Design of transformation-induced plasticity-assisted dual-phase high-entropy alloys
In this project, we employ a metastability-engineering strategy to design bulk high-entropy alloys (HEAs) with multiple compositionally equivalent high-entropy phases.
HEAs are originally proposed to benefit from phase-stabilization through entropy-maximization. Yet, the concept is overturned in this project by designing a massive solid solution strengthened, transformation-induced plasticity-assisted, dual-phase HEA (TRIP-DP-HEA). We decrease phase stability to achieve two key benefits: (i) interface hardening due to a dual-phase microstructure (that results from reduced thermal-stability of the high temperature phase); (ii) transformation-induced hardening (that results from the reduced mechanical-stability of the room temperature phase). This combines the best of two worlds: extensive hardening of advanced steels owing to decreased phase stability, and massive solid solution strengthening of HEAs.
Within the EU project „ADVANCE - Sophisticated experiments and optimisation to advance an existing CALPHAD database for next generation TiAl alloys”, MPIE collaborated with Thermocalc-Software AB, Stockholm, Montanuniversität Leoben and Helmholtz-Zentrum Hereon, Geesthacht. At MPIE the focus lay on the production and heat treatments of model alloys…
The promising mechanical properties of metallic glasses (MG) such as high hardness, yield strength, and toughness [1] are desirable to exploit for structural applications. Monolithic MGs lack grains and grain boundaries; thus, the mechanical properties of MGs are depending on the chemistry as well as processing and testing conditions. However…
Scandium-containing aluminium alloys are currently attracting interest as candidates for high-performance aerospace structural materials due to their outstanding combination of strength, ductility and corrosion resistance. Strengthening is achieved by precipitation of Al3Sc-particles upon ageing heat treatment.
In this project, we aim to synthetize novel ZrCu thin film metallic glasses (TFMGs) with controlled composition and nanostructure, investigating the relationship with the mechanical behavior and focusing on the nanometre scale deformation mechanisms. Moreover, we aim to study the mechanical properties of films with complex architectures such as…
Wear-related energy loss and component damage, including friction and remanufacturing of components that failed by surface contacts, has an incredible cost. While high-strength materials generally have low wear rates, homogeneous deformation behaviour and the accommodation of plastic strain without cracking or localised brittle fracture are also…
Multiple Exciton Generation (MEG) is a promising pathway towards surpassing the Shockley-Queisser limit in solar energy conversion efficiency, where an incoming photon creates a high energy exciton, which then decays into multiple excitons.
In this project, we aim to design novel NiCoCr-based medium entropy alloys (MEAs) and further enhance their mechanical properties by tuning the multiscale heterogeneous composite structures. This is being achieved by alloying of varying elements in the NiCoCr matrix and appropriate thermal-mechanical processing.
The exploration of high dimensional composition alloy spaces, where five or more alloying elements are added at near equal concentration, triggered the development of so-called high entropy (HEAs) or compositionally complex alloys (CCAs). This new design approach opened vast phase and composition spaces for the design of new materials with advanced…