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Introduction

Medium Range Temperatures

High Range Temperatures

INTRODUCTION   

If products have to operate under high temperatures, have to be light weight and have to maintain their strength under these conditions, composites can offer an ideal solution.

At UC we make a distinction between two types of high temperature performance composites. These are;

• Medium range temperature performance composites (up to approx. 300 º C)

• High range temperature performance composites (up to approx. 900 °C)

MEDIUM RANGE TEMPERATURES                     TOP  

For temperatures up to approx. 320 ºC certain advanced reinforced plastics offer a solution. This is for thermo set as well for thermoplastic based composites.  In particular the temperature resistance of the matrix (resin) determines the preservation of the mechanical habits of the composite part. Also the difference between the thermal expansion coefficients of the matrix and the fibre, and between the laminate layers, have to be optimised towards the operating and surrounding temperature of the part. The most used matrix and fibre systems are mentioned below;

Matrix systems

A        Thermo set 

• phenol resins ( max. 150-230 º C)

• special epoxy systems (phenol novolac max. 230 ºC)

• bismaleimide resins (BMI) ( > 230 ºC, better mechanical habits than epoxy at high temperatures)             

• polyimide resins (condensation type / PMR15 > 315 º C).

B        Thermoplastics

• PEI

• PEEK

High tech fibres  

• glass fibre (E, S and quartz glass)

• aramide (TWARON/KEVLAR)

• boron fibres

• carbon / graphite (HT and HM carbon)

Examples of applications are;  engine parts surrounding the hot area's of the engine, pipes for hot gasses/liquids, exhaust parts, insulations parts, etc.

HIGH RANGE TEMPERATURES                              TOP

It is possible with composites to make parts with an even higher temperature resistance than is possible with the above mentioned plastic matrix composites. In this case the plastic matrix is replaced by a metal or light metal matrix and are called Metal Matrix Composites (MMC's). The fibres (reinforcement) commonly used in this type or composites are the boron, graphite and the silicon carbide fibre (SiC).  Examples are: the high gain antenna for the Hubble space telescope (graphite reinforced aluminium) and fins for guided missiles (SiC reinforced aluminium). MMC's have in general operating temperatures around the 500ºC.

If parts have to operated at even higher temperatures the matrix but also the fibre can be replaced by glass or ceramics. These type of composites are called "glass matrix composites", "ceramic matrix composites", ceramic/ceramic composites and the ceramic fibre composites. Other possibilities are to carbonise the matrix (mostly phenol) of a carbon/graphite composite. These type of composites are called carbon-carbon composites and are used for by examples in brake disks of aircraft or Formula 1 / Indy race cars. These type of composite can operate at temperatures up to approx. 900ºC or higher.

!!!    United Composites focuses mainly  glass matrix and de ceramic matrix composites. (Example: SiC fibres used  in SiC/glass composite. Production method "hot-pressing". Result laminates with a temperature performance (long term)  up to 900 ºC. 

Matrix systems

• aluminium

• glass

• ceramics (AL2O3, ZrO2, Si3N4, SiC).

• carbonised phenol

High tech fibres

• boron fibre

• carbon fibre (HT carbon)

• graphite fibre (graphite HM carbon)        

• ceramic fibres (SiC)

Some Examples