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Using combinatorial methodology to get a better understanding of the intermetallic precipitation strengthening
Never before has such an extensive investigation been conducted on all aspects of the Process-Structure-Property correlation triangle in modern Co-free maraging steels.
Laura Moli Sanchez
It takes 400 unique lab samples and systematic screening to identify the effect of individual alloying elements and heat treatment parameters on precipitation and strength.
Nele Van Steenberge
Every R&D project, regardless its complexity or size, starts in the workshop. Next to machining all samples according to specifications, traceability is key. Thanks to our unique LIMS, where we keep track of each individual sample location and origin, this traceability is guaranteed!
Koen Van Brussel
Combinatorial methodology has been used on the RFCS (Research Fund for Coal and Steel) funded project INiTiAl. The goal: to accelerate material processing and screening and to build up knowledge.
QUICKLY GENERATING LARGE SETS OF SAMPLES
The INiTiAl project targets the development and implementation of corrosion-resistant high-strength maraging steels for two applications (aerospace and industry), with two different strength levels, 1400 and 1900MPa. Macroscopically, this project aims to study the Process-Structure-Property (PSP) correlations of these novel highstrength maraging steels with Ni-Ti-Al based intermetallic nanoprecipitation. Within the RFCS funded INiTiAl project, OCAS is focusing its efforts on the development of lean maraging steels for stress corrosion cracking resistance. The additional advantages of maraging over regular high-strength carbon steels are enhanced weldability and design freedom, as shaping can be done before the strengthening ageing treatment is applied. To achieve these objectives, OCAS has used the combinatorial approach in a lab wave generating up to 400 materials.
Via the laboratory combinatorial processing in combination with extensive dilatometry, the project aims at understanding the isolated effect of single intermetallic phases (mainly Ni3Ti and NiAl) and other elements (e.g., Mo and Cr) and process parameters on strength and other properties (e.g., toughness and/or corrosion). The combinatorial approach is combined with high-resolution techniques such as high-resolution Transmission Electron Microscope (TEM), Atom Probe Tomography (APT) and high-resolution synchrotron X-ray diffraction (SyXRD). Those techniques are key to quantifying the effect of individual intermetallics on the properties and to calibrate precipitation kinetic models. OCAS’s combinatorial approach includes pilot scale facilities for casting, rolling and heat treatments, as well as a broad range of characterisation tools, for mechanical properties as well as for standard microstructural characterisation. Further combinatorial competences are being developed to speed up other properties and characterisation screenings.
