Neutron embrittlement

Neutron embrittlement, sometimes more broadly radiation embrittlement, is the embrittlement of various materials due to the action of neutrons. This is primarily seen in nuclear reactors, where the release of high-energy neutrons causes the long-term degradation of the reactor materials. The embrittlement is caused by the microscopic movement of atoms that are hit by the neutrons; this same action also gives rise to neutron-induced swelling causing materials to grow in size, and the Wigner effect causing energy buildup in certain materials that can lead to sudden releases of energy.

Neutron embrittlement mechanisms include:

• Hardening and dislocation pinning due to nanometer features created by irradiation
• Generation of lattice defects in collision cascades via the high-energy recoil atoms produced in the process of neutron scattering.
• Diffusion of major defects, which leads to higher amounts of solute diffusion, as well as formation of nanoscale defect-solute cluster complexes, solute clusters, and distinct phases.^[1]