, these stresses account for 40% of the total residual stress in glass annealed according to a linear schedule. The remaining 60% are the well-known thermoelastic stresses that arise later in the annealing process from the decay of temperature gradients in the glass. The stresses observed to arise in glass as it is being cooled at a constant rate are attributed to volume relaxation effects which, in parts of the annealing range, generate stresses rapidly enough that they are not dissipated by stress relaxation. A mathematical model of annealing is proposed that takes account of both stress and structural relaxation. The model fits the experimentally observed evolution of stresses during linear cooling. It also suggests that (with the activation energies of stress and structural relaxation about the same) the actual rate, at any given temperature, of structural relaxation is about 4 times lower than that of stress relaxation.
143 citations
TL;DR: In this paper, the structure of reaction-sintered silicon nitride is studied using scanning electron and optical microscopy at various stages during nitriding, for a range of nit riding and compacting conditions.
Abstract: The structure of reaction-sintered silicon nitride is studied using scanning electron and optical microscopy at various stages during nitriding, for a range of nitriding and compacting conditions. The strength is then evaluated and interpreted in terms of the microstructure. It is found that fracture always occurs in a brittle manner by the extension of the largest pores. The effects of prolonged annealing in air above 1000† C on both the structure and strength are investigated. At 1400† C, cristobalite is formed. If the temperature is then maintained above 250† C, the strength is enhanced, but below this temperature the oxide layer cracks and reduces the strength.
135 citations
TL;DR: In this article, the channeling technique has been used to determine the lattice location of boron implanted into silicon by using the B11 (p,α) nuclear reaction.
Abstract: The channeling technique has been used to determine the lattice location of boron implanted into silicon by using the B11 (p,α) nuclear reaction. Approximately 30% of the boron lies on substitutional sites after a room‐temperature implantation of 3×1015/cm2. The substitutional content decreases with annealing temperature up to 700 °C and then increases at higher annealing temperature. This explains a reverse annealing behavior observed in the carrier concentration. Nearly all of the boron lies on substitutional sites after annealing at 1100 °C. The nonsubstitutional boron atoms do not occupy the normal tetrahedral interstitial sites. For annealing temperatures up to 500 °C they appear to lie along atomic rows, but they do not lie midway between row lattice sites. After higher‐temperature annealing their location appears less well‐defined.
102 citations
TL;DR: In this article, the relative grain boundary energy after annealing at 600°c is a function of amount of previous strain, but is always higher than that of material annealed at 1000°c.
Abstract: A thermal grooving technique has been used to measure the relative grain boundary energy of deformed and annealed copper. The relative grain boundary energy after annealing at 600°c is a function of amount of previous strain, but is always higher than that of material annealed at 1000°c. Annealing at 900°c leads to a return of the energy towards the equilibrium value. On the basis of the above results a mechanism is proposed for the action of grain boundaries as a sink for dislocations.
81 citations
01 Jun 1970
TL;DR: In this paper, the authors measured the resistance of austenite to plastic deformation (austenite flow stress) using a high temperature tensile apparatus and correlated the flow stress with the Ms temperature as determined magnetically during subsequent cooling.
Abstract: The resistance of austenite to plastic deformation (austenite flow stress) was measured using a high temperature tensile apparatus. The flow stress was then correlated with the Ms temperature as determined magnetically during subsequent cooling. In one part of the study, the flow stress of the austenite was varied only by work hardening the austenite, allowing the austenite composition, which is known to affect Ms, to be held constant. A decrease in Ms temperature with increasing austenite flow stress was observed. This observation was supported by the observation of a decrease in the amount of austenite transformed at 25°C. In the other part of the study, a series of alloy steels of different chemical compositions was tested. A decrease in Ms temperature with increasing austenite flow stress was again observed. Strengthening of austenite by plastic deformation was shown not to change the chemical driving force for transformation. The effect of deformation on Ms temperature thus results from its influence on either the nucleation or the growth process. While the effect of austenite deformation on martensite nucleation is uncertain, specific nucleation models can account for only approximately one-third of the nonchemical free energy change which accompanies transformation. A proposal, consistent with the observations, was made that the energy expended for the deformation of austenite during martensite plate growth could reasonably account for a substantial part of the nonchemical free energy change.
77 citations
TL;DR: In this article, the influence of several material and processing parameters on the dielectric trength of thermally grown films on silicon has been assessed by statistically analyzing the breakdown characteristics of a large number of MOS capacitor structures, which had been fabricated in various ways.
Abstract: The influence of several material and processing parameters on the dielectric trength of thermally grown films on silicon has been assessed. This was accomplished by statistically analyzing the breakdown characteristics of a large number of MOS capacitor structures, which had been fabricated in various ways. Although the results of this investigation are only qualitative, they clearly demonstrate that the effective breakdown strength of these films is strongly dependent on: purity, structural perfection and thickness; the presence of a passivating phosphosilicate glass layer; the presence and reactivity of the metal electrode; and, the duration of the post‐ metallization heat treatment. The morphology of certain micron‐size defects which develop in the MOS structure during annealing is described in some detail, since these faults are apparently responsible for oxide shorting in some instances.
77 citations
TL;DR: In this paper, the authors used both scanning and transmission electron microscopy (TEM) to investigate the structural damage caused by annealing of implanted silicon, including dislocations, rod-like structures, micro-twins, semi-polycrystalline material, misoriented zones, etc.
Abstract: Silicon specimens were irradiated with Ne+, B+, P+ and Sb+ ions. The energy was 80kV, and the doses in the range 1013 to 1016 ions/cm2. The resulting structural damage was investigated by both scanning and transmission electron microscopy. The SEM electron channelling pattern method was used to determine the variation of gross damage with ion type, dose, depth below the surface, and annealing treatment. The TEM method was used to study the detailed nature of the defects formed by the annealing. These included dislocations, rod-like structures, micro-twins, semi-polycrystalline material, misoriented zones, etc. The results are briefly compared with known electrical properties of implanted silicon, and some correlations noted.
71 citations
TL;DR: The magnetic properties of the hexagonal intermetallic compounds involving the rare-earth and 3D transition metals have been reported in the literature as mentioned in this paper, and the most important factors determining the coercive force appear to be the chemical composition, the cooling rate, the alignment of the SmCO 5 -rich phase, and the annealing treatment.
Abstract: The magnetic properties of the hexagonal intermetallic compounds involving the rare-earth and 3d transition metals have been reported in the literature. These alloys look promising as fine-particle permanent magnets. A large number of samples in the system SmCo 5-x Cu x were prepared by induction melting under a protective atmosphere, and annealed at various temperatures. An outstanding feature of these alloys is their high intrinsic coercive force. After annealing at low temperatures, they show coercive forces above 20 kOe and an energy product of about 8 × 106G.Oe. The most important factors determining the coercive force appear to be the chemical composition, the cooling rate, the alignment of the SmCO 5 -rich phase, and the annealing treatment. Examination by electron microscopy and electron probe techniques suggests a spinodal decomposition of a supersaturated solid solution into two phases, one rich in SmCo 5 and the other rich in SmCu 5 .
55 citations
TL;DR: In this paper, the preparation and properties of thin polyethylene films deposited by vacuum evaporation were described. But the results were limited to a single crystal orthorhombic structure with lattice parameters a = 7.40 A and b = 4.95 A.
50 citations
TL;DR: The physical and electrical properties of aluminum oxide films deposited on silicon by rf sputtering from an alumina target in an argon atmosphere were investigated as a function of sputtering power density in the range from 0.5 to 3 W/cm2 as discussed by the authors.
Abstract: The physical and electrical properties of aluminum oxide films deposited on silicon by rf sputtering from an alumina target in an argon atmosphere were investigated as a function of sputtering power density in the range from 0.5 to 3 W/cm2. The deposition rates ranged from 20 to 80 Aa/min. The density, index of refraction, and dielectric constant of the films increased while the etch rate decreased with increasing power density. The surface charge at the aluminum oxide‐silicon interface was typically larger than 1012 e/cm2. This charge increased with increasing sputtering power density and could be reduced to by annealing. The films exhibited trapping instabilities at room temperature but no polarization was observed under bias‐temperature stress. The characteristics of composite layers of thermally grown silicon dioxide and sputtered aluminum oxide layers on silicon were also investigated and found to exhibit low surface charge densities, no hysteresis, and a "contact potential" as well as charge stored at the interface between the two insulators.
45 citations
TL;DR: In this article, the optical and electrical properties of thin films of amorphous germanium are investigated as a function of the conditions of deposition, and the results are compared with the results of annealing experiments and interpreted in terms of varying amounts of imperfections.
TL;DR: In this article, arc-plasma spray deposition has been successfully applied to fabrication of planar ferrite microwave integrated circuits, and commercial sintered microwave ferrites were deposited at rates up to 2 mils/min on 1 sq in. dielectric substrates.
Abstract: The arc‐plasma spray deposition has been successfully applied to fabrication of planar ferrite microwave integrated circuits. Powdered commercial sintered microwave ferrites were deposited at rates up to 2 mils/min on 1 sq in. dielectric substrates by arc‐plasma spray deposition. Process controls produced densities >99% theoretical and also maintained stoichiometric agreement between deposited films and starting material. Annealing expanded <0.1 μ grains to useful sizes of 1 to 20 μ and controlled cation distribution. Special annealing techniques were necessary for ferrites having volatile products such as Ni–Zn compounds. Magnetic and microwave properties of several deposited Mg–Mn ferrites and CeYIG agreed closely with bulk values. Remanence ratios up to 0.87 were noted. Practical application of arc‐plasma deposition required material compatibility studies at high temperature. These considerations often superseded microwave properties as criteria for material section.
TL;DR: In this article, a number of 1ω cm n-type silicon substrates have been implanted with boron at room temperature, and samples from these substrates were annealed at predetermined temperatures between 600°K and 1400°K.
Abstract: A number of 1ω cm n-type silicon substrates have been implanted with boron at room temperature. Samples from these substrates were annealed at predetermined temperatures between 600°K and 1400°K and four-probe electrical measurements and transmission electron micrographs were taken. An attempt has been made to correlate the two studies and it is possible to explain the observed annealing behaviour in terms of precipitation during recrystallization, and migration of defects.
01 Mar 1970-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this article, the formation of the semi-insulating layer in the junction and its subsequent variation of thickness with annealing are attributed to deep diffusion of defects during the implantation or subsequent anneal, which produces compensation to the depth where the concentration of defects equals the substrate impurity concentration.
Abstract: Doping of semiconductors by implantation of high-energy ions creates lattice damage which in general must be removed by annealing to form good qualityp-n junctions. Implantation of zinc or cadmium ions inton-type gallium arsenide substrates held at 400°C produces ap-n junction after the samples are annealed at elevated temperature (≥500°C for zinc, ≥600°C for cadmium). However, the resulting junctions are not abrupt; they contain a semiinsulating (I) layer and have ap-i-n structure. The thickness of the semiinsulating layer changes with annealing. For example, an implant of 1.3×1015 per sq cm, 20 kv, Zn+ ions produced a junction with an I layer of 28 μ thickness after annealing for 10 min at 600°C. An identically implanted sample, annealed for 10 min at 900°C, had an I layer thickness of 120 μ. A similar increase in I layer thickness with annealing was observed for samples implanted with 20 kv Cd+ ions at 400°C. Implantation of Zn+ and Cd+ ions into GaAs substrates held at room temperature produced junctions with much thinner I layers after annealing than those observed for the 400°C implants. The formation of the semiinsulating layer in the junction and its subsequent variation of thickness with annealing are attributed to deep diffusion of defects during the implantation or subsequent anneal, which produces compensation to the depth where the concentration of defects equals the substrate impurity concentration. The compensating centers are thought to be arsenic vacancy-substrate dopant atom complexes.
TL;DR: In this paper, the partial pressure dependence of doping level in the epitaxial layers of silicon is measured over a wide range of dopant partial pressures at low doping levels, solid solutions of boron and arsenic obey dilute solution theory.
TL;DR: In this article, the defect annealing time at the threshold of the crystalline to amorphous transition at 173°K for 1 μA/cm2 was calculated for the Si divacancy, following room temperature and 85°K implants of 400-keV B11 or Sb121 ions.
Abstract: Recent results have reported a strong implantation-temperature dependence between 125°K and room temperature for lattice disorder produced by 200-keV B implantation into Si. Using our previous annealing model incorporating implant temperature and dose rate, we have calculated a characteristic defect annealing time at the threshold of the crystalline to amorphous transition at 173°K for 1 μA/cm2 and find that it agrees very closely with that for neutral vacancy annealing. In addition, we have made measurements of the 1.8μ infrared absorption band, characteristic of the Si divacancy, following room temperature and 85°K implants of 400-keV B11 or Sb121 ions. Very few divacancies are observed immediately after 85°K implants, but annealing growth of divacancies occurs between 150 and 300°K yielding a density almost equal to that for the same ion Ruence at 300°K. These results strongly suggest that below 300°K neutral vacancy motion and trapping control both the implantation-temperature dependence of l...
01 Jan 1970
TL;DR: In this article, the effects on the reordering processes of varying the material parameters and the irradiation conditions are considered, and suggestions are made to minimize the effects of transient annealing on devices.
Abstract: The annealing of radiation-produced defects in semiconductor devices is discussed briefly for60Co gamma-ray and 1-MeV electron damage, and in detail for fast-neutron damage. The effects on the reordering processes of varying the material parameters and the irradiation conditions are considered. Transient annealing of neutron damage near room temperature has been investigated for a wide variety of devices, and the data are presented in generalized form to increase their usefulness to device and circuit designers. Based on the experimental results, physical models are suggested for the reordering processes which occur during the annealing of neutron damage. Electron density is shown to be the most important factor governing the rate of transient annealing. Annealing factors are estimated for very early times (1 µs) following neutron exposure. Suggestions are made to minimize the effects of transient annealing on devices.
TL;DR: The photoelectronic properties of CdS successively implanted with 1.0, 0.5, and 0.3 MeV P+ ions versus annealing cycles were studied as mentioned in this paper.
Abstract: The photoelectronic properties of CdS successively implanted with 1.0‐, 0.5‐, and 0.3‐MeV P+ ions versus annealing cycles were studied. Diodes thus formed were highly photosensitive, with photoconductive gains between 102 and 104. Yellow electroluminescence was observed at 77°K. Short annealing creates centers with a sheet resistance thermal activation energy of 0.13 eV. Prolonged annealing creates states 0.75–0.8 eV below the band edge.
TL;DR: The annealing textures in Zircaloy tubing are more complex than those reported for rolled and annealed zirconium or titanium sheet as mentioned in this paper, due to the variations in deformation temperature, degree of deformation, and deformation method.
TL;DR: In this paper, the effect of low-temperature annealing on the yield stress of niobium following neutron irradiation was studied, and it was shown that post-irradiation denoising strengthened the defect clusters as barriers to dislocation motion by as much as a factor of two.
Abstract: The effect of low-temperature annealing on the yield stress of niobium following neutron irradiation was studied. The initial increase in yield stress upon irradiation was sensitive to the interstitial carbon content. A further increase in the yield stress (“radiation-anneal hardening”) was observed after two-hour anneals near 150 and 300 °C. When the annealing temperature was raised above 400 °C, the yield stress gradually recovered toward the preirradiation value. Changes in the density and size of the radiation-produced defect clusters were determined by transmission electron microscopy following post-irradiation anneals. An analysis of the observed hardening based on a dispersed barrier model and the density and size of defect clusters indicated that post-irradiation annealing strengthened the clusters as barriers to dislocation motion by as much as a factor of two. Previous resistivity and internal friction measuremements have shown that interstitial oxygen and carbon in irradiated niobium migrate to the defect clusters at the temperatures near 150 and 300 °C, respectively. Thus, the radiation-anneal-hardening peaks at these temperatures are attributed to the trapping of oxygen and carbon, respectively, at defect clusters. There is a reduced tendency for dislocation channeling (i.e., defect cluster removal by slip dislocations) in radiation-anneal-hardened niobium, suggesting that indeed the clusters have been strengthened.
TL;DR: A series of conductivity measurements were made on single crystals of Cu2O from 20 to 840 °C to explain the various activation energies which appear at different temperatures and oxygen pressures as discussed by the authors.
Abstract: A series of conductivity measurements were made on single crystals of Cu2O from 20 to 840 °C to explain the various activation energies which appear at different temperatures and oxygen pressures. ...
TL;DR: In this paper, it has been conclusively demonstrated by the observations of dark field images that the so-called K -state, which appears on annealing at a low temperature after quenching from a high temperature, is characterized by the inhomogeneous formation of very small Fe 3 A1 type ordered particles of 20∼30A in diameter in the matrix α-solid solution.
Abstract: Transmission electron microscopy and diffraction study and electrical resistivity measurement of iron-aluminium alloys containing 17.87 to 21.54 at.% aluminium have revealed the nature of the “ K -state” in this alloy system. It has been conclusively demonstrated by the observations of dark field images that the so-called “ K -state”, which appears on annealing at a low temperature after quenching from a high temperature, is characterized by the inhomogeneous formation of very small Fe 3 A1 type ordered particles of 20∼30A in diameter in the matrix α-solid solution. The specimens slowly cooled from a high temperature and isothermally annealed have also been examined to compare the structures with those showing the “ K -state”. A discussion on the equilibrium phase diagram of the iron-aluminium solid solution is given.
TL;DR: In this paper, a cold-drawn Al/1 wt % Ni alloy irradiated to 1 × 1022 fast neutrons/cm2 (E > 0.821 MeV) and > 2 × 10 22 thermal neutrons /cm2 at 60 °C in an aqueous environment contained polyhedral voids up to 550 cm 3 and a fine solid precipitate of transmutation-produced silicon.
TL;DR: In this article, large Widmanstatten particles of θ phase in an Al-5% Cu alloy were grown by annealing for long times at 464°C.
TL;DR: In this article, the annealing behavior of quenched condensed metal films, which are evaporated in vacuum at liquid helium temperatures, was investigated. And the results showed that the phonon drag part of thermopower Sg is completely suppressed.
Abstract: For the first time it is reported on the annealing behaviour of the thermopower of quenched condensed metal films, which are evaporated in vacuum at liquid helium temperatures. The measurements concern Pb- and Sn-films, Au- and Cu-films as well as Au-films with small amounts of Fe, and Bi-films between 2 and 300 °K. It is shown that in all quenched films the phonon drag part of thermopower Sg is completely suppressed. In Pb and Sn the part of thermopowerSe caused by electron diffusion is not changed remarkably by quenching, whereas in Au- and Cu-films it is much greater than in bulk material up to 250 °K. Annealing at higher temperatures leads to an irreversible decrease ofSe. The well known giant thermopower due to Fe-impurities in gold is very much reduced by quenching. The characteristic minima appear again after annealing of these films. Amorphous Bi-films have thermopowers which are comparable with those of Pb and Sn. After crystallisation the negative thermopower is much greater and increases with increasing temperature of annealing.
TL;DR: In this paper, the effect on the optical absorption edge and free carrier region of GaAs and GaP thin film and bulk samples have been irradiated with neutron fluences of 1018 nvt.
Abstract: GaAs and GaP thin film and bulk samples have been irradiated with neutron fluences of 1018 nvt and the effect on the optical absorption edge and free carrier region determined. In the case of both GaAs and GaP films, which exhibit bulk or near bulk optical properties before irradiation, large optical absorption edge shifts of ∼0.3 and ∼1.5 eV, respectively, are caused by the neutron bombardment. These optical absorption edge shifts can be ``annealed out'' by high‐temperature vacuum annealing; in the case of the GaAs films, isochronal annealing points to a Frenkel‐pair annihilation mechanism. Bulk samples of GaAs and GaP, similarly irradiated, exhibit smaller optical edge shifts than the films with substantially different quantitative behavior. High‐temperature vacuum annealing of the bulk samples also results in a recovery of normal optical properties.