Strength differences arising from homogeneous versus heterogeneous dislocation nucleation

From “Smaller is Stronger” to “Size‐Independent Strength Plateau”: Towards Measuring the Ideal Strength of Iron

“…When materials are subjected to external applied stresses, edges, corners, notches and surface roughness on free surfaces or even atomic-level surface steps can serve as dislocation nucleation sites, at a stress level significantly less than the ideal strength [18][19][20][21].…”

Incipient plasticity of single-crystal tantalum as a function of temperature and orientation

“…Compared to face centered cubic (FCC) systems, where the correlation between incipient plasticity and dislocation motion has been well established [5,6,8,[14][15][16][17][18][20][21][22]. BCC systems are much more complex and, despite several reports [11][12][13][23][24][25][26][27][28][29], there are still many unanswered questions regarding our understanding of BCC-plasticity in nanocontacts encountered in indentation.…”

“…The strength of this technique lies in its ability to probe ultra-small and therefore virtually "defect-free" sample volumes. In well-prepared surfaces of single crystals, this leads to the appearance of discontinuities in the loaddisplacement curves that are generally explained by homogeneous nucleation of dislocations loops in the area of maximum stress underneath the indenter [14][15][16][17][18].…”

Ideal shear strength of γ-Ni3Al and β-NiAl alloys

“…Однако с появлением таких экспе-риментальных методик, как наноиндентирование [1,2] и выращивание монокристаллических наностолбиков [3], стало возможным испытывать на прочность чрезвы-чайно малые объемы вещества, в которых количество дефектов настолько мало, что они могут считаться без-дефектными. В результате такие материалы демонстри-руют прочность, близкую к теоретической.…”