Nanoindentation of single crystalline Mo: Atomistic defect nucleation and thermomechanical stability

• DOI: 10.1016/j.msea.2021.141912
• Publication Date: 2021-08-28T18:18:45Z
• Authors: F.J. Domínguez-Gu...; S. Papanikolaou; A. Esfandiarpour; P. Sobkowicz; M. Alava
• Keywords: Molybdenum; Dislocation junctions; Condensed Matter - Materials Science; Dislocation dynamics; ta114; HT Nanoindentation; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Physics - Applied Physics; Applied Physics (physics.app-ph); 02 engineering and technology; Computational Physics (physics.comp-ph); 01 natural sciences; Thermomechanics; 0205 materials engineering; 0103 physical sciences; Plastic deformation; Physics - Computational Physics

The mechanical responses of single crystalline Body-Centered Cubic (BCC) metals, such as molybdenum (Mo), outperform other metals at high temperatures, so much that they are considered excellent candidates for applications under extreme conditions, the divertor fusion reactors. thermomechanical stability temperatures (400-1000$^{\rm o}$C) has also been detected through nanoindentation, pointing towards connections to emergent local dislocation mechanisms related defect nucleation. In this work, we carry out a computational study effects temperature on deformation properties Mo nanoindentation. Molecular dynamics (MD) simulations spherical nanoindentation performed two indenter tip diameters and sample orientations [100], [110], [111], range 10-1000K. We investigate how increase influences process, modifying densities, mechanisms, atomic displacements also, hardness, in agreement with reported experimental measurements. Our results suggest characteristic formation high-temperature [001] junctions during contrast BCC may be cause persistent Mo.