Institute of Physics of Materials AS CR, v. v. i. > List of facilities > MTS 810 servo-hydraulic testing machine for fatigue loading at temperature range from -196°C up to 350°C

MTS 810 servo-hydraulic testing machine for fatigue loading at temperature range from -196°C up to 350°C

Testing system allowing us to perform isothermal fatigue loading at temperature 24°C or when equipped with cryostat at low temperature from -196°C or equipped with environmental chamber in temperature range from -70°C up to 350°C.

Computer-controlled fatigue testing machine with a capacity of ± 100 kN is equipped with a silent hydraulic pump/power unit (25 l / min) and two servo valves (25 l / min, 38 l / min). The electronic unit with software Teststar allows closed-loop testing under strain or stress control mode. Testing at low temperature (from -196 ° C) is carried out with the assistance of the cryostat, when specimen and the space around it are cooled with liquid nitrogen vapours. Environmental chamber can be used for testing in the temperature range from -70 ° C to 350 ° C. Temperate of test is measured using thermocouple placed on the specimen and it is controlled by controller in temperature range +-1°C. For gripping specimens of various shapes and sizes either water-cooled hydraulic grips can be used or mechanical grips suitable for low or elevated temperature. Deformation measurement at room temperature is performed using inductive extensometer. Measurement of deformation at elevated temperatures is carried out using a special capacitive extensometer. Applications: Determination of fatigue-life characteristics such as fatigue life curves, softening or hardening curves of different types of materials intended for applications operating at different temperatures (normal, reduced or elevated). The machine can be complemented by a long focal microscope which enables observation of the specimen surface during loading and thus monitoring of fatigue crack initiation, ie. studying the kinetics of fatigue damage.