Twin boundary migration mechanisms in quasi-statically compressed and plate-impacted Mg single crystals.

Twinning is a prominent deformation mode that accommodates plasticity in many materials. This study elucidates the role of deformation rate on the atomic-scale mechanisms that govern twin boundary migration. Examination of Mg single crystals deformed under quasi-static compression was compared with crystals deformed via plate impact.

[Odontoid fracture after high impact trauma : Assess instability correctly].

Odontoid process fractures are frequent injuries of the cervical spine and usually occur at an advanced age and often due to minor trauma. In younger patients they are mainly observed in the context of high impact trauma. Odontoid fractures are classified according to Anderson and D'Alonzo.

Tuning the deformation mechanisms of boron carbide via silicon doping.

Boron carbide suffers from a loss of strength and toughness when subjected to high shear stresses due to amorphization. Here, we report that a small amount of Si doping (~1 atomic %) leads to a substantial decrease in stress-induced amorphization due to a noticeable change of the deformation mechanisms in boron carbide. In the undoped boron carbide, the Berkovich indentation-induced quasi-plasticity is dominated by amorphization and microcracking along the amorphous shear bands.

Nanotwinned metal MEMS films with unprecedented strength and stability.

Silicon-based microelectromechanical systems (MEMS) sensors have become ubiquitous in consumer-based products, but realization of an interconnected network of MEMS devices that allows components to be remotely monitored and controlled, a concept often described as the "Internet of Things," will require a suite of MEMS materials and properties that are not currently available. We report on the synthesis of metallic nickel-molybdenum-tungsten films with direct current sputter deposition, which results in fully dense crystallographically textured films that are filled with nanotwins. These films exhibit linear elastic mechanical behavior and tensile strengths exceeding 3 GPa, which is unprecedented for materials that are compatible with wafer-level device fabrication processes.