Specialist Subjects:

Thermo-mechanical fatigue
Creep lifing
Titanium alloys
Nickel Alloys
Crystallographic texture
Fatigue Lifing
Fatigue/Creep/Environment Interactions

Publications

  1. & Microstructural characterisation of a nickel alloy processed via blown powder direct laser deposition (DLD). Materials & Design 117, 47-57.
  2. & Creep Deformation by Dislocation Movement in Waspaloy. Materials 10(1), 61
  3. & The influence of phase angle, strain range and peak cycle temperature on the TMF crack initiation behaviour and damage mechanisms of the nickel-based superalloy, RR1000. International Journal of Fatigue
  4. & The changing constants of creep: A letter on region splitting in creep lifing. Materials Science and Engineering: A 632, 96-102.
  5. & Thermo-Mechanical Fatigue Crack Growth of RR1000. Materials 10(1), 34

See more...

Teaching

  • EG-283 Mechanical Deformation in Structural Materials

    Following on from the first year module "Mechanical Properties" this module provides further detail about the deformation characteristics of a wide range of engineering materials. The course aims to develop the understanding of topics taught in the first year module by application to high performance materials such as titanium and nickel. Further understanding of deformation and damage mechanisms is gained through targeted units on elasticity, plasticity, alloy strengthening, fatigue and creep. The knowledge provided then allows for topics such as methods of mechanical testing and additive layer manufacturing. The module then seeks to draw these topics together by considering application to three main material classes, metals, ceramics and composites

  • EG-397 Propulsion

    The course aims to provide a basic understanding of propulsion systems in order to contribute to graduating students obtaining a holistic understanding of the aerospace sector. The course includes:- - Propulsion unit requirements for subsonic and supersonic flight - Piston engine components and operation - Propeller theory - Gas turbine engines: operation, components and cycle analysis - Thermodynamics of high speed gas flow - Efficiency of components - Rocket motors: operation, components and design - Dynamics of rocket flight - Environmental issues

  • EGA306 Mechanical Deformation in Structural Materials

    The course aims to develop the understanding of basic material properties by application to high performance materials such as titanium and nickel which are relevant to the medical engineering field. Understanding of deformation and damage mechanisms is gained through targeted units on elasticity, plasticity, alloy strengthening, fatigue and creep. The knowledge provided then allows for topics such as methods of mechanical testing and additive layer manufacturing. The module then seeks to draw these topics together by considering application to three main material classes, metals, ceramics and composites

  • EGTM04 Project Planning

    Each candidate will prepare a detailed project plan covering background to the research, the scheduling of practical and other work, and milestone deliverables. This plan will be produced following: (i) attendance at specialist lectures covering issues of good practice in the conduct of research eg safety, procedures for laboratory work and data reporting/analysis; (ii) discussion with academic and industrial supervisors regarding technical/commercial issues associated with the specific topic; (iii) a review of the formal course units covering technical issues, personal and professional development and research skills. The overall report must demonstrate that each student relates relevant aspects of the training courses to their industry oriented research project. Not available to visiting or exchange students.

  • EGTM64 Design Against Creep Failure

    The module defines low and high temperature creep in metallic and ceramic based materials. Deformation mechanisms and bulk measurements are described as a basis for predictions of mechanical component behaviour.

  • EGTM75 Financial Investment in Engineering

    This module, a combination of interactive seminars and computer based exercises, will provide engineering students with a detailed appreciation of financial investment for the technical environment. It will highlight the role of the individual and management during financial decision making procedures and associated risk assessment. Case studies of large scale investments in the aerospace industry will be employed throughout the course.

  • EGTM93 Holistic Gas Turbines and Materials Selection

    The module aims to give a complete understanding of the main aspects of gas turbine design. It is ¿holistic¿ in its emphasis on the links between performance aerodynamics, mechanics and the associated materials selection. These design criteria will be applied to the case study of a simple turbofan or intercooled/recuperated marine/industrial engine, using only hand calculations on paper (i.e. without the aid of a computer) and working in small teams.

  • EGXM22 Probability & Statistics

    This module introduces the concepts and practice of probability and statistics. Topics include: descriptive statistics, exploratory data analysis, the concept of uncertainty, probability theory, discrete and continuous probability models, inferential statistics, point and interval estimation, tests of statistical hypotheses, confidence intervals, correlation and regression.

  • EGXM23 Advanced Neutron and Synchrotron Methods

    A series of masterclasses run over five days of 2-3 hours each followed by interactive sessions or examples classes in the afternoon.

  • EGXM24 Crystal Defects

    This course aims to give an understanding of the role of crystal defects (dislocations, stacking faults and cracks) on in determining the plasticity and toughness of ultra-high temperature materials and alloys over a wide range of temperature. The approach is to understand the underlying principles involved and to demonstrate these with exercises and specific examples.

  • EGXM25 Nickel Based Superalloys

    This course aims to give a broad knowledge of the physical metallurgy of Nickel-based superalloys, their uses virtues and limitations. Emphasis will be put on understanding the general principles of the alloying strategies used in the various families of alloys and rationalising the physics and chemistry of the resulting compositions to the properties obtained. Teaching will be by interactive lectures and supervised exercises in the afternoons including the use of Thermocalc to investigate phase equilibria. This will include an exercise to design a superalloy.

  • EGXM26 Nanostructured Steels

    A wide range of nanostructures is available for ferrous alloys. When the surface to volume ratio of the nanostructure increases, interesting interactions between defects in the crystal structure such as dislocations, vacancies and interstitial atoms occur. These allow for the combination of extraordinary properties, such as tensile strength and ductility exceeding 2.5 GPa and 10%. However, phase stability and low cost heat treatments become a challenge, especially for high temperature applications. Strong emphasis is placed on developing computational skills aiding in conceiving the new emerging families of nanostructured steels.

Supervision

  • MA by DLD - Mechanical property evaluation (IN718) (current)

    Student name:
    EngD
    Other supervisor: Prof Martin Bache
  • Interactions of stress and oxidation in Ni-based alloys (current)

    Student name:
    EngD
    Other supervisor: Prof Martin Bache
  • An investigation into the thermal mechanical fatigue behaviour of TiMMCs (current)

    Student name:
    EngD
    Other supervisor: Prof David Worsley
  • Quantification of the microstructure and metallurgical properties of complex forging alloys (current)

    Student name:
    MSc
    Other supervisor: Dr Robert Lancaster
  • The thermal degradation of 300 series austenitic stainless steel welds (current)

    Student name:
    MSc
    Other supervisor: Dr David Penney
  • Quantification of the Microstruture and metallurgical properties of complex nickel forging alloys (current)

    Student name:
    MSc
    Other supervisor: Dr Robert Lancaster
  • Thermo-mechanical fatigue crack propagation behaviour in titanium alloys (current)

    Student name:
    EngD
    Other supervisor: Prof Geraint Williams
  • TBC (current)

    Student name:
    EngD
    Other supervisor: Dr Helen Davies
  • Using atom probe tomography and small angle neutron scattering to study preciptation in a novel marging steel (current)

    Student name:
    PhD
    Other supervisor: Prof Martin Bache
  • Untitled (current)

    Student name:
    EngD
    Other supervisor: Dr Robert Lancaster
  • Untitled (current)

    Student name:
    EngD
    Other supervisor: Dr David Penney
  • Untitled (current)

    Student name:
    PhD
    Other supervisor: Dr Helen Davies
  • The effect of salt composition and other species on the static and cyclic corrosion performance of a nickel based superalloy (current)

    Student name:
    EngD
    Other supervisor: Mr Michael Dowd
  • 'The constitutive behaviour of a nickel based superalloys' (awarded 2017)

    Student name:
    PhD
    Other supervisor: Prof David Worsley

Career History

Start Date End Date Position Held Location
2012 Present Senior Lecturer Materials Research Centre, Swansea University
2007 Present RCUK Fellow Materials Research Centre, Swansea University
2003 2007 Research Officer Materials Research Centre, Swansea University

Invited Presentations, Lectures and Conferences

Date Description
2004 “Texture, microstructure and mechanical properties in Ti6-4”, Ti 2003 Science & Technology 3, pp 1759-1766
2006 “Prediction of LCF initiation lives in DEN specimens based on strain control testing of plain Ti6246 specimens”
2006 “Prediction of notched specimen behaviour in textured Ti-6Al-4V”, 9th International Fatigue Congress, Atlanta
2007 “Torsion fatigue in near alpha and alpha titanium alloys”, 11th International titanium conference, Kyoto
2007 “Effect of prestrain on ambient and high temperature creep in Ti834”, 11th International titanium conference, Kyoto
2008 “Characterisation of stress concentration features in the +  titanium alloys” 11th Portuguese conference on fracture
2009 “Time Dependent Fracture of Titanium Alloys” 12th International Conference on Fracture, Ottawa, Ontario, Canada
2009 “Fracture mechanisms due to Fatigue, Creep and Environmental damage in titanium alloys” 12th International Conf. on Fracture
2009 “Creep fracture of centrifugally-cast HK40 tube steel”, ECCC creep conference, Zurich
2011 “Fatigue life variation due to microstructure in Ti6-4” 12th World conference on Titanium, Beijing
2012 “The Wilshire Equations for Long-Term Creep Life Prediction”, Creep 2012
2012 “High Temperature Creep Behaviour of Gamma Titanium Aluminides (-TiAl)” Creep 2012

External Responsibilities

  • Board Member, Institute of Materials Structure and Properties of Materials

    2011 - Present

  • External Examiner at PhD and MRes Levels, The University of Birmingham

    2012 - Present

Awards And Prizes

Date Description
2007 Awarded Chartered Physicist Status
2007 Awarded RCUK Research Fellowship

Research

Thermo-mechanical fatigue

Within the gas turbine engine, the high transient thermal stresses resulting from throttle movement from idle to high settings give rise to the phenomenon of thermo-mechanical fatigue (TMF). These effects have been widely explored for turbine blade materials, typically single crystal nickel alloys. More recently however, a combination of thinner disc rims and further increases in turbine entry temperature has lead to a situation where TMF in disc materials cannot be ignored. Turbine discs will usually be manufactured from polycrystalline nickel alloys, and as such it is now considered critical that TMF effects in this system of alloys is fully characterised. Research within the Institute of Structural Materials in collaboration with Roll-Royce plc leads the way in the development of modelling approaches to TMF through a range of cutting edge experimental techniques.

Modern creep lifing approaches

Traditional creep lifing techniques based on power law equations have shown themselves to be extremely limited, particularly in the prediction of long term data based only on short term experimental data. More recently, alternative approaches such as the Wilshire equations and hyperbolic tangent methods have been proposed which offer a new insight into the field. Ongoing research within the Institute of Structural Materials focuses on the development of the Wilshire equations in particular, their relationship with microscopic behaviour of engineering alloys and their application to a range of materials that currently includes copper, aluminium alloys, steels, titanium alloys, nickel superalloys and titanium aluminides.

Titanium alloys

Premature failure of titanium based engineering components in the 1970s brought to attention the phenomenon of dwell effects at low temperatures in these alloys, loosely termed ‘cold creep’, which are currently still a major concern for designers. Ongoing research at the Institute of Structural Materials seeks to address the issue through targeted mechanical testing and microscopic evaluation. The presence, extent and effect on mechanical properties of cold dwell related features such as ‘quasi-cleavage’ facets are investigated with the resultant effect on both creep and fatigue life also studied.

Measures of Esteem

  • Invited contribution to book (single author) – Gas Turbines (ISBN 978-953-307-324-8.) – Chapter title – Titanium in the Gas Turbine engine.
  • Invited speaker – Power plant cycling conference, North Carolina, 2012
  • Co-author of invited papers (Fatigue 2007, Grain Boundaries at High Temperatures 2009)
  • Act as an international consultant on titanium alloys and creep lifing
  • Reviewer for 5 major international journals - International Journal of Fatigue, Journal of Materials Science, Metallurgical & Materials Transactions A, Fatigue & Fracture of Engineering Materials & Structures