Dr Helen Davies
Senior Lecturer
Engineering
Telephone: (01792) 602511
Room: Administration Office - 016
Ground Floor
Institute of Structural Materials
Bay Campus

Specialist Subjects:

Titanium alloys
Nickel Manufacture
Grain Boundary Engineering
Semi-solid forming
Additive Layer Manufacturing
Metals Casting
Failure Analysis (Metals)

Chartered Engineer (CEng) – Institute of Materials, Minerals and Mining.

MIMMM status – Full member of the Institute of Materials, Minerals and Mining.

Supervision

Postgraduate Taught Masters

Microstructural evaluation of joining/repair processes for aerospace applications

Postgraduate Research

  1. Validation of a high integrity joining/repair process for aerospace applications
  2. Thermo-mechanical characterisation of a nickel super alloy
  3. Alternative Joining Techniques for Ti alloys Powder Interlayer Bonding
  4. High Integrity Joining and Repair of Gamma TiAl (2nd Supervisor)
  5. Fatigue Behaviour of Novel Titanium Alloys (2nd Supervisor)

Areas of Expertise

  • Materials
  • Metals
  • Fatigue
  • Microstructure

Publications

  1. & Localized microstructural characterization of a dissimilar metal electron beam weld joint from an aerospace component. Materials & Design 90, 101-114.
  2. & Effects of hot isostatic pressing on the elastic modulus and tensile properties of 316L parts made by powder bed laser fusion. Materials Science and Engineering: A 693, 186-213.
  3. & Establishing a quantifiable tarnish timeline for comparison of anti-tarnish processes in metals. Materials and Corrosion 66(10), 1120-1124.
  4. & Optimizing gate location to reduce metal wastage: Co–Cr–W alloy filling simulation. Journal of Materials Processing Technology 240, 249-254.
  5. & Computational modeling of creep-based fatigue as a means of selecting lead-free solder alloys. Microelectronics Reliability 54(6-7), 1235-1242.

See more...

Teaching

  • EG-268 Experimental Studies - Mechanical

    The course introduces the students to experimental studies in a wide range of subjects. There are Four Individual experiments (HEAT/JET/STRESS/VIBRATION) Each experiment is self contained and the student will be assessed via either: - a lab report which will have a set of experiment specific questions to answer. - An online Blackboard assessment All students work in groups and carry out four experiments, however the assessments are all individually submitted. The students keep a log-book of the experimental observations and results, which is used for reference for the technical report from each experiment written-up in the week after the experiment.

  • EG-387 Metals: Advanced Manufacturing and Protection

    This module explores the link between fundamental science and advanced materials behaviour. The first section explores the use of computational modelling of the physics involved in many materials processing methods. Specific examples related to solidification and annealing are covered. The second section deals with the detailed chemical reactions occurring during the corrosion of metals, following on to explore methods of prediction and prevention. To extend students¿ ability to design and use materials by linking the engineering use of metalforming processes and chemistry (via design against corrosion).

  • EG-M113 Advanced Manufacturing of Metals

    The module will provide a deeper understanding of the physical principles underlying the processing of near net and net shaped technologies for advanced metal manufacturing. The course will cover casting, semi-solid metal manufacturing (Thixoforming), additive layer manufacturing and Powder Metallurgy for manufacturing. NOTE. Continuous casting methods will not be covered. The areas covered will cross cut the engineering disciplines of advanced manufacturing technology and material science to broaden the technical and industrial context of both conventional and advanced manufacturing for metals.

Supervision

  • TBC (current)

    Student name:
    EngD
    Other supervisor: Dr Mark Whittaker
  • Fatigue behaviour in novel titanium alloys (current)

    Student name:
    EngD
    Other supervisor: Prof Martin Bache
  • High Integrity Joining and Repair of Gamma TiAl (current)

    Student name:
    EngD
    Other supervisor: Dr Karen Perkins
  • Investigation into heat treatment of Weartech alloys (current)

    Student name:
    MSc
    Other supervisor: Prof Martin Bache
  • Alternative Joining Techniques for Ti alloy powder interlayer bonding (current)

    Student name:
    EngD
    Other supervisor: Prof Martin Bache
  • Materials and Mechanical Characterisation of Additive Manufactured Alloys for the Nuclear Sector (current)

    Student name:
    EngD
    Other supervisor: Dr Robert Lancaster
  • High Integrity Gas-Shielded Interlayer Joining Of Aerospace Alloys (current)

    Student name:
    PhD
    Other supervisor: Dr Mark Whittaker
  • Validation of a high integrity joining/repair process for aerospace applications (current)

    Student name:
    PhD
    Other supervisor: Dr Karen Perkins
  • Thermo-mechanical characterisation of a nickel super alloy (current)

    Student name:
    PhD
    Other supervisor: Prof Geraint Williams
  • Remnant Life Assessment based on the Small Punch Test and the Wilshire Equations (current)

    Student name:
    PhD
    Other supervisor: Dr Mark Evans

Career History

Start Date End Date Position Held Location
2015 Present Senior Lecturer Institute of Structural Materials, Swansea University
2011 2015 Senior Technical Manager ASTUTE, Swansea University
2001 2010 Various Technical Roles VALE (Nickel Refinery)
1998 2000 Research Officer Swansea University
1996 1998 Research Assistant Swansea University

Academic History

Date Qualification Location
1996 PhD Swansea University
1993 BEng Materials Engineering Swansea University

Research

Fatigue of Titanium alloys
Previous research has focussed upon low temperature dwell sensitivity in Titanium Alloys. During this period I pioneered the technique of Fracture facet orientation determination via Electron Backscatter diffraction (EBSD).  

Current work is focussed upon validation of a powder bonding technology previously developed at Swansea to support generation of a micro-mechanical models.

Investigation into the early stages of the bonding process are being studied using a combination of metallographic and volumetric characterisation methods (e.g. X-ray CT).

Grain Boundary Engineering.

Grain boundary engineering is an approach designed to control the properties of materials by controlling the grain boundary character distribution (GBCD), mainly by promoting a high proportion of so-called special grain boundaries in them. Through a systematic modification of GBCD,  mechanical properties such as strength, ductility, creep, and corrosion resistance can be improved.  Sequential thermomechanical processing (such as mechanical deformation by cold rolling/tensile straining),  followed by mid- or high- temperature annealing has been adopted to optimize microstructures, by increasing the fraction of special grain boundaries and breaking-up the interconnected random grain boundary network.

Research into GBE is now underway for Novel Aerospace alloys.

Semi-Solid Metal Joining.

Joining in the thixotropic state is considered to be an effective alternative joining method to welding because the material is processed when it is in a semisolid state between solidus and liquidus temperatures. Here the material shows thixotropic behaviour. Metal in a thixotropic state has many features such as high softness, good flowability, superb workability, and excellent join ability.

The key potential advantage of the semisolid joining of alloys is that it can avoid many of the problems (deterioration of the fracture toughness, corrosion resistance, and yield strength in the HAZ) because of the fact that the solidification and heat transfer processes are basically different from those of typical welding.

Nickel Manufacture

Ten years’ experience across a range of Departments within the Nickel Manufacturing Industry- Extensive knowledge of Nickel Powders/Pellets manufactured via Carbonyl Process.