A5012934013- Advanced materials and composites
- Aluminum Alloys Composites Properties
- Powder Metallurgy Techniques and Materials
- Advanced ceramic materials synthesis
- Metal and Thin Film Mechanics
- Advanced Materials Characterization Techniques
- Microstructure and Mechanical Properties of Steels
- Metallurgy and Material Forming
- Intermetallics and Advanced Alloy Properties
- High Temperature Alloys and Creep
- Aluminum Alloy Microstructure Properties
- Metal Alloys Wear and Properties
- Tunneling and Rock Mechanics
- Metallurgical Processes and Thermodynamics
- Fatigue and fracture mechanics
- High-Velocity Impact and Material Behavior
- Metallurgical and Alloy Processes
- Advanced machining processes and optimization
- Microstructure and mechanical properties
- Advanced Surface Polishing Techniques
- Non-Destructive Testing Techniques
- Hydrogen embrittlement and corrosion behaviors in metals
- Metal Forming Simulation Techniques
- Titanium Alloys Microstructure and Properties
- Diamond and Carbon-based Materials Research
National Physical Laboratory
2014-2023
Teddington Memorial Hospital
2006-2023
Massachusetts Institute of Technology
1972-1975
Case Western Reserve University
1975
University of Manchester
1972
Institute of Science and Technology
1972
Deformation and fracture processes have been examined in WC–Co tool materials, still the most commonly used hardmetal. The relevant microstructural parameters are described detail an assessment is made of their effects on strength tests at ambient temperature, for constituent phases separately combination. results properties more to service behaviour, such as fatigue creep, summarised. Finally, recommendations with regard need further fundamental research.
A series of experiments investigating the recrystallisation single crystal superalloy CMSX-4 have been carried out. Indentation atroom temperature has used to study effects annealing time and temperature, it found that a very strong dependence upon is evident. Annealing above γ′ solvus results in rapid growth recrystallised grains whereas below greatly suppresses advancing grain boundaries. Additionally out using an electrothermal mechanical test (ETMT) machine, degree plastic strain at...
This paper describes good practice for the measurement of hot flow stress in metallic materials. It is applicable to (isothermal) uniaxial axisymmetric compression tests at medium high rates strain (10−4–102 s−1) deformation temperatures below solidus.Guidance provided on appropriate testpiece geometries and methods verifying temperature distribution along length testpiece. Flow diagrams are given showing all steps that necessary, including correction factors need be applied deformational...
A supersaturated γ phase microstructure is produced in Ni-based superalloys using laser powder bed fusion (L-PBF) – the cooling rate arising from process shown to suppress solid-state precipitation of γ′ phase. The response material a heat treatment therefore requires new understanding at fundamental level, since first population precipitate forms upon heating, contrast homogenisation above solvus. Here, we have interrogated two nickel-based designed for L-PBF technology, both situ and ex...
The wide scatter in the results of transverse rupture test on specimens hardmetals same grade, and overlap tests different grades, have. been rationalized by examining fracture surfaces individual specimens. It is found that a major reason for usually initiated at pores other defects various sizes, stress depends defect size according to Griffiths-type relation. This observation considerations concerning position initiation site are used provide quantitative explanation tests; it shown due...
Testing in the microregime is relevant to many technological issues, including, for example, evaluating performance of established plant or new components through removal small scale samples; assessing point variation welded structures; characterising expensive advanced alloys that typically are only available quantities; and testing subsized components. The use miniature testpieces requires attention underlying microstructure relative overall testpiece dimensions, presents challenges...