Pneumatic servo-controlled material testing device capable of operating at high temperature water and irradiation conditions

摘要

Special requirements set for the constructional materials used in energy production have strongly influenced the challenges in the component design work. Many material parameters such as corrosion, fracture mechanics, fatigue and oxide films are needed as input data for such work. The generation of reliable data calls also for more sophisticated testing systems. The newly developed pneumatic loading technology (patented in Finland and international patents pending) provides important potential benefits and has already been successfully applied to testing many kinds of materials in different test environments. As the moving parts that penetrate the pressure boundary are not needed, the friction force at the sealing element location is avoided. Therefore the load control with pneumatic loading unit is more accurate than with the conventional servo-hydraulic devices. This enables testing of small size samples which is an advantage e.g. when testing irradiated materials or testing materials inside the reactor core of a nuclear power plant and especially in determining environmentally assisted crack growth rates of structural materials. Furthermore, the new design enables simultaneous testing of several samples, which helps produce more reliable statistical data in a more economical way.