We present a novel experimental method for quantitatively characterizing the temperature-dependent mechanical behavior of individual nanostructures during uniaxial straining. By combining a microelectromechanical tensile testing device with a low thermal mass and digital image correlation providing nm-level displacement resolution, we show successful incorporation of a testing platform in a vac...

The present study was performed on A356 and B319 alloys in mechanically stirred or degassed condition. Melts were Sr-modified grain-refined. Hydrogen content varied from less than 0.1 ml/100 g Al to ∼0.4 Al; Fe increased 0.8% alloy. Lanthanum cerium added as 99.5% pure metals. Two main techniques used investigate porosity formation: fracture surface of tensile fatigue test bars, reduced pressur...

The deformation of metallic glasses involves two competing processes: a disordering process involving dilatation, free volume accumulation, and softening, and a relaxation process involving diffusional ordering and densification. For metallic glasses at room temperature and under uniaxial loading, disordering usually dominates, and the glass can fail catastrophically as the softening process ru...

Fatigue pre-cracked four-point bend specimens of a rolled AZ31 Mg alloy are loaded asymmetrically and their mixed-mode (I II) fracture behaviour is contrasted with pre-notched samples. In-situ mapping displacement strain fields performed through optical imaging coupled digital image correlation analysis. The surface morphology the deformed microstructure also studied. toughness Jc for both type...

Pressurized water reactor (PWR) cores operate under extreme environmental conditions due to coolant chemistry, operating temperature, and neutron exposure. Extending the life of PWRs requires detailed knowledge of the changes in mechanical and corrosion properties of the structural austenitic stainless steel components adjacent to the fuel (internals) that are inherent to such conditions. This ...

An impact fatigue study has been made for the first time on 63⋅5% glass fibre reinforced vinylester resin notched composites. The study was conducted in a pendulum type repeated impact apparatus especially designed and fabricated for determining single and repeated impact strengths. A well-defined impact fatigue (S–N) behaviour, having a progressive endurance below the threshold single cycle im...

Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories, California (SNL) are collaborating on the development of new techniques to study damage evolution and growth in material specimens subjected to mechanical loading. These techniques include metallography, radiography, computed tomography (CT) and modeling. The material specimens being studied include cast magnesium a...