Thermal Desorption Spectrometer with MS

• Subject Area: Materials Science
• Term: Funded in 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 508420290

Hydrogen embrittlement of high-strength steels has been a known challenge for component design and fatigue strength of systems for more than 150 years. There are numerous examples of how hydrogen embrittlement has led to enormous damage and thus to high costs. As hydrogen will become more and more present in technical systems in the coming years due to the energy transition and a resource-efficient use of materials requires increasingly high-performance materials, the issue of hydrogen embrittlement will become essential. Particularly in the case of metallic materials, strength-increasing and thus more sustainable alloying concepts are making the materials increasingly susceptible to hydrogen degradation. The instrument is a multi-analyzer system for the determination of hydrogen (H), oxygen (O), nitrogen (N) and argon (Ar) concentrations especially in metallic samples. Concentrations down to the sub-ppm range can be resolved. In carrier gas melt extraction, samples weighing a few grams (depending on density) are melted in a temperature-controlled manner at temperatures up to 3500°C and the contents of the gases to be analyzed (O,N,H,Ar) released from the material sample into the carrier gas stream are determined. At the same time, hot carrier gas extraction can be carried out by means of an auxiliary infrared furnace at temperatures up to 1100°C. Compared to melt extraction, a significantly larger sample can be subjected to both a stepped and a continuous temperature profile with the aim of improving the measurement resolution. The gas concentration released as a function of temperature can then be used to infer the trapping energy of the gas to be analyzed or of the gas atoms in the metal lattice, the energy with which hydrogen is localized at lattice defects and which a hydrogen atom must overcome to leave the defect. This method is also known as "Thermal Desorption Spectroscopy" (TDS). When the TDS system is combined with a quadrupole mass spectrometer (MS) due to the highest measurement resolution required for diffusible hydrogen (dH) detection, the method is referred to as TDMS. TDMS is mandatory to measure the trapping energies of hydrogen at lattice defects in the metal atom lattice in a defect-specific manner. Neither TDS, TDMS or hot/melt extraction are accessible despite years of intensive hydrogen research at Saarland University (UdS) or in the scientific and industrial environment.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Thermisches Desorptions-Spektroskop mit Massenspektrometer
• Instrumentation Group: 1520 Meßgeräte für Gase (O2, CO2)
• Applicant Institution: Universität des Saarlandes
• Leader: Professor Dr. Christian Motz