Publications (22)
The interplay between thermomigration and stress-driven hydrogen transport in metals
Daniel J. Long, Edmund Tarleton, Alan C. F. Cocks +1
Thermomigration is the driving force for hydrogen transport due to a temperature gradient. It can compete with hydrogen transport induced by stress gradients. While stress-driven h…
The influence of hydrogen core force shielding on dislocation junctions in iron
Haiyang Yu, Ivaylo H. Katzarov, Anthony T. Paxton +2
The influence of hydrogen on dislocation junctions was analysed by incorporating a hydrogen dependent core force into nodal based discrete dislocation dynamics. Hydrogen reduces th…
Direct Imaging of Hydrogen-Driven Dislocation and Strain Field Evolution in a Stainless Steel Grain
David Yang, Mujan Seif, Guanze He +9
Hydrogen embrittlement (HE) poses a significant challenge to the durability of materials used in hydrogen production and utilization. Disentangling the competing nanoscale mechanis…
Orientation dependence of the nano-indentation behaviour of pure tungsten
Hongbing Yu, Suchandrima Das, Haiyang Yu +3
Coupling of nano-indentation and crystal plasticity finite element (CPFE) simulations is widely used to quantitatively probe the small-scale mechanical behaviour of materials. Earl…
Discrete dislocation plasticity HELPs understand hydrogen effects in bcc materials
Haiyang Yu, Alan Cocks, Edmund Tarleton
In an attempt to bridge the gap between atomistic and continuum plasticity simulations of hydrogen in iron, we present three dimensional discrete dislocation plasticity simulations…
Coherent X-ray measurements of ion-implantation-induced lattice strains in nano-crystals
Felix Hofmann, Edmund Tarleton, Ross J. Harder +6
Focussed Ion Beam (FIB) milling is a mainstay of nano-scale machining. By manipulating a tightly focussed beam of energetic ions, often gallium (Ga+), FIB can sculpt nanostructures…
Localised stress and strain distribution in sliding
Anna Kareer, Eralp Demir, Edmund Tarleton +1
In this paper, we present a comprehensive analysis of the contact mechanics associated with a micron-sized sliding asperity, which plays a crucial role in the abrasive wear process…
Macroscopic analysis of time dependent plasticity in Ti alloys
Yi Xiong, Phani S. Karamched, Chi-Toan Nguyen +4
Component failure due to cold dwell fatigue of titanium and its alloys is a long-standing problem which has significant safety and economic implications to the aviation industry. T…
Computation of Burgers Vectors from Elastic Strain and Lattice Rotation Data
Jacques Cloete, Edmund Tarleton, Felix Hofmann
A theoretical framework for computation of Burgers vectors from strain and lattice rotation data in materials with low dislocation density is presented, as well as implementation i…
Cold Creep of Titanium: Analysis of stress relaxation using synchrotron diffraction and crystal plasticity simulations
Yi Xiong, Phani Karamched, Chi-Toan Nguyen +4
There is a long standing technological problem in which a stress dwell during cyclic loading at room temperature in Ti causes a significant fatigue life reduction. It is thought th…
Characterisation of slip and twin activity using digital image correlation and crystal plasticity finite element simulation: Application to orthorhombic -uranium
Nicolò Grilli, Philip Earp, Alan C. F. Cocks +2
Calibrating and verifying crystal plasticity material models is a significant challenge, particularly for materials with a number of potential slip and twin systems. Here we use di…
Hardening and Strain Localisation in Helium-Ion-Implanted Tungsten
Suchandrima Das, Hongbing Yu, Edmund Tarleton +1
Tungsten is the main candidate material for plasma-facing armour components in future fusion reactors. In-service, fusion neutron irradiation creates lattice defects through collis…
Cold dwell behaviour of TiAl alloy: Understanding load shedding using digital image correlation and crystal plasticity simulations
Yi Xiong, Nicolo Grilli, Phani S. Karamched +3
Digital image correlation (DIC) and crystal plasticity simulation were utilised to study cold dwell behaviour in a coarse grain Ti-6Al alloy at 3 different temperatures up to 230 C…
Scratching the surface: Elastic rotations beneath nanoscratch and nanoindentation tests
Anna Kareer, Edmund Tarleton, Christopher Hardie +2
In this paper, we investigate the residual deformation field in the vicinity of nano-scratch tests using two orientations of a Berkovich tip on an (001) Cu single crystal. We compa…
Modified deformation behaviour of self-ion irradiated tungsten: A combined nano-indentation, HR-EBSD and crystal plasticity study
Suchandrima Das, Hongbing Yu, Kenichiro Mizohata +2
Predicting the dramatic changes in material properties caused by irradiation damage is key for the design of future nuclear fission and fusion reactors. Self-ion implantation is an…
A Thermodynamic Model for Thermomigration in Metals
Daniel J. Long, Edmund Tarleton, Alan C. F. Cocks +1
We investigate the mechanisms involved in the thermomigration of interstitial hydrogen in metals. Using irreversible thermodynamics, we develop a comprehensive mechanistic model to…
Dislocation density distribution at slip band-grain boundary intersections
Yi Guo, David M. Collins, Edmund Tarleton +3
We study the mechanisms of slip transfer at a grain boundary, in titanium, using Differential Aperture X-ray Laue Micro-diffraction (DAXM). This 3D characterization tool enables me…
Evaluation of local stress state due to grain-boundary sliding during creep within a crystal plasticity finite element multi-scale framework
Markian Petkov, Elsiddig Elmukashfi, Edmund Tarleton +1
Previous studies demonstrate that grain-boundary sliding could accelerate creep rate and give rise to large internal stresses that can lead to damage development, e.g. formation of…
Consistent determination of geometrically necessary dislocation density from simulations and experiments
Suchandrima Das, Felix Hofmann, Edmund Tarleton
The use of Nye's dislocation tensor for calculating the density of geometrically necessary dislocations (GND) is widely adopted in the study of plastically deformed materials. The…
The link between Microstructural Heterogeneity, Diffusivity, and Hydrogen Embrittlement
Daniel J Long, Edmund Tarleton, Alan CF Cocks +1
Green hydrogen is likely to play a major role in decarbonising the aviation industry. It is crucial to understand the effects of microstructure on hydrogen redistribution, which ma…
An in-situ synchrotron diffraction study of stress relaxation in titanium: Effect of temperature and oxygen on cold dwell fatigue
Yi Xiong, Phani S. Karamched, Chi-Toan Nguyen +5
There is a long-standing technological problem in which a stress dwell during cyclic loading at room temperature in Ti causes a significant fatigue life reduction. It is thought th…
Orientation-dependent indentation response of helium-implanted tungsten
Suchandrima Das, Hongbing Yu, Edmund Tarleton +1
A literature review of studies investigating the topography of nano-indents in ion-implanted materials reveals seemingly inconsistent observations, with report of both pile-up and…