RA5a: Structure,environment and staffing policy(i) Overview
The Department of Engineering Materials was rated 5*A in 1996. Since then it has enhanced its international-level research in all existing areas of activity and expanded two areas which were in their infancy – electroceramics and tissue engineering - through key external professorial appointments and associated lectureships. The Dept has much higher levels of research income (average £2.54M pa cf £1.75M pa), PhD awards (24.2 pa) and publications (155 pa) than in 1996 and has established two spin-off companies. All staff have a high level of research activity for which the large majority have international reputations. Research falls into three major groupings: Ceramics and Glass, High Performance Metallics and Process Modelling and Polymers and Polymer Matrix Composites, each of which incorporates many sub-themes. We are in the premier group of UK Materials Depts for EPSRC funding (£8.09M for current grants at 12/3/01, EPSRC web page) and are unique in having international profiles in the whole range of structural materials (metals, glasses, ceramics, polymers, composites) and in wide ranges of both functional materials and molecular and biological materials. During the review period eleven members of staff were on the EPSRC Materials College and MacNeil is on the BBSRC Engineering and Biological Systems panel.
At RAE 96, we had just completed transfer of our non-metals facilities to form a fully integrated Dept. With the increased collaboration that followed, research flourished and each group operates at an internationally-recognised standard of excellence, concentrating on promoting strengths and identifying future themes. A most pleasing aspect is the eminence achieved by all staff, as evidenced by promotions to senior posts within the review period of Atkinson (R), James (P), Lee (P), Rainforth (P), Reaney (SL), Seddon (R), Short (R), Sinclair (SL), Ungar (R), Wright (R). The Dept has improved its staff age profile and has an excellent distribution of senior/junior staff numbers with 8 staff, including 6 professors, in the 55-65 age range, 6 staff, including 4 professors, in the 40-54 age range and 8 staff, including 3 in promoted posts, under 40. Our research effectiveness and productivity is at a very high level with excellent rates of PhD supervision, publication and research income as shown below:
The number of postgraduate students has been maintained at a healthy average of 75.4 pa (excluding students writing up). An average of 11 MSc and 7 IGDS (MSc) research projects were supervised pa. The number of Research Associates and Visiting Scientists averaged 43 pa. For 2000, for instance, the average number of researchers supervised was 6.7 per fte academic. Annual income is on a firm upward trend and now averages >£3M pa; i.e. ~£150k/fte. Approx 16% of our research income comes from industry, with the involvement of 24 companies over the 96-00 period. All staff, apart from those appointed in the last 9-15 months, are principal investigators on substantial research grants. 6 major texts and 4 proceedings have been written or edited including the 2nd edition of the major text book Basic Solid State Chemistry by West (1999), leading to combined worldwide sales of >20,000, and a monograph on Basic Optical Stress Measurement in Glass by Hand. 15 chapters in books have been written and 3 patents filed in the tissue engineering/plasma polymer fields.
(ii) Achievements in Relation to Objectives
For RAE 96, we set out objectives according to six main themes. These have all been achieved and, in most cases, surpassed. Thus:
1. The Ceramics Research Group has retained its strong base in traditional structural ceramics, including refractories, cements and whitewares, but has expanded greatly into functional materials, especially electroceramics, through chair (West) and lectureship (Sinclair) appointments. These complement existing strengths of Reaney and Lee in processing and microstructural characterisation with expertise in synthesis of new materials, phase diagram and structure determination and electrical property measurements; effectively, this has allowed us to bridge the materials-chemistry interface.
2. The Centre for Glass Research, established in 1996 (Director James), has invigorated interdisciplinary glass research within the University through links with Chemistry, Physics, EEE, Appl. Maths, Restorative Dentistry and Archaeology and has led to significant industrial collaboration and sponsorship.
3. The Centre for Advanced Magnetic Materials and Devices has a strong track record for interdisciplinary research with Physics and EEE and has developed leading nanoscale engineering of magnetic materials, in particular, nanocomposite bulk hard and soft magnetic materials (Davies). Thin film research has covered film growth through to device development (Rainforth, Davies, Gibbs-Physics). Advances in magnetic force microscopy, both in terms of image interpretation and tip development, are world-leading (Rainforth, Davies, Gibbs, Tucker, Bishop -Physics).
4. The Metals Processing and Process Modelling Research Group has established IMMPETUS (Institute for Microstructural and Mech Process Eng; University of Sheffield) through a 5-year, £2.75M EPSRC grant to this Dept (Sellars, Rainforth, Palmiere) in collaboration with the Depts of Mech Eng - Beynon and Automatic Control and Systems Engineering (ACSE) - Linkens, and has received an additional £2.2M of which £500k is from industry. Two new companies, Thixoforge (Director: Atkinson, 2000) and Vforge (Director: Kirkwood, 2001) have been launched to build upon our semi-solid processing expertise which, together with longstanding expertise in solidification processing, powder processing and rapid solidification of high performance alloys, has achieved wide international recognition (Davies, Jones H). One industrially-sponsored (CORUS) lectureship has been filled (Palmiere); we have agreed terms with an internationally-recognised person for the POSCO chair currently held by Sellars (the name is confidential at the time of the submission), and an associated lectureship will be filled in the near future.
5. The Polymers and Polymer Composites Group has new appointments in aerospace composite materials (Hayes) and polymer biomaterials (France, Haycock). A new initiative in Tissue Engineering (Centre for Biomaterials and Tissue Engineering (1997), with van Noort, Dental School, as Director) has led to a joint Chair appointment with the Medical Faculty (60% Eng Mats, 40% Medicine, MacNeil) and an associated lectureship in Eng Mat (Haycock). This brings together research involving 10 University Depts. The engineering of polymer substrates for tissue culture of skin cells for clinical trials in wound healing led to the Dept’s spin-off company Celltran (Directors: Short, MacNeil, 2000). Hayes is also associated with the new Aerospace Engineering Division, involving Eng Mats (Jones H, Jones F), with Mech Eng (Tomlinson), ACSE (Fleming), EEE (Chambers) and Computing (Holcombe). This illustrates the genuinely-enhanced, collaborative environment which exists in the Faculty of Engineering, arising from its overall excellent performance in RAE 96.
6. The Sorby Centre for Electron Microscopy has been enhanced through acquisition of a FEGTEM (Rainforth, Lee with Cullis, Whitehouse, EEE, cost £1.1M; our proposal came first in the ‘High Value EM’ EPSRC call) and FEI Tecnai TEM (£360k). Since the last RAE we have spent over £2.5M (from various sources) on major new pieces of equipment including a plane strain compression machine (£600k), a nanoindentor (£250k), a 9Tesla VSM (£130k), a Stoe powder XRD system (£100k) and a fluorescence and a confocal microscope (£80k). Approx £300k has been spent on refurbishment to give new laboratory space (for electroceramics, tissue engineering) and improved study space for PhD students and PDRA’s.
(iii) Current Environment and Research Activities
We continue to be one of the largest and most productive Materials Depts in the UK with an excellent balance between metals, non-metallic inorganics and molecular/biological materials.
a) Ceramics and Glass (Hand (L), James (P), Lee (P), Parker (R), Rainforth (in part) (P), Reaney (SL), Sharp (P), Sinclair (SL), West (P), Cable (Emeritus, P))
Research in this area has a distinguished history, in separate Depts of Glass Technology and Refractories. These key aspects are still retained but Cement and Concrete and, more recently, Electroceramics have been added to form an internationally recognised and vibrant research group comprising 4.5 professors, 1 reader, 2 senior lecturers, 1 lecturer and currently 13 RAs, 34 PhD students and 9 research visitors.
Research in traditional ceramics applies new techniques to refractory-slag interactions and microstructural evolution in vitreous ceramics using transmission electron microscopy (Lee) to understand the mechanisms underlying cement durability (Sharp) and develop novel whiteware processing routes (Hand, Messer). Advanced ceramics research, including electroceramics, glass-ceramics, CMCs and structural oxides is of the highest international standard. Recent highlights include synthesis of new oxide ion conductors (eg NaBi3V2O10, Sinclair) and new cathode materials based on LiCoMnO4 for operation at a record 5V in rechargeable lithium batteries (West). A novel mechanism of doping BaTiO3 by La has led to very high permittivities (~36,000) at room temperature. Presently the change-over from first order to relaxor behaviour is being studied (Sinclair, West), building on innovative work to characterise electrical microstructures using impedance spectroscopy. Reaney is known internationally for establishing correlations between tilting of octahedra in perovskite-related structures and the temperature coefficient of permittivity, an important parameter for microwave device applications. The combined use of HREM (Lee) and defect calculations (Grimes, Imperial) to characterise the structure of planar defects in electroceramics (such as IDB’s in ZnO and Ruddlesden-Popper phases in SrTiO3) was the first such study, an approach being copied by several groups in Japan and the USA. The determination of fundamental crystallization mechanisms in aluminosilicate and phosphate glass ceramics (Lee, James, Reaney) has led to improved bone replacement materials and collaborative research with Kokubo at Kyoto University, Japan.
Glass research concentrates on special processing routes (sol-gel, coatings, fibres, controlled-atmosphere melting) and novel compositions with tailored properties, including chalcogenides and fluorides for telecommunications (Hand, Parker), biocompatible glass-ceramics (Hand, James, Reaney with Restorative Dentistry), durable glasses and cements for radioactive and toxic waste immobilisation (Hand, James, Sharp) and retains significant industrial links in traditional process-based research (Cable, Parker). Much is supported by studies of nano- and micro-structural development using high resolution TEM, XRD and neutron-diffraction (James, Lee, Parker, Reaney). We shall host the Int Symp on Crystallisation in Glasses and Liquids in 2003 and are major contributors to the organisation of ICG2001, Edinburgh.
Some of the many international collaborations of the Ceramics and Glass Group include those of Sinclair with Takeuchi (ONRI, Japan) on spark plasma sintering, Reaney with Randall at Penn State, USA on microwave dielectrics, Lee with Nan (Wuhan Univ, China) on castable refractories, West with Sanz (CSIC, Madrid) on solid state NMR of Na+ ion conductors, James with Granasy, (Solid State Physics Research Inst, Budapest, Hungary) on glass crystallisation, Rainforth with Kato (Tohoku Univ, Japan) on wear of ceramics, Sharp with Tsivilis (NTU, Athens, Greece) on durability of cements, Hand with Sigel (Rutgers, NJ, USA) on glass extrusion, Cable with Karlsson (Åbo Akademi, Finland) on models for composition/property relations in silicate glasses and Parker with Dmitruk, (General Physics Inst, Moscow, Russia) on scintillating fluoride glasses.
b) Polymers and Polymer Composites (France (L), Haycock (L), Hayes (L), Jones F (P), MacNeil (P), Short (R), Ungar (R), Wright (R))
Research in polymeric materials is diverse and innovative. New achievements include record high ionic conductivities in the polymer electrolyte field (Wright), new mechanisms of polymer crystallization (Ungar) and new directions in composites (Jones F, Hayes) and biomaterials (MacNeil, Short, France, Haycock) research. The group has 2 professors, 3 readers and 3 lecturers with 12 RA’s and 26 PhD’s. Wright, who has the accolade of the discovery of electrical conductivity in polymer electrolytes (Faraday time chart of Electrochem Society), has developed a novel, low-dimensional approach to polymer electrolytes which has given rise to record Li+ conductivities at low temperatures for electrochemical devices such as batteries and, in a major collaborative programme with EEE (B Chambers), switchable mixed conductors for microwave-active surfaces have been developed.
Ungar has provided the impetus for the discovery of how well-defined molecular elements can be organised into new morphologies within polymer and liquid crystals. A recent highlight of this work, undertaken in collaboration with groups in the USA (Percec et al.), Japan and Leeds, is the self-poisoning model for long chain hydrocarbon crystals which provides the explanation for crystal thickening and chain folding in lamellae. His work introducing liquid crystal dendrimers, molecular self-assembly and suicidal crystals has featured strongly in Nature and Science.
Research into fibre-composite interfacial chemistry and mechanics has led to a new method of assessment, and the molecular engineering, of the interface using conformal plasma polymer coatings of controlled chemical functionality (Jones F). Elastic-plastic FE modelling has shown how interphase design correlates with global properties (Jones F, Hayes), and leads to an innovative constrained layer damping technology which uses sequential deposition of a soft plasma polymer and plasma ceramic (Jones F, Tomlinson (Mech Eng)). Linking polymers through to biological sciences, Short was one of the first to realise the capability of plasma polymerisation to fabricate films incorporating very specific chemistries. Plasma polymerisation is the platform technology that forms the basis for CellTran and a number of other recently-initiated tissue engineering projects.
France was involved in early ground-breaking studies of interactions between these polymers and cells and biofluids; MacNeil and Haycock’s recent appointments extend this work into tissue engineering. MacNeil has 25 years experience in investigating how human cells respond to external environments and nearly 10 years experience in the development of reconstructed human skin for clinical use. Her joint appointment with the Medical Faculty (60% Eng Mat from Jan 2001; for this RAE she is returned under Medicine) reflects the interdisciplinary nature of tissue engineering and will aid translation of pure research to clinical application, as demonstrated by funding from the White Rose Partnership (York, Leeds and Sheffield: Venture Capital Fund) and Wellcome for Celltran (£230k since its launch in 2000, Short, MacNeil) to develop defined surfaces for production of "biological bandages" of patients' skin cells grown and expanded on these surfaces and then transferred to wound beds for burns or non- healing ulcers.
The recent formation of the Sheffield Polymer Centre (currently 27 staff members in Eng Mat, Chemistry (especially Ryan and Hunter), Physics (especially Jones R) and other Eng Depts) has the clear intent of promoting novel cross-disciplinary research between science, engineering and medical disciplines. Evidence of the early success of this interaction is the recent EPSRC award of £336k to Ryan, Hunter (Chemistry), MacNeil and Haycock and a funded studentship for a study of wear in polymers (Dwyer-Joyce, Mech Eng, Jones F).
The many international links can be demonstrated by joint publications e.g. Jones F with Verpoest (KU Leuven) on interphase micromechanics, Short with Hanley (University of Illinois, Chicago) on ion beam surface modification, Ungar with Percec (Univ Pennsylvania) on self-assembling lattice structures; membership of networks e.g. fragmentation Round Robin Jones F with Drzal (Michigan State Univ, USA) and Hunston (NIST, USA), the European Interphase group led by Maeder (Inst Polymer Research, Dresden) with Hayes and Jones F; and experimental collaborations such as Short with Timmons (Univ Texas, USA) on pulsed plasma polymerisation, Wright with Thomas (University of Uppsala, Sweden) on devices from electroactive polymers and MacNeil and Haycock with Picardo (San Gallicano Dermatological Inst, Rome) and Ghanem (Free University, Brussels) on antiflammatory/antioxidant actions of Melanocyte Stimulating Hormone in skin cells.
c) High Performance Metallics and Process Modelling (Atkinson (R), Davies (P), Jones H (P), Palmiere (L), Rainforth (in part) (P), Sellars (P), Greenwood (Emeritus, P))
An exemplary history of metallurgical research and teaching extends back for over a century. Currently there are 3.5 professors, 1 reader, 1 lecturer, 12 RA’s, 28 PhD’s and 2 visiting scientists.
In the short time since its establishment, IMMPETUS (Co-Directors Sellars, Rainforth, Beynon, Linkens) has gained an international reputation for integrated, multidisciplinary work on thermomechanical processing, with an ultimate aim to develop through-process, physically-based models with realistic predictive capability. Our approach is international and unique: an integrated capability to generate basic data and understanding, apply a range of modelling methodologies and validate the outputs using laboratory processing before transfer to industry. We have been instrumental in identifying strain path as the critical issue in thermomechanical processing, since it controls microstructure and mechanical properties, requiring quantification and inclusion in models of microstructural distributions varying in space and time, and now have a clear international lead.
In addition to spinning off two companies, Atkinson has led a major multi-industrial partner EPSRC collaboration with Ridgway (Mech Eng), on manufacturing costing, and currently leads three EPSRC projects; two in thixoforming on the modelling of thixotropic flow in the semi-solid state (with Chin, Mech Eng) and one in developing thixoforming alloys for light weight aerospace components. Sheffield hosted the 4th Int Semi-Solid Processing Conf in 1996. Internationally leading research on solidification microstructure selection mapping has continued apace, providing a testbed for solidification theory as well as essential design information for developers of alloys and manufacturing processes. Its scope has broadened to include nanocomposite alloys and a wide range of non-equilibrium processing techniques covering bulk metallic glasses (Davies, Jones H) and novel nanophase light alloys for next-generation aerospace alloys (Jones H). Powder processing is increasingly a major activity, boosted by recent acquisition of a water atomisation plant and a 40 tonne machine for powder injection moulding of advanced alloy compositions (Davies), both fully funded by industry.
The magnetics activity in nanophase ‘ultra-soft’ and ‘ultra-hard’ bulk magnetic materials (Davies, Gibbs), only one of two such groups in each of these areas in the UK, has developed several new materials, engineered at the nanoscale for applications in magnetic devices. This work continues to define the state-of-the-art of magnetic material properties and mechanistic understanding, aided by collaborative micromagnetic modelling and magnetic force microscopy (Rainforth, Davies). The group has the UK’s only facility (and 1 of only 2 in Europe) for casting amorphous alloy wires which are vitally important for next-generation magnetic sensors. Unique equipment for accurately measuring creep strains at low stresses has been combined with AFM and SEM studies to verify formation of deposition zones at grain boundaries transverse to the applied stress, fully consistent with operation of diffusional creep (Jones H, Greenwood). Exceptional wear performance has been developed in 5056 Al/alloy/silicide reinforced MMCs in comparison with state-of-the-art Al alloy/SiC reinforced MMCs and spray formed hypereutectic Al-Si alloys. Unprecedented thermal stability at 600ºC has been developed in mechanically alloyed/reaction synthesised P/M Al alloys stabilized by coarsening-resistant nanophase Al4C3 and Al2O3 dispersions (Jones H, Rainforth).
Our research is underpinned by world-class characterisation facilities. These include a FEGTEM for quantitative chemical analyses at the ~1nm scale, structure imaging to a resolution limit of ~0.1nm, and atomic bonding information through the fine structure of electron energy loss spectroscopy from areas of ~1nm size. We have developed spectroscopic imaging to obtain a resolution limit of <1nm for precipitates, (e.g. Nb(C,N), embedded in a TEM sample, providing size distribution information previously available only through atom probe studies. We focus on the acquisition of statistically-meaningful data at the microscopic scale, crucial for providing the basic microstructural building blocks (internal state variables) for predictive model development. We are unique in combining high resolution texture information with specific thermomechanical processing history and a range of modelling methodologies. Our data are linked, via statistics of the extremes, to industrially-realistic volumes of material (Atkinson, Sellars, Anderson (Statistics), Yates (Mech Eng)).
The High Performance Metallics and Process Modelling group has strong world-wide links, including joint publications of, for example, Atkinson with Lopez-Cuevas (Unidad Saltillo, Mexico), Davies with Correia (INETI, Portugal) on rapidly solidified copper alloys, Jones H with Lieblich (CENIM, Spain) on novel Al-alloy-silicide MMCs, Palmiere with DeArdo (Univ Pittsburgh, USA) on thermomechanical processing of microalloyed steels and texture development, Rainforth with Hofer (Technical Univ, Graz, Austria) on electron spectroscopic imaging of strain induced precipitates and Sellars with Van der Zwaag (NIMR, Delft Univ, Netherlands) on thermomechanical processing of steels.
d) Interdisciplinary Activity
The ethos of collaboration extends beyond the Dept into various interdisciplinary research centres. The Dept is a major partner in 8 of these: the centres for Advanced Magnetic Materials and Devices (Davies, Rainforth + Physics and EEE); Cement and Concrete (Sharp, Hand + Civil Eng); Glass (James, Hand, Parker + several Depts); The Sheffield Polymer Centre (Jones F, Ungar, Wright, Hayes + Chemistry, Physics, Mech Eng + others); IMMPETUS (Sellars, Rainforth, Atkinson, Palmiere + other Eng Depts); Structural Integrity (Jones H, Greenwood + Mech Eng); Biomaterials and Tissue Engineering (MacNeil, Short, France, Haycock + Depts in Medical Faculty and Chemistry); Aerospace Engineering (Jones H, Jones F, Hayes + other Eng Depts), all of which provide the focus for interaction with academics of complementary expertise in other Depts.
(iv) Staffing and Research Student Policy
Although 5 of the professoriate retire within the next five years, each area has at least one younger professor and at least two other research-active staff of age 40 or less. University and Departmental policy is to replace retiring professors with a junior appointment (other than for the POSCO Chair) in a similar research area in advance of retirement. We do not appoint junior staff to ‘green field’ areas but to activities where suitable infrastructure and support from senior staff can be provided. New initiatives, such as electroceramics and tissue engineering, are achieved by external professorial appointments and associated lectureships.
The University has a mentoring policy for new staff appointees which enables their research to be rapidly established. This includes individual support from a senior academic, help with grant preparation, awards from Departmental discretionary funds and priority over Departmental funds for new facilities. Thus, France (mentor Short) received £60k to establish a tissue culture laboratory, Hayes (mentor Jones F) has £24k to promote research into smart composites and Haycock (mentor MacNeil) has a starter grant of £10k to develop further the tissue engineering laboratory. They are assigned light teaching (typically 1 lecture course) and administrative loads during their probationary period. Since all new staff also belong to one of the interdisciplinary research centres, they develop a positive approach to collaborative research from the outset. The University’s Staff Development Unit runs courses for all, but especially new staff, on career development, project management and research supervision. Each member of academic, research and technical staff has the opportunity of annual appraisal-type reviews with research performance and future plans a major component for academic staff.
A Postgraduate Committee has responsibility for monitoring the progress of all research students, through annual reports, oral examinations, poster presentations and Departmental and Faculty research student conferences. Students are examined by staff other than their immediate supervisor and all parties agree on the content of progress reports, which are subsequently submitted to the Departmental and Faculty postgraduate committees.
A Departmental Research Committee stimulates new activity and collaborative projects; it consists of younger research-active academics in each of the major research groupings, the senior academic with responsibility for research student selection and admission and is chaired by a professor. Research activity is promoted through the usual mix of group meetings, seminars and conferences and, additionally, through interactions with invited international academics and industrialists and the hosting of international conferences in Sheffield. The Dept’s Industrial Liaison Committee, which consists of eminent industrial scientists and engineers, and the University Research Committee, monitor the research effort through comment on the Dept’s Annual Report and its supplement, Research in Progress.
The research ethos of the Dept extends to members of the technical staff. Bagshaw, Lacey and Smedley are registered for part-time research degrees; Smedley (with emeritus Prof Cable) has maintained the Dept’s interest in archaeological glass artefacts through collaboration with the highly research-rated Dept of Archaeology and Prehistory (Jackson).
We achieved a 5*A rating in RAE 96. The Dept is now stronger on several fronts. At least three quarters of the staff have clear international recognition for research. We have no staff in the sub-national category. Two external, mid-career Chair appointments have both strengthened and diversified our research base. Our age structure is good and there is a clear policy to support our strengths with new lecturer recruits. We have increased output in key areas, in particular, research income, PhD awards, publications and invited conference presentations. The three main research themes have clear international distinction and our future strategy is to extend these in new directions, with much scope for interdisciplinary collaborations. We shall build on our already-strong and vibrant industrial links and encourage technology transfer.
Copyright 2002 - HEFCE, SHEFC, ELWa, DEL
Last updated 17 October 2003