Multiscale modelling for fusion and fission materials: the M4F project

The M4F project brings together the fusion and fission materials communities working on the prediction of radiation damage production and evolution and its effects on the mechanical behaviour of irradiated ferritic/martensitic (F/M) steels. It is a multidisciplinary project in which several different experimental and computational materials science tools are integrated to understand and model the complex phenomena associated with the formation and evolution of irradiation induced defects and their effects on the macroscopic behaviour of the target materials. In particular the project focuses on two specific aspects: (1) To develop physical understanding and predictive models of the origin and consequences of localised deformation under irradiation in F/M steels; (2) To develop good practices and possibly advance towards the definition of protocols for the use of ion irradiation as a tool to evaluate radiation effects on materials. Nineteen modelling codes across different scales are being used and developed and an experimental validation programme based on the examination of materials irradiated with neutrons and ions is being carried out. The project enters now its 4th year and is close to delivering high-quality results. This paper overviews the work performed so far within the project, highlighting its impact for fission and fusion materials science.This work has received funding from the Euratom research and training programme 2014-2018 under grant agreement No. 755039 (M4F project)

Robustness of Adamussium colbecki shell to ocean acidification in a short-term exposure

Atmospheric pCO2 has increased since the industrial revolution leading to a lowering of the ocean surface water pH, a phenomenon called ocean acidification (OA). OA is claimed to be a major threat for marine organisms and ecosystems and, particularly, for Polar regions. We explored the impact of OA on the shell mechanical properties of the Antarctic scallop Adamussium colbecki exposed for one month to acidified (pH 7.6) and natural conditions (unmanipulated littoral water), by performing Scanning Electron Microscopy, nanoindentation and Vickers indentation on the scallop shell. No effect of pH could be detected either in crystal deposition or in the mechanical properties. A. colbecki shell was found to be resistant to OA, which suggests this species to be able to face a climate change scenario that may threat the persistence of the endemic Antarctic species. Further investigation should be carried out in order to elucidate the destiny of this key species in light of global change

Mechanical and tribological properties of WO2.9 and ZrO2 + WO2.9 composites studied by nanoindentation and reciprocating wear tests

Funding Information: This work was supported partially within the framework of the SINTERCER project (REGPOT-2012-2013-1 EUFP7, project no. 316232 ) by the European Commission under the FP7 Specific Programme ‘Capacities’), and by Academy of Finland via Graduate School for Advanced Materials and Processes (Grant 118728 ). Dr. Ajai Iyer is acknowledged for his help in Raman measurements and Mr. Andreas Friman for his help with tribology tests. Mr. Joonas Lehtonen is acknowledged for helpful discussions. Publisher Copyright: © 2021 The Authors Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Oxygen vacancies in WO2.9 yield to formation of easy shear planes and they can potentially be applied in boundary lubrication conditions for reducing friction. Mechanical and tribological properties of pulsed electric current sintered monolithic WO2.9 were studied by nanoindentation and nanoscratch, and the composites of ZrO2 + WO2.9 with reciprocating wear tests. Hardness of WO2.9 at 25 °C was ~11 GPa and reduced elastic modulus was ~150 GPa. The ploughing dominated coefficient of friction as between 0.09 and 0.24 when measured against a Berkovich diamond tip. The composite n-ZrO2 + 10 vol% WO2.9 presented the lowest CoF, and wear rate 10−10 mm3/Nm measured under 10 N load against alumina ball (6 mm diameter) due to WO2.9 acting as a solid lubricant.Peer reviewe