Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 12: Topical Session (Symposium MM): Fundamentals of Fracture

MM 12.5: Vortrag

Montag, 12. März 2018, 17:00–17:15, TC 006

In Situ TEM and SEM Fracture Experiments at RT — •Inas Issa and Daniel Kiener — Department Materials Physics, Montanuniversitat Leoben, Austria

Among high strength and elastic limit that materials gain when decreasing their volumes to the sub-micron range, they exhibit large plastic deformation under high load. Mechanisms proposed are mainly size, among other parameters, dependent. Fewer studies are dedicated on the investigation of the *intrinsic* size effect on the strengthening of materials, i.e. fracture experiments at RT in the nanoscale. A good knowledge of the critical size for materials strengthening and for BDT of brittle materials, allows better design guideline of more fracture resistant, tough materials and avoid brittle failure of semiconductors used in many advanced microelectronic devices. We present in situ TEM fracture experiments at RT on metallic and semiconductors single crystals nanobending beams of thickness ranging from [70-400] nm. Dislocations activities and characters at the notche zone are investigated. Size effect on notch blunting and increase of fracture toughness is observed. Notches are introduced in TEM and others using Fib. Thus, a comparative study on the notches size effect on fracture toughness measurements is performed. In situ SEM fracture tests on similar but larger metallic samples are performed and on ultrafine grains ones. Thus, the influence of interfaces on the crack propagations is also studied.