Thermophysical property measurements of standard materials and industrial steels: On the ground and on board of parabolic flights
Peter Pichler
Institute of Experimental Physics, TU Graz
15:00 - 15:30 Tuesday 04 February 2020 P2

Knowledge of thermophysical properties of complex alloys like industrial steels are of fundamental importance in our daily world. Airplane turbine blades, car engines or parts of nuclear reactors are only some of the products that are dependent on computational simulations and modelling to ensure a flawless production and durability. For the models to be developed and the simulations to be tested, experimental data of properties like density, enthalpy, surface tension or viscosity as a function of temperature, especially in the liquid phase, are needed.

In collaboration with the National Institute of Standards and Technology (NIST), a standard reference material for an AISI 316L stainless steel was characterized. Our experimental data are used by modelling experts in the U.S. to describe laser absorptance and additive manufacturing. The methods used are our ohmic pulse-heating setup (OPA), a dynamic scanning calorimeter (DSC) and an electromagnetic levitation apparatus (EML).

Due to strong magnetic field forces that must counteract gravity in ground based EML experiments, the liquid sample droplet gets deformed. While it is possible to make corrections in the data analysis, the optimal way to deal with gravity is to escape it. The international space station (ISS) hosts an electromagnetic levitation apparatus where experiments can be performed under microgravity conditions. However, in order to have samples analyzed in space, one must make sure to know the experimental parameters and be positive about a successful experimental outcome. Therefore, samples that are prospects for experiments in space have to be tested under microgravity in a cheaper way – on board of parabolic flights. Together with DLR the industrial steel L331 by Böhler Special Steels will be analyzed on parabolic flights and these results will be compared with those obtained in ground-based experiments.

Additionally, as a part of the EMPIR EURAMET project 17IND11 “Hi-TRACE” comparative measurements on standard materials were performed to establish new methods for characterizing the thermophysical properties of any solid material up to 3000 °C.