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HOT ISOSTATIC PRESSING (HIP) OF ENGINEERING CERAMICS RELATED TO ENGINE APPLICATIONS - A CRITICAL APPRAISAL

Objective

THE OBJECTIVE OF THIS PROJECT IS TO DEFINE FOR CERAMIC MANUFACTURERS, CERAMIC USERS, AND MANUFACTURERS OF CERAMIC PROCESSING EQUIPMENT THE ADVANTAGES AND DISADVANTAGES OF HIP PROCESSING OF ENGINEERING CERAMICS.

TWO CLASSES OF MATERIAL WILL BE STUDIED : OXIDE CERAMICS AND NON-OXIDE CERAMICS, IN A NUMBER OF FORMS. THE OXIDE IS TRANSFORMATION THOUGHENED ZIRCONIA, PARTIALLY STABILISED WITH EITHER MAGNESIA, YTTRIA OR CERIA. THE NON-OXIDE IS SILICON BASED CERAMICS, INCLUDING SILICON NITRIDE AND SILICON CARBIDE.

CERAMIC WHISKERS OR FIBRES WILL BE ADDED TO A SELECTION OF THESE FORMULATIONS. EMPHASIS WILL BE PLACED MAINLY ON POWDERS AND CERAMICS CURRENTLY IN PRODUCTION OR AT AN ADVANCED STAGE OF RESEARCH AND DEVELOPMENT.THESE FORMULATIONS WILL BE MODIFIED TO TAKE ADVANTAGE OF THE HIP PROCESS SUCH AS THE USE OF REDUCED AMOUNTS OF SINTER ADDITIVES AND THE ABILITY TO DENSIFY FIBRE COMPOSITES.

THE CERAMICS WILL BE PREPARED USING CURRENT MANUFACTURING PROCEDURES SUCH AS POWDER PRESSING, INJECTION MOULDING, AND SLIP CASTING. THESE WILL BE USED AS A BASIS FOR COMPARISION. THE HIP PROCEDURES WILL BE BASED ON TWO VARIATIONS : GLASS ENCAPSULATION OF EITHER GREEN OR POROUS MATERIALS, AND SINTER-HIP OF GREEN MATERIAL. THE HIP STUDIES WILL INVOLVE THE STUDY OF A NUMBER OF THE MAJOR VARIABLES SUCH AS TEMPERATURE/TIME/PRESSURE CYCLES.MUCH OF THE WORK WILL BE CONDUCTED ON SMALL EXPERIMENTAL SAMPLES BUT LATER IN THE PROGRAMME IT IS PROPOSED TO STUDY LARGER DEMONSTRATION PIECES.

A MAJOR PART OF THIS PROGRAMME WILL BE TO COMPARE CRITICALY THE PROPERTIES OF MATERIALS MADE BY CONVENTIONAL ROUTES AND THOSE BY HIP.

THE PROPERTY ADVANTAGES THAT WOULD ACCRUE FROM HIP ARE ONLY VERY POORLY DEFINED AT PRESENT AND THIS PROJECT WILL GIVE MUCH GREATER DEFINITION. AT THE SAME TIME REALISTIC COSTINGS WILL BE PRODUCED FOR PROTOTYPE COMPONENTS BY CONVENTIONAL AND HIP TECHNIQUES SO THAT A REALISTIC ECONOMIC ASSESSMENT CAN BE MADE BY INTERESTED COMPANIES.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

United Kingdom Atomic Energy Authority
Address
353,Harwell
OX11 0RA Didcot - Oxfordshire
United Kingdom

Participants (2)

National Forge Europe
Belgium
Address
7,Industriepark Noord
9100 Sint-niklaas
Vlaamse Instelling voor Technologisch Onderzoek
Belgium
Address
200,Boeretang
2400 Mol