(2021). Alan Lidiard Obituary. Philosophical Magazine: Vol. 101, No. 8, pp. 905-906.

ABSTRACT An in-depth understanding of the role of non-metallic inclusions (NMIs) in the hydrogen-induced failure of structural materials is important in the manufacture and application of steels. In this paper we investigated the type, the amount and the distribution of NMIs in pipeline steels and their relation to the susceptibility to hydrogen-induced cracking (HIC). Scanning Electron Microscope

ABSTRACT A number of recent Molecular Dynamics (MD) simulations have demonstrated that screw dislocations in face centred cubic (fcc) metals can achieve stable steady state motion above the lowest shear wave speed ( vshear) which is parallel to their direction of motion (often referred to as transonic motion). This is in direct contrast to classical continuum analyses which predict a divergence in

ABSTRACT Confined geometries offer useful and experimentally amenable mechanical testing arrangements in which to study the molecular and micro-structural processes which govern plastic yield in stress environments dominated by hydrostatic pressure over shear. However, the changes to macroscopic stress – strain behaviour that result from switching from an unconfined mode such as uniaxial compression

ABSTRACT The present work has examined the influence of strain path change on the deformation behaviour, texture evolution and recrystallisation process in an extruded pure magnesium. The samples were compressed at room temperature along ED, ND and ND–ED directions to the same total strain. Electron back-scattered diffraction (EBSD), hardness testing and X-ray diffraction were utilised to examine the

ABSTRACT Pop-in is a widely observed phenomenon in nanoindentation. In this paper, dislocation evolution in pop-in processes is analysed in detail through molecular dynamics (MD) simulations. We found that a large number of dislocations nucleate homogeneously at the initiation of pop-in, followed by extensive dislocation propagation, which is the dominant mode of plastic deformation during pop-in.

ABSTRACT Natural pyrrhotites have gained significant attention due to their interesting electronic, antimicrobial, and chemical properties. The present work attempts to explore the morphology-induced modifications in the thermal characteristics of natural pyrrhotite due to ageing. The morphological, elemental, structure, optical, and thermal characterisations help in understanding the effect of ageing

ABSTRACT We employ molecular dynamics simulations to investigate the evolution dynamics of {101¯2} twinning in single-crystal Ti under shock loading. The shock compression applied perpendicular to the c-axis leads to the activation of {101¯2} twins in single-crystal Ti. We find the twin variant activation for each case of the applied loading conditions follows Schmid criterion. However, the time for

ABSTRACT Similarity has been proven between the Lifshitz topological transitions (LTT) in AB-stacked trigonally warped bilayer graphene (TWBG) and graphite near K points. The density of states (DOS) has been shown to have the van Hove singularities (VHS) of type (ϵc−|ϵ|)−1/2 at LTT in AB-stacked (TWBG) and graphite near K points. The topology evolutions of the iso-energetic lines at LTT have been established

ABSTRACT The spin-polarized full-potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory (DFT) and the exchange and correlation potential is treated with the generalized gradient approximation (GGA) and the Coulomb repulsion (GGA + U), as well as the modified Becke-Johnson approach (GGA-mBJ) are investigated on the structural, elastic, electronic and magnetic

ABSTRACT Indentation scaling relationships intend to guide indentation experiments and help understand the indentation hardness. In the present study, dimensionless functions were obtained by fitting a series of numerical results of the cross-scale indentation tests based on a strain gradient plasticity theory. The closed-form indentation scaling relationships were found between dimensionless material

ABSTRACT The micromechanism-based stepwise strain hardening behaviour of copper single crystals significantly depends on the competition and collaboration between dislocation slip and deformation twinning. A crystal plasticity-based model of the strain hardening characteristics associated with slip and twinning interactions is proposed that focuses on modelling the stepwise strain hardening behaviour

ABSTRACT Weakly interacting Fermi liquid can exhibit integer or fractional quantum Hall effect at sufficiently low temperatures, and in the presence of variable applied magnetic and/or electric fields. The said effects have been captured only incompletely by means of the Klitzing conductance formula, e2/h multiplied by the dimensionless filling factor (integer or fractional), ν because scattering rate

ABSTRACT A finite element microstructure model with permeability tensors that considers crystallographic texture and grain size based on magnetic domain theory has been developed for the evaluation of magnetic anisotropy in polycrystalline steels. The model has proved capable of capturing the crystallographic texture, the grain size and the vector induction effects on the effective permeability behaviours

ABSTRACT Although the compressive strength of ice under both quasi-static [M. Arakawa and N. Maeno, Mechanical strength of polycrystalline ice under uniaxial compression. Cold Reg. Sci. Tech 26 (1997), pp. 215–229.] and dynamic [X. Wu and V. Prakash, Dynamic compressive behavior of ice at cryogenic temperatures. Cold Reg. Sci. Tech 118 (2015), pp. 1–13.] loadings shows an anomalous temperature effect

ABSTRACT The precipitation of carbides at grain boundaries in nickel-based superalloys and austenitic stainless steels can significantly affect the grain boundary related properties of the bulk material. This study evaluated the growth and dissolution of carbides in grain boundary engineering (GBE) treated nickel-based superalloy (Inconel 690) during aging treatment using scanning electron microscopy

ABSTRACT In this paper, the influence of growth rates on the microstructure and magnetostrictive properties of Fe83Ga17 directional solidification alloys were investigated. The microstructure and magnetic properties of Fe83Ga17 as-cast and directional solidification samples were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), optical

ABSTRACT We employ molecular dynamics simulations to investigate the role of temperature on the evolution dynamics of the voids in single crystal iron. We simulate isotropic tension in single crystal iron at a constant strain rate with temperature in the range of 300–1200 K. We find that the number of voids is highest at 1200 K in comparison to that at 300 K indicating high nucleation events at high

ABSTRACT Non-uniform height semiconductor quantum rings are studied in order to determine their electronic and optical absorption properties. Theoretical modelling of the structure includes an analytical description of the non-regular multi-hilled confining potential as well as the presence of repulsive scattering centre and external crossing electric and magnetic fields. We have discussed the features

ABSTRACT In this report, SrFeO3-δ nanoparticle perovskite sample was prepared by the co-precipitation method. Rietveld refinement of the X-ray diffraction (XRD) data of SrFeO3-δ sample showed that it has a cubic phase (space group: Pm3 m). The morphology and average size (11.15 nm) of the SrFeO3-δ nanoparticle samples were characterised by the high-resolution transmission electron microscope (HRTEM)

ABSTRACT We discuss surface roughness effects on the conduction of electrons in metals using both the quantal Kubo–Greenwood formalism and the semi-classical Fuchs–Sondheimer method. The main purpose here is to compare these methods and clarify a few subtle and widely misunderstood conceptual issues. One of such issues is concerned with the conditions under which the broken translation symmetry along

ABSTRACT The temperature, hydrostatic pressure, and external electric field effects on the confined exciton in cylindrical quantum dots by considering a parabolic confining potential are investigated. The effects of these external perturbations on the binding energy and interband emission energy are calculated numerically by adopting the variational method within the effective mass approximation. Our

ABSTRACT It is well known that cracks are observed on the surface without load when pure nickel is left in ambient air after hydrogen charge. It has been due to the decomposition of nickel hydride generated during hydrogen charging. In the present work, microcracks were investigated at the surface and inside the specimen with suppressing the decomposition of nickel hydride in polycrystalline pure nickel

ABSTRACT Atom probe tomography (APT) and selected area electron diffraction (SAED) by transmission electron microscopy (TEM) were applied to nano-scale precipitates formed in a neutron-irradiated iron (99.99% pure) at high temperatures. In the conventional TEM, we discovered donut-type precipitates on the {100} planes that formed at the dilatational side of interstitial type dislocation loops with

ABSTRACT The shear of a crystalline interface by a matrix dislocation is an elementary phenomenon of plasticity that generates a three-dimensional elastic field difficult to express. However, in the case of a flat interface and two elastic isotropic media, the present work shows that this field can be described starting from an explicit form of the Green tensor associated with a point force exerted

ABSTRACT A duplex treatment, namely, plasma carbonitriding followed by multi-arc ion plating, was used to improve the high-temperature tribological properties of TiAlCrN coatings on 300M steel in this research. The carbonitriding layer was first prepared on 300M steel substrates by the double glow plasma metallization technique. A corresponding heat treatment was performed, and then the TiAlCrN coating

ABSTRACT A novel 3d transition metal high entropy alloy (3d TM HEA), Al0.5CoCuNiTi, was prepared by arc-melting. The phase component, microstructure, and mechanical properties in as-cast and annealed conditions were investigated. The results showed the phase structures of the studied alloys in both states were composed of FCC and BCC. The BCC phase was the absolute primary phase with a volume fraction

ABSTRACT In this study, cracks propagating in WC grains are investigated at the atom scale along the [0001] axis. A brittle crack, characterised by cleavage along {1, 0, −1, 0} prismatic facets and the absence of dislocations is observed. The crack follows a zig-zag path allowing a higher deformation energy to be absorbed by the crystal. A ductile crack is also characterised. The plastic zone is limited

ABSTRACT We present Surface Evolver computer simulations for two-dimensional (2d) foams in which the contact angle at which liquid films and Plateau borders meet is non-zero. We determine the average coordination number Z of bubbles over a wide range of finite contact angles θ and liquid fractions ϕ. We find a linear scaling of Z for values of ϕ between about 0.07 and 0.15, corroborating previous data

ABSTRACT Good interface bonding is the basic prerequisite to achieve a high thermal conductivity of the composites. Clarifying the binding mechanism of Al/Mo2C interface is of great significance for the scheme design of Al/Diamond interface regulated by Mo element. The atomic structure and electronic properties of Al(111)/Mo2C(0001) interfaces and the influence of Mo doping on its adhesion work were

ABSTRACT In the literature, the volume of a cluster (i.e. a fluctuation of the solid solution or a precipitate) is identified as the volume of a sample of the bulk precipitate phase containing the same number of solute atoms (i.e. of the same size). This approximation is suitable for macroscopic precipitates but is debatable for a rigorous description of microscopic clusters, especially during the

ABSTRACT An understanding of nucleation, growth and coalescence of voids is required to predict the spall fracture. We employ molecular dynamics simulations to investigate the effect of temperature on the nucleation and growth of voids in single crystal copper under triaxial loading condition. We find that the void density decreases with an increase in temperature. The nucleation rate of the voids

ABSTRACT The occurrence of the anomalous behaviour of increased isothermal solidification completion time, t f with increasing temperature in transient liquid phase (TLP) bonding, is investigated for cases of one-dimensional and multi-dimensional migration of solid–liquid boundary, using a numerical model. The analysis shows that the anomalous behaviour is not restricted to the generally reported one-dimensional

ABSTRACT A number of recent Molecular Dynamics (MD) simulations have demonstrated that screw dislocations in face centred cubic (fcc) metals can achieve stable steady state motion above the lowest shear wave speed ( v s h e a r ) which is parallel to their direction of motion (often referred to as transonic motion). This is in direct contrast to classical continuum analyses which predict a divergence

ABSTRACT Using first principle calculations based on the density functional theory (DFT), the structural, elastic, electronic, and thermoelectric properties, and thermodynamic stability of the LiMgZ (Z = P, As, Bi) half-Heusler ternary compounds were studied. The results of structural calculations and elastic constants and investigation of the thermodynamic phase diagram represent stability for these

ABSTRACT By adding alloying elements in Pt, the solid-solution strengthening is extensively used to improve the mechanical properties of Pt-based alloys, one of the most promising high-temperature materials due to its higher melting point. Yet the microscopic mechanism of the alloying effects on the mechanical properties of Pt is unclear. Based on a systematic study of the influence of alloying elements

ABSTRACT We investigate the magnetisation and internal energy of the David star in the Kagome lattice by the effective field theory developed by Kaneyoshi. First-order, Second-order and successive phase transitions are observed for different spin-down orientations. Spin-down orientation of identical atoms causes a second-order phase transition, spin-down orientation of different atoms causes a first-order

ABSTRACT The MnNiFeGe alloy is prepared by high-pressure annealing method. It is found that the martensitic transformation temperature after high-pressure annealing of this alloy decreases with the increasing thermal hysteresis. Besides, another magnetic phase transition above the martensitic transformation is observed, which is due to the existence of a large amount of retained austenite induced by

ABSTRACT Understanding the evolution of dislocations and twinning at the crack front is critical for designing micro-mechanical systems with improved performance. In this work, the dislocation evolution at the crack front in thin pre-cracked FCC single crystals is correlated with the associated fracture toughness, which is shown to be dependent on material specific properties such as stable stacking

ABSTRACT High-temperature oxidation behaviour of an alumina-forming austenitic (AFA, Febalance–20Ni–14Cr–2.5Al–0.15Si–2Mn–2.5Mo–0.9Nb, in wt%) steel and W-substituted AFA steel was examined. The isothermal oxidation tests were performed on the two steels at 780°C for 2 weeks in air, which indicated that the substitution of W for Mo was beneficial to improve the oxidation resistance of the AFA steel

ABSTRACT We investigate the effects of a time-dependent gate voltage on a spin–orbit interaction (SOI) coupled interacting double quantum dot (DQD) system. For a tunnel coupled detuned DQD with two interacting electrons, SOI couples triplet T 0 and hybridised singlet state (1,1)–(0,2) through spin nonconserving transition. In order to explore the effects of Ac gate voltage on charge localisation, we

ABSTRACT We investigate the effects of a time-dependent gate voltage on a spin–orbit interaction (SOI) coupled interacting double quantum dot (DQD) system. For a tunnel coupled detuned DQD with two interacting electrons, SOI couples triplet T0 and hybridised singlet state (1,1)–(0,2) through spin nonconserving transition. In order to explore the effects of Ac gate voltage on charge localisation, we

ABSTRACT The present study deals with the properties of boronized and non-boronized low-alloy steel (34CrAlMo5-10). Specimens are characterised using microscopy, various spectroscopic techniques, nanoindentation, surface profilometer, and tribometer. The boronized region contains (i) (Fe, M)2B columns and (ii) matrix between the columns. Nanoindentation study reveals the difference in the mechanical

ABSTRACT As a class of typical topological structures, polarisation vortexes were characterised by the intensity vector which is defined as the curl of the polarisation at their cores. Some phase field simulations were conducted on the lead titanate nanofilms to evaluate the effects of model size, temperature, traction, and curled electric field on the formation and evolution of polarisation vortex

ABSTRACT As a class of typical topological structures, polarisation vortexes were characterised by the intensity vector which is defined as the curl of the polarisation at their cores. Some phase field simulations were conducted on the lead titanate nanofilms to evaluate the effects of model size, temperature, traction, and curled electric field on the formation and evolution of polarisation vortex

ABSTRACT The energies of small-angle tilt grain-boundaries have been predicted using the Read–Shockley model based on dislocation theory. However, experimentally observed energies have been inconsistent with the Burgers vector-dependent values derived from this theory. Finite-temperature predictions of grain-boundary energies, performed via first-principles calculations, show consistency with the experimental

ABSTRACT The energies of small-angle tilt grain-boundaries have been predicted using the Read–Shockley model based on dislocation theory. However, experimentally observed energies have been inconsistent with the Burgers vector-dependent values derived from this theory. Finite-temperature predictions of grain-boundary energies, performed via first-principles calculations, show consistency with the experimental

ABSTRACT The plates of an Fe–12%Mn–0.5%C–1.5%Al austenitic steel with an original grain size of 80 µm were subjected to friction stir welding using a spherical welding pin. The fine grained microstructures with a grain size being dependent on the welding feed speed were evolved in the stir zones. The microstructure evolution in the stir zone resulted from a kind of post-dynamic recrystallisation. An

ABSTRACT Adopting a unique electrical circuit design, here we treat a significant low-cost engineering material (eutectoid steel not containing costly alloying elements) with a high-voltage (100 kV) low-current (150 mA) energy input (energy level exceeding cohesive energy). A distinctive structural evolution is ascertained with treatment duration of only 5 min as an outcome of lamellar fragmentation

ABSTRACT The dynamical evolution of smectic-C liquid crystals in the presence of a magnetic field is studied. The theoretical analysis is based on dynamic renormalisation group techniques. The starting point of the analysis is the nonlinear elastic model of smectic-C liquid crystals followed by Langevin formulation. The dynamical model predicts the onset of Kosterlitz-Thouless transition at low frequency

ABSTRACT The lack of interstitial oxygen for locking and pinning of dislocations has made the ultra-high resistivity silicon wafers for radio frequency applications prone to slip and warpage during electronic device manufacturing. In this work, we investigate the role of germanium doping on the dislocation mobility in very low oxygen concentration, Czochralski-grown silicon wafers. Mechanical bending

ABSTRACT The aim of this article is to provide the displacement field of a straight dislocation in gradient elasticity that can be implemented in dislocation dynamics simulations. The displacement and plastic strain fields of a dislocation depend on the history of the dislocation motion. The cut surface (or the branch cut) represents this history. When an edge dislocation glides, the branch cut must

ABSTRACT Memory effects generated by a prolonged transverse electric field in the triglycine sulphate (TGS) ferroelectric were investigated quantitatively. Four characteristic temperatures were introduced, TS ≤ TA ≤ TH   < TC, where TC is a para-ferroelectric critical temperature. Measurements of depolarizing transverse electric current carried out in heating from TS (or TA) up to above TC were preceded

ABSTRACT Classical molecular dynamics simulations have been performed to investigate the microstructural evolution of single crystal titanium under equal channel angular extrusion process (ECAE). The ECAE loading condition has been simulated by constraining deformation along two directions and applying shear along one direction. We find that for the case where shear is applied along < 2 1 ¯ 1 ¯ 0 >

ABSTRACT The properties of the specific heat and elastic stiffness components at the charge density wave phase transition in several one-dimensional and two-dimensional materials are examined. Here we show that the thermodynamic properties of the rare earth tritelluride RTe3 ( R=Te, Er) and Lu 5Ir 4Si 10 compounds can be explained in the framework of a standard mean field Landau theory. The amplitude

ABSTRACT We use nanoindentation to perform elastic cycling on, and to characterise, the bulk metallic glass Cu46Zr46Al7Gd1. From multiple loading curves, cumulative distributions are determined for several properties, including the initial yield load, the hardness and the indentation modulus. The distributions are characterised by the median property value and by their width. The effects of elastic

ABSTRACT I comparatively determine the structural and electronic properties of Li2FePO4F compounds with F substituted by Cl, Br and I atom using the spin density functional theory with Perdew–Burke–Ernzerhof generalised gradient approximation (GGA + U). The lattice parameters and volumes are improved by the dopants because of the greater atomic radius in dopants. Non-metal doping in Li2FePO4F reduces

ABSTRACT Ni2MnSb Heusler alloy is modelled and its magnetic properties are investigated by means of the effective field theory (EFT) developed by Kaneyoshi. Furthermore, the structural and electronic properties are performed by using density functional theory (DFT). According to DFT, with the help of volume-energy optimisation curves, the ferromagnetic (FM) state is more stable in energetic than the

ABSTRACT The main raising propose in material science is to modify the structural, electronic, optical and magnetic properties. Here, the effect of substituted VIB transition metals in In2O3 semiconductor is analysed utilising the spin density functional theory with the generalised gradient approximation (GGA) by Perdew–Burke–Ernzerhof (PBE) formulation. W doping in In2O3 semiconductor is the most

ABSTRACT Electrochemical Impedance Spectroscopy and Raman studies are performed on fast ion conducting, AgI–Ag2O–MoO3 glasses, over a wide range of composition to understand the features of structure, ion migration and their correlation. These features essentially involve diffusion and relaxation. The coefficients associated with diffusion process, especially, the diffusion coefficient, diffusion length