Dr. Ron Jones
Horizon Ceramics Ltd (UK)

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The beginning was January 1981 when
I founded Ceramic Developments Ltd
„ Long term was to develop new materials and products based on ceramics and glasses and find suitable licensees to carry out manufacturing
„ Short to medium term to offer contract development services to other businesses and support them during pilot and preproduction stage

Successful developments
„ Between 1992 and 93 we armoured over forty
Hercules C-130 aircraft which flew the supply drops in Bosnia on relief work in
Sarajevo…… 26 m 2 per aircraft at 26.4 kg/ m 2

We developed new heating element technology with a group of Partners
„ The principle was to screen print a metal track onto a glass-ceramic coated stainless steel plate then power this up. It has been adopted by many kettle manufacturers

„ We manufactured 150 tonne per year of special glass for the vitrification of high level nuclear waste

„ Make near net shape ceramics that do not shrink appreciably after firing.
„ Create enhanced strength through firing.
„ Find a way of increasing the durability of the ceramic.
„ Find a method of closing off surface porosity

The Freeze Gelation Casting
Process
„ Horizon began developing this process in
1993 for volume manufacture of precision ceramic components and commercialised several technologies including manufacture of refractories. The process is now operated, under license, by several divisions of Morgan
Crucible plc.

Installing plant at a licensees facility
„ The plant here shows a small tunnel freezer and large chest freezer

A plant built for volume manufacturing of refractories

Six years of technology transfer and product development have given this licensee a broad product portfolio

„ Possibly one of the largest volume manufacturing processes using nanotechnology.
„ Simplicity itself: mix—cast into mould— freeze—release—dry—fire
„ Can be used to make parts of any size from a wide range of compositions.
„ Typical shrinkage from mould to fired product…….0.2 %

„ Large components can be cast easily

Why are people wary about the use of ceramics for tooling?
„ Ceramics are brittle and weak in tension.
„ They fail in an unpredictable manner and often as catastrophic failure.
„ They will not take the treatment sometimes experienced on the factory floor; particularly of a part gets jammed in the die.
„ It is difficult to achieve a “net shape” ceramic after firing.

Adapting this process to the produce tooling
„ In the early stages a wide number of tooling applications were investigated including plastic and rubber injection moulding tools

„ Ceramic Tool on injection moulding machine moulding rubber clamps.

Many complex features may be cast in to a high precision

„ Compression moulds

Die Casting Tooling
Zinc Die Casting Tool Tool on Machine
Die Cast Parts

This composite tool was built in two halves

„ Both halves are fired simultaneously on a
Kiln Car

The tool section after impregnation
„ The surface has been infiltrated with chrome and silicon carbide

SLA Pattern RTM Tool Set. Core &
Cavity

„ The first stage was to test out the net shape capability of the freeze casting process.
„ This meant producing various types of patterns, forming parts and measuring the geometry.
„ At this stage the ambition for ceramic tooling aimed only at satisfying the need for providing the industry with a rapid prototyping system

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SPF is a high temperature forming process and ceramic materials provide stable working characteristics in this regime.
Many oxide ceramic compositions are chemically stable so there should be little reaction with metals at high temperature.
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Often they are non-strategic abundant materials, cost little and are easily formed.
Density is between 25 and 45 % of high temperature steels.

„ An early project with
UWE, BAe and Rolls
Royce demonstrated the potential of the freeze cast ceramic tools in SPF

„ This was built as a test tool for British
Aerospace
(Salmesbury) and proved successful in producing a number of titanium panels

„ Further tools have and continue to be built and this system appears to be a useful method for rapid prototype tooling

Development work with Boeing on
SPF Ceramic Tooling
The process is quite demanding on any material

„ There are several known ways that tough ceramics have been achieved: fibre reinforced ceramic matrix composites
„ Transformation toughening: as used in zirconia
„ Neither process offered commercial prospects for large tools and both were prohibitively expensive.

„ As ceramics without the toughening treatment this does make a useful rapid prototyping system.
„ Toughening will eventually produce a tooling system capable of being used in production.
„ Other application areas are now being examined such as SPF Press platens.

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All change: Ceramic Matrix Composites are to be revisited and contracts are in progress with
Boeing and about to start with Rolls Royce
The process chosen is Pyrolysis of Preceramic
Polymers
Three systems currently under development are
SiC/SiC SiC/C and Oxide/Oxide
The internal development is to use these materials to develop low mass, self heating composite tooling