Ceramics at TWI

Ceramics group personnel

Staff

	John Fernie John is Manager of the Ceramics Group at TWI, with responsibility for developing the use of ceramics in industry. Projects for power generation have included work on metallic and ceramic heat exchangers, ceramics in gas turbine engines and renewables.
	Paul Jackson Paul joined TWI in 2000 with a PhD investigating powder metallurgy and is a Senior Project Leader in the Ceramics Group. He has managed projects involving joining a wide variety of ceramics and high temperature materials using brazing and diffusion bonding. Also, he is working on the development of several TWI innovations such as Barrikade, sol-gel coating technology and high temperature refractory materials for applications in the power generation sector.
	Alan Taylor Alan joined TWI in 1995 with a PhD in Physics from Warwick University. As a Principal Project Leader in the Ceramics Section of the Advanced Materials and Processes Group he manages projects on the use of ceramics and glasses, ceramic-to-metal joining and sol-gel derived ceramic coatings. Alan has been closely involved in TWI's sol-gel coatings and nanotechnology activities. He is on the scientific advisory panel for a number of conferences in this area. His activities span a wide number of industrial sectors and involve a number of different coating technologies and end use applications.
	Alec Gunner Alec joined TWI in 2002 with an MA in Natural Sciences from Cambridge. He also has industrial experience in PEM fuel cells and OLED displays, including hydrolysis deposition, thin film metal PVD, spin coating and photolithography. As a Senior Project Leader in Ceramics, Alec is involved in TWI's interests in fuel cells and ceramic coatings, particularly transparent conducting materials. Alec also has experience in photolithographic patterning and etch chemistries for display fabrication, together with knowledge of jig and tool design and prototype pattern making.
	Anne Cline Anne joined TWI in June 2002 as an administrator for the Ceramics group. Prior to joining the team she has travelled the world whilst serving in the RAF and also has considerable knowledge of telecommunications.

Post Graduate Training Partnership Students

Cara Mulcahy
Fabrication and properties of phosphate matrix composites
Supervisors: Dr A. Taylor (TWI), Dr W Clegg (CU)

There is demand from the electronics industry for new substrate materials in integrated circuits (IC). The aim is to conduct (and dissipate) heat away from the semiconductor devices more effectively, so providing better 'thermal management'. The aim of this project is to establish methods for the manufacture of aluminium phosphate composites containing carbon-fibres. Such a composite would possess very high thermal conductivity and low thermal expansion, both of which are highly advantageous to industry.

Russell Goodhall
The Thermomechanical Properties of Heat Resistant Porous Materials
Supervisors: J. Fernie (TWI) and Prof W. Cline (CU)

The main focus of this work is a material called Barrikade ^® , which was invented and developed at TWI. This material combines low density and excellent fire resistance, and is used as a core material in fire doors. Work has involved developing procedures to characterise this material's properties, including the mechanical performance, creep behaviour, thermal conductivity and coefficient of expansion. The investigations also have input to the further development of Barrikade ^® to enable optimisation of properties for specific applications.

Douglas Conquest
Brazing of alumina using a Ni-Cr-Si-Ti alloy
Supervisors: L. Ecclestone (TWI) and Dr K. Knowles (CU)

The applications that exist for ceramics at high service temperatures are often compromised by the lack of suitable joining techniques. The principal aim of this study is to develop a braze system to join alumina that would allow bonds to be applied at service temperatures higher than those of the commonly used silver-copper-titanium brazes, i.e. above 400°C.

A Ni-Cr-Si-Ti braze was selected as the system possessing the greatest potential from the range of alloys examined. The braze system was modified by the addition of ceramic particles as a reinforcing phase to create a metal-matrix composite.

Transmission electron microscopy, scanning electron microscopy and energy dispersive x-ray analysis of ceramic-braze systems, together with flexural strength testing, have been used to characterise these systems. Useable levels of strength were measured up to 1000°C.

Ton Van Helvoort
Characterisation of interfaces formed in solid state bonding of dissimilar materials
Supervisors: Dr J Fernie (TWI), Dr K Knowles (CU)

The primary aim of this project is to specify the mechanism of electrostatic bonding and establish how the process might be improved and extended to other dissimilar materials. In the first experiments Si/pyrex electrostatic bonds have been made successfully and specimens from these bonds have been prepared for transmission electron microscopy (TEM). The project may be broadened to examine interfaces in other ceramic-metal combinations produced in the solid state by friction welding.