Neutrons for Advancing High‑Temperature Superalloys

by Steffen Neumeier (Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg)

Monday 20 Apr 2026, 14:30 → 15:30 Europe/Berlin

PH HS 3 (Physics Department)

Modern technologies such as aviation, energy conversion in gas turbines, solar towers or fusion reactors, aerospace and communication rely critically on high‑temperature structural materials. Among them, Ni‑based superalloys are key materials of our society: they combine exceptional mechanical strength at high homologous temperatures with remarkable oxidation and corrosion resistance. To increase engine efficiency and enable future hydrogen‑based energy systems, new superalloys with enhanced high‑temperature capability and well‑understood hydrogen effects are needed. Their development and characterization are demanding, since superalloys contain more than ten alloying elements, exhibit a complex hierarchical microstructure across multiple length scales, and even the site occupancy of the alloying element in the crystal lattice strongly influences their properties. Moreover, their microstructure and mechanical behaviour evolve significantly with temperature, requiring in‑situ characterization techniques.

Neutrons are uniquely suited to investigate such structural materials due to their deep penetration, excellent sensitivity to light elements, and suitability for in‑situ studies under extreme environments.

In this presentation, complementary neutron diffraction and small‑angle neutron scattering results on new Ni‑ and Co‑based superalloys will be shown. Temperature‑dependent lattice misfit measurements between the main phases explain the observed precipitate morphologies and provide input for calculating interfacial dislocation force balances. Small‑angle scattering results allow optimisation of heat treatment routes to enhance mechanical performance. Furthermore, neutron investigations of hydrogen–lattice interactions reveal hydrogen partitioning behaviour and help elucidate mechanisms of hydrogen embrittlement.

These insights demonstrate how neutron techniques contribute to designing more robust and efficient superalloys for demanding high‑temperature applications.