Project Details
Projekt
Pressure-assisted thermochemical treatment of high-performance alloys (T14*)
Subject Area
Metallurgical, Thermal and Thermomechanical Treatment of Materials
Term
since 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 190389738
Integrated heat treatments with hot isostatic press (HIP) for single crystal (SX) Ni-based superalloys were developed as part of the CRC/TR 103. The necessary solution heat treatment was integrated into the HIP treatment to improve the mechanical properties by closing the remaining pores. The combination of these two processes is only feasible due to the possibility of quenching within the HIP system, whereby the high-temperature state of the material can be frozen. Chemical interactions between the process gas and the heat-treated material were specifically avoided by using Ar. The aim of this transfer project is to introduce nitrogen into high-performance materials by hot isostatic pressing in a reactive gas atmosphere. The high pressures and temperatures during HIP heat treatment facilitate the introduction of nitrogen and close the porosity in the material. This should make it possible to introduce nitrogen into materials with low nitrogen solubility at atmospheric pressure and to create defined nitrogen profiles in these materials. For this purpose, HIP heat treatments with variations in pressure, nitrogen partial pressure (process gas mixtures), temperature and dwell time are planned. The choice of parameters is influenced by thermodynamic calculations using Thermo Calc® software. The tests are carried out on two model alloys. These are a polycrystalline Ni-based superalloy (IN718, EN 2.4668) and an austenitic stainless steel (X2CrNiMo17-12-2, EN 1.4404). Both are processed in both conventional and additive manufacturing. HIP-integrated thermochemical treatment is likely to be of high technological relevance for additively manufactured materials in particular, as the very high temperature of the melt bath prevents a significant nitrogen content. All in all, this transfer project aims to develop a novel and unrivalled thermochemical high-pressure heat treatment in a HIP. Together with Quintus, the project seeks to explore the potential and limitations of this new manufacturing technology.
DFG Programme
CRC/Transregios (Transfer Project)
Subproject of
TRR 103:
From Atoms to Turbine Blades - A Scientific Approach for Developing the Next Generation of Single Crystal Superalloys
International Connection
Sweden
Applicant Institution
Ruhr-Universität Bochum
Business and Industry
Quintus Technologies AB
