bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Densification Mechanisms of Liquid-Phase Sintering
Authors: Lee Sung-Min , Kang Suk-Joong L. 
Published: February 2022

Abstract
The contact flattening between grains has long been considered to be the densification mechanism during liquidphase sintering. Recently, however, we proposed pore filling as being the major mechanism. In this investigation, we critically examine the two densification mechanisms by calculating their contributions to the sintering. The calculation shows that the contact flattening can be operative at the early stage for systems with a dihedral angle of zero degrees. However, its contribution to grain shape change and compact shrinkage is insignificant compared with that of the grain growth. A consideration of microstructures in real systems further suggests that the contribution of contact flattening is much less than the calculated value and is negligible from the beginning of the liquid-phase sintering. In fact, pore filling, which is induced by grain growth, appears to be essentially the only densification mechanism. An exemplified calculation of densification kinetics by pore filling is also presented and its implication discussed.
Phase Transformation of a Dual Phase Al–Fe Alloy Prepared by Mechanical Alloying
Authors: Zhou Fei , Lück Reinhard , Lu Ke , Rühle Manfred 
Published: February 2022

Abstract
A metastable Al90Fe10 (at.%) alloy, composed of a supersaturated solid solution of face-centred cubic (fcc) Al(Fe) and an amorphous phase matrix, was prepared by mechanical alloying of a mixture of Al and Fe elemental blends. The thermally induced microstructural evolution in the dual phase alloy was characterized by X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, and magnetothermal analysis. On continuous heating two stages of solid state phase transformation occurred: (i) a polymorphous crystallization of the amorphous phase to a metastable crystalline Al6Fe that structurally stabilizes over a temperature range of about 200 K, and (ii) a eutectoid decomposition of the crystalline Al6Fe into the equilibrium phases of Al13Fe4 and fcc Al(Fe). Thermodynamic and kinetic analyses of the observed phase transformation processes were given. The formation of the dual phase alloy in the as-milled state and the phase transitions can be illustrated by a hypothetical free energy diagram, implying the dual phase structure facilitates the polymorphous crystallization of Al6Fe.
Discrete Element Simulation of Ceramic Powder Processing
Authors: Greil Peter , Cordelair Jens , Bezold Alexander 
Published: February 2022

Abstract
Discrete element modeling (DEM) was applied for simulating the powder packing dynamics during electrophoretic deposition of electrostatically stabilized ZrO2 (powder size 1 μm) and tape casting of BaTiO3 (powder size 0.3 μm) stabilized by polymer adsorption. The results indicate that a transition zone of ordering is supposed to exist ahead of the growth front of the solid sediment during electrophoretic deposition. Local variation of the shear rate in the tape casting process with increasing distance from the blade gives rise for the generation of particle clusters under low shear, and cluster disintegration (shear thinning) under high shear conditions. Thus, DEM simulation provides a detailed insight into local variations of particle interaction processes during consolidation which can be used for optimization of the shaping process of colloidal ceramic powder suspensions.
Strain Relaxation and Internal Friction in the Range of the Glass Transition
Authors: Ege Michael , Ulfert Wolfgang , Kronmüller Helmut 
Published: February 2022

Abstract
For the investigation of structural relaxation near the glass transition quasistatic creep after-effect measurements have been performed on the alloy Zr65Cu17:5Ni10Al7:5 which shows a large stability above the glass temperature T
g. By a separation of anelastic local atomic rearrangements and viscous long-range diffusion processes the thermal activation parameters of both processes could be determined from Arrhenius diagrams. Below T
g = 606 K an activation enthalpy of 2.1 eV and above T
g an activation enthalpy of 5.6 eV has been determined. For a quantitative description of these relaxation phenomena a new dynamic model is developed which takes into account the continuous formation and annihilation of relaxation centers near T
g. From measurements of the internal friction after rapid temperature changes it could be shown that extended relaxation centers present above T
g become instable below T
g and are split up by diffusion processes above 585 K, however, disappear spontaneously below 580 K.
Epitaxial Growth of Metals on (100) SrTiO3: The Influence of Lattice Mismatch and Reactivity
Authors: Wagner T. , Polli A. D. , Richter G. , Stanzick H. 
Published: February 2022

Abstract
The model system Me/(100) SrTiO3 (Me: Pd, Pt, Cu, Ni, Cr, Mo, Nb, and Al) was used to show that there exists a simple correlation between the formation of particular epitaxial orientations, the lattice mismatch between metal and SrTiO3, and the oxygen affinity of the metal. The growth of the metal films on the (100) SrTiO3 surface was studied by reflection high-energy electron diffraction. Most metals (Pd, Pt, Ni, Nb and Al) grew with the following epitaxial orientation relationship on the SrTiO3: (100) SrTiO3 | | (100) Me, [001] SrTiO3 | | [001] Me. A second epitaxial orientation relationship was detected for Cr and Mo: (100) SrTiO3 | | (100) Cr, Mo, [001] SrTiO3 | | [011] Cr, Mo. For Mo, this orientation was detected only at very high growth temperatures. For each of the epitaxial orientation relationships, the substrate and film planes of four fold symmetry were parallel. Besides the second epitaxial orientation relationship, a third epitaxial orientation relationship was detected for Mo at growth temperatures below 900 K: (100) SrTiO3 | | (110) Mo, [001] SrTiO3 | | [001] Mo. In contrast to all other metals under investigation, Cu grew with a (111) fiber texture on the (100) SrTiO3 surface. The appearance of the first two epitaxial orientation relationships can be interpreted with a simple relationship between the metals’ oxygen affinities and the lattice mismatches with SrTiO3. This relationship can be used for other metals to predict epitaxy on the (100) SrTiO3 surface.
Metastable Al–Nd–Ni and Stable Al–La–Ni Phase Equilibria
Authors: Gödecke Tilo , Sun Wensheng , Lück Reinhard , Lu Ke 
Published: February 2022

Abstract
Fast cooling leads to the formation of metastable phase equilibria in the Al-rich part of the Al –Nd –Ni system. The metastability is characterized by a suppressed formation of the ternary τ
1 phase. The stable Al –La – Ni system is similar to the Al –Nd– Ni system but without the existence of a τ
1 phase. For comparison, this system is investigated. The results are represented as isopleths, liquidus surface projections, and reaction schemes. A fine-grain ternary eutectic morphology with enhanced hardness can be produced by rapid cooling in both ternary systems; the ideal chemical composition of this morphology depends on the cooling rate.
Calculation of Phase Equilibria in Candidate Solder Alloys
Authors: Kattner Ursula R. , Handwerker Carol A. 
Published: February 2022

Abstract
New solder alloys are being developed for electronic assemblies as replacements for traditional Pb-containing solder materials as a result of international pressure to remove Pb from the waste stream. In the transition period from Pb-containing to Pb-free solder alloys, component leads and copper interconnections on circuit board will continue to be pre-tinned with a Pb-containing solder to improve solderability. Phase equilibria information is needed for the evaluation of candidate Pb-free solder alloys in terms of their melting behavior and of the possible effects of Pb-contamination on manufacturing and reliability. The CALPHAD method of phase equilibria calculation using thermodynamic descriptions from databases provides a powerful tool for obtaining such information. The reliability of the calculation, however, depends on the quality of the thermodynamic descriptions of the individual phases. Criteria for the evaluation of these descriptions and the available thermodynamic databases are discussed. The effect of Pb-contamination on four solder alloys is analyzed.
Delaminating Layered Oxide Composites with Wavy Interfaces
Authors: Chen I.-W. , Winn E. J. 
Published: February 2022

Abstract
Two-phase zirconia/porous alumina layered composites with a variety of microstructures and good damage tolerance have been fabricated. The flatness of the layer microstructure can be controlled by deformation processing in the green state when the constituent ceramic powders are suspended in a fluid medium. Mismatch in deformation resistance leads to flow localization creating wavy layers without long-range coherence. Repeated folding and pressing further allows large deformation strains to accumulate and thin layers to be obtained. Under flexural loading, very high nominal strains can be sustained by successive layer fracture and delamination at the alumina-to-zirconia interface. Compared to conventional flat-layer laminates, these composites are attractive in view of their relative processing ease and their good mechanical performance.
Contemporary Materials Issues for Advanced EB-PVD Thermal Barrier Coating Systems
Authors: Leyens C. , Schulz U. , Fritscher K. , Bartsch M. , Peters M. , Kaysser W. A. 
Published: February 2022

AbstractThe key issues for thermal barrier coating (TBC) development are high temperature capability and durability under thermal cyclic conditions as experienced in the hot section of gas turbines. Due to the complexity of the system and the interaction of the constituents, performance improvements require a systems approach. However, there are issues closely related to the ceramic top coating and the bond coat, respectively. Reduced thermal conductivity, sintering, and stresses within the ceramic coating are addressed in the paper as well as factors affecting failure of the TBC by spallation. The latter is primarily governed by the formation and growth of the thermally grown oxide scale and therefore related to the bond coat. A strategy for lifetime assessment of TBCs is discussed.
Effect of Copper Line Geometry and Process Parameters on Interconnect Microstructure and Degradation Processes
Authors: Zschech Ehrenfried , Blum Werner , Zienert Inka , Besser Paul R. 
Published: February 2022

AbstractThe atomic transport processes which could cause degradation mechanisms in Cu interconnects are described. The influence of interconnect line width, barrier type and anneal process on the microstructure and reliability of the inlaid Cu lines are discussed. Grain size and texture measurements have been performed at blanket films and at arrays of Cu lines using advanced analytical techniques. The median grain size decreases with decreasing line width, and it can be influenced by heat treatments. The crystallographic texture is predominantly {111} out-of-plane with sidewall-oriented grains in narrow Cu lines. The grains have an in-plane preferred orientation with the 〈110〉 direction parallel to the sidewall normal. The Cu texture is influenced by barrier structure and thickness.
Prediction of Local Strain and Hardness in Sheet Forming
Authors: Thomas Sven , Müller Clemens , Exner Eckart 
Published: February 2022

Abstract
A simulation procedure to predict local deformation and properties in deep drawing and other sheet forming processes has been developed, and model experiments were performed to verify the predicted local strain after various ways and degrees of deformation. A strip of aluminium alloy sheet was pulled through a gap between a die and a punch, and bent around a rounded edge and bent back again. Local strains in a cross section of the sheet were estimated from hardness values measured before and after bending by using the hardness – strain relationship obtained for the alloy from tests carried out in tension and compression and with alternating deformation. The finite element (FE) model using ABAQUS was adjusted to the experimental set-up as closely as possible. The agreement between predictions and experiments is in the range of experimental scatter and the general trends are excellently reproduced. However, the precision of hardness measurements is not high enough to check the reliability of the numerical predictions in detail.
Interplay between chemical and magnetic roughness of Pt in a Pt/Co bilayer investigated with X-ray resonant magnetic reflectometry
Authors: Geissler J. , Goering E. , Weigand F. , Schütz G. 
Published: February 2022

Abstract
The magnetization depth profiles of Pt have been investigated by X-ray resonant magnetic reflectivity measurements of sputtered Pt/Co bilayer systems with different chemical roughness values at the Pt/Co interface. The asymmetry ratio as a function of the angle of incidence has been measured at the Pt L3 near-edge absorption region at the maximum of the X-ray magnetic circular dichroism effect. The observed asymmetry ratios in the order of 0.5% are described quantitatively on the basis of a magnetically modified optical approach. The curves of the extracted magnetization profiles in the Pt layer show a different behavior corresponding to chemical roughness, while the magnetic saturation moment of Pt at the Pt/Co interface remains unaltered.
Thermal stability and magnetic anisotropy dispersion in high-density hard-disk media
Authors: Papusoi Cristian , Suzuki Takao 
Published: February 2022

Abstract
A method to correct the anisotropy field distribution for granular recording media, measured by switching methods (isothermal remanent magnetization (IRM) and direct-current demagnetisation (DCD) processes were used as an example) for the effects of thermal relaxation, that supposes an a priori knowledge of the grain size distribution, is presented. For a hard-disk medium, it is shown that the anisotropy field distribution is much narrower (about one order of magnitude) with respect to the grain size distribution. The anisotropy field value estimated from the dependence of the remanence coercivity on the field application time is found in agreement (to within less than 10 %) with the most probable value of the anisotropy field distribution.
Magnetic relaxation in nanocrystalline systems: linking Monte Carlo steps with time
Authors: Vargas P. , Knobel M. , Altbir D. 
Published: February 2022

Abstract
The magnetic relaxation of a noninteracting two-dimensional ensemble of magnetic nanoparticles is simulated as a function of temperature using a Monte Carlo technique. By properly fitting the decay of magnetization using real parameters it is possible to make, at any finite temperature, a clear correspondence between Monte Carlo steps and time measured in seconds. The results allow one to visualize the intrinsic problems related to the simulation of nonequilibrium systems, and to understand the limits and range of validity of a particular system.
Effect of domain size on the magneto-elastic damping in amorphous ferromagnetic metals
Authors: Herzer Giselher 
Published: February 2022

Abstract
We show that the damping of longitudinal mechanical oscillations in soft magnetic amorphous ribbons can be significantly reduced by domain refinement. The latter is realized by an out-of-plane anisotropy induced by magnetic field annealing. The phenomena is interpreted in terms of micro eddy currents associated with the magnetization process within a domain.
Magnetic relaxation phenomena in cobalt
Authors: Blythe H.J. 
Published: February 2022

Abstract
The magnetic relaxation spectrum of polycrystalline, unirradiated Co has been investigated from 4 to 700 K. Both polycrystalline and single-crystal hexagonal close-packed Co have also been investigated after 3 MeV electron irradiation at either 8 or 40 K to doses of 1023 m–2. For unirradiated Co, results are interpreted as due to interactions between dislocations and domain walls. After irradiation at 8 K, relaxation peaks occur in the range 10 –50 K due to the re-orientation of Frenkel pairs which stabilise at the start of the stage-I anneal; a relaxation at 75 K is attributed to an intrinsic interstitial trapped at interstitial carbon. On anneal in the range 220 – 400 K, low-temperature relaxations evolve in samples containing impurities; these are attributed to reorientation of the migrating stage-III defects trapped at impurities.
Effect of rare-earth metals on the hot strength of HSLA steels
Authors: Cabrera José María , Mejía Ignacio , Prado José Manuel 
Published: February 2022

Abstract
An experimental study was done on the effect of rare-earth metals on a high-strength low-alloy steel. The work was focused in deriving the influence on Ce and La on the hot-working behavior. For this purpose, uniaxial hot-compression tests were carried out in a wide range of temperatures and strain rates. The effect of the rare-earth metals was determined by comparison of the characteristic parameters, describing the constitutive equations of the high-temperature response of the steel with, and without, rare-earth metals. The results showed that rare-earth metals were playing a major significant role on hardening mechanisms rather than on softening by dynamic recovery. On the contrary, rare-earth metals were able to delay the onset of dynamic recrystallization. All the present experimental results suggested that the latter roles are played by solid solution strengthening, through a solute drag effect, and not by precipitated particles.
Wear behaviour of Ni–Cr–Mo–V steel under dry sliding
Authors: Pathak J. P. , Mohan S. 
Published: February 2022

Abstract
Dry-sliding wear behaviour of bainitic structure (BS) and tempered martensitic structure (TMS) of Ni–Cr–Mo–V steels have been investigated at room temperature, using a pin-on-disc wear testing rig. These two microstructures reveal the rising trend of wear rate with normal applied load and sliding velocities in the initial stages; but once a maxima is attained in wear rate, then wear rate decreases with further increase in applied load or sliding velocity. It is also observed that wear resistance of TMS steel is superior to BS steel, but the difference in wear rate is not significant. The stereo-micrographs of debris generated show the oxidative and metallic modes of wear for both the microstructures. The study of worn surface clearly highlights the oxide formation, smearing of surface and distortion associated with straining and plastic deformation. The micro-ploughing, spalling and subsequent detachment of oxides and metallic surface layers from the worn-out surface of the pin specimen are the dominant mechanisms of the wear under different conditions of applied loads and sliding velocities. The wear rate is very much influenced by the yield strength and hardness of the bainitic and tempered martensitic steels.
Peritectic equilibrium in Fe-Co alloys
Authors: Sumida Masaki , Kurz Wilfried 
Published: February 2022

Abstract
Recent results of directional solidification experiments with Fe–Co alloys were not consistent with the presently accepted peritectic phase diagram. Therefore, the Fe-rich part of this phase diagram was re-examined. High-temperature gradient plane front solidification was carried out at a low velocity. After quenching of the specimen from the peritectic temperature, the compositions of the phases close to the solid/liquid interface were determined through electron probe microanalysis. Using these results together with previously published phase diagram information, an improved phase diagram is proposed with the peritectic equilibrium at T
p = 1774 K, C
δ = 17.7, C
γ = 18.1 and C
L = 19.5 at.% Co.
Artificial silicide barrier coatings in titanium matrix composites
Authors: Dudek H. J. , Weber K. 
Published: February 2022

Abstract
A continuous S2 silicide ([Ti,Zr]
x
Si
y
) segregation layer was found in the fibre matrix interface of SCS6-SiC/Ti-5.8Al-4Sn-3.5Zr-0.7Nb-0.5Mo-0.35Si (IMI834) composites (composition in wt.%). The S2 layer separates completely the titanium matrix from the reaction layer. It was shown that the S2 layer stabilises the interface during thermal treatment. The thermal stability of composites was tested in which artificial coatings were introduced into the interface. For the artificial coatings a composition and structure of the S2 silicides were aspired. The interface of the composites was investigated with analytical transmission electron microscope in the as-processed condition and annealed at 700 °C for 3 000 h and at 800 °C for 1000 h. The coatings of the same composition and structure can be introduced into the interface of SiC-SCS6/IMI834 composites as those of the S2 silicide obtained by self-segregation. The composites with the artificial coatings have a similar interface stability at 700 °C as those obtained by self-segregation.
Ordering processes and atomic defects in FeCo
Authors: Seeger Alfred 
Published: February 2022

Abstract
The present knowledge on self-diffusion and lattice vacancies in near-stoichiometric body-centred cubic FeCo alloys is critically reviewed and related to the establishment of structural order in the alloy after quenching from elevated temperatures. The available data may be consistently explained in terms of the so-called six-jump cycle mechanism of Huntington, Elcock and McCormick, plus the additional concept of ‘pseudo-selfdiffusivity’. It is shown that this leads to an understanding of the observed combinations of high activation enthalpy and large pre-exponential factor in the Fe self-diffusivity on the one hand, and of a lower activation enthalpy and ‘normal’ pre-exponential factor in the Co self-diffusion on the other hand. For some vacancy properties numerical estimates are given. The potential of muon spin rotation measurements for filling existing gaps in our knowledge is emphasized.
A critical discussion of the “500 °C anomaly” shows that the explanations attempted in the literature are unsatisfactory. It is proposed that the tetragonality of the compounds FeCo3 and Fe3Co predicted by ab-initio calculations of Díaz-Ortiz et al. may lead to a metastable pattern of antiphase domains on a very small scale, the dissolution of which may cause the anomaly.
Electron tomography of microelectronic device interconnects
Authors: Yang Qing , Mardinly John , Kübel Christian , Nelson Chris , Kisielowski Christian 
Published: February 2022

Abstract
As the dimensions of microelectronic devices continue to decrease, single transmission electron microscopy images are not able to properly represent the 3D structures when the structure’s curvature is comparable to the sample thickness. Electron tomography was used to study cylindrical vias coated with Ta-barrier layers and Cu-seed layers in 3D. Tomography reconstructions from both bright field images and high angle annular dark field images are presented. Fidelity of the reconstruction from single-axis and dual-axis tilt series is compared. Strategies for improving the fidelity of the reconstruction and making electron tomography practically applicable for device failure analysis of microelectronic industry are discussed.