Work Package 3 - Material Parameters
The material parameters of all three alloys will be measured and included into a material database as only incomplete data exists in the literature and as the material properties are changing if small changes in the chemical composition occur especially for the nickel-base and cobalt-base alloys. These material properties will be used for the simulations in WP4.(WP3.1) Temperature-dependent elastic properties are measured using the method of mechanical spectroscopy, e.g. the vibration reed set-up.
(WP3.2) Flow curves will be measured using standard equipment and the Hopkinson-Split-Bar set-up as a function of strain rate and temperature, namely between 20°C and 1000°C. (A) For low strain rates, standard compression tests using a servo-hydraulic testing machine will be performed (quasi-static conditions).
(B) Higher strain rates (up to 104 s-1) will be realised in Hopkinson-Split-Bar tests on standard cylindrical samples.
(C) As higher strain rates (up to 106 s-1) have to be reached, shear experiments on hat-shaped samples will be carried out using the Hopkinson-Split-Bar device.
The stress-strain curves will be calculated from the three different experiments. The resulting data will be used to determine constitutive flow-stress equations (flow laws).
(WP3.3) As thermo-physical properties are also needed, the heat conductivity, the heat capacity, the coefficient of thermal expansion and the density will be measured in the temperature range from room temperature up to 1000°C.
Figure 1: Testing of the high-temperature material properties of a Nickel-base superalloy.