This article presents a study on elastic anisotropy of Cu by indentations at different penetration depth ranges (sub-10 nm, several-10 nm, and several-100 nm), and the impact of elastic anisotropy on ...the stress in 3D stacked integrated circuits (3D ICs). The reduced modulus, ER, values determined at sub-10 nm indentations on Cu single crystals are very close to the unidirectional values. Similarly, cross-sectional sub-10 nm indentation tests on the Cu grains in a through-silicon via (TSV) show unidirectional ER values. In contrast, the Hill’s average values are observed at several-100 nm indentations. We propose that before lattice rotation happens within a volume beneath the indentation, elastic anisotropy can be strongly reflected in the ER value. When the experimentally measured Cu elastic anisotropy is used in a technology computer-aided design simulation of a Cu-filled TSV, significant impacts are observed on the stress field and the carrier mobility variation in an active Si region.
The hardness of deformation-induced α'- martensite and parent austenitic matrix in high-alloy CrMnNi steel was investigated by nanoindentation measurements inside scanning electron microscope using ...picoindenter. After the indentation, the microstructure was investigated by electron backscattered diffraction measurements. The hardness values for α'-martensite are only 24% higher than those of austenite. Thus, the increase in strength during the formation of deformation-induced α'-martensite is rather caused by the small grain size of α'-nuclei resulting in a dynamic Hall-Petch effect than by its "intrinsic" hardness.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We use in-situ heated nanoindentation to investigate the high-temperature nanomechanical properties of epitaxial and textured ZrB2 films deposited by magnetron sputtering. Epitaxial films deposited ...on 4H-SiC(0001) show a hardness decrease from 47GPa at room temperature to 33GPa at 600°C, while the reduced elastic modulus does not change significantly. High resolution electron microscopy (HRTEM) with selected area electron diffraction of the indented area in a 0001-textured film reveals a retained continuous ZrB2 film and no sign of crystalline phase transformation, despite massive deformation of the Si substrate. HRTEM analysis supports the high elastic recovery of 96% in the films.
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The properties of a resin transfer molded sheet of strand-reinforced composite for automotive applications are investigated at the microscopic level. Three components of the composite can be ...identified in the bright field micrograph – glass fibers, epoxy matrix and binder. The latter having been added in manufacturing process. Accelerated Nanoindentation with 64.451 single indentation experiments is performed at room temperature to generate a mechanical property map of an area containing the 3 components. The distribution of properties, mean value and standard deviation, is determined for each component. Two locations in the composite are selected for a study of the local glass transition behavior by performing dynamic indentation experiments while simultaneous variation of the temperature of the indenter tip and sample within a micro-heating chamber.
Nanoindentation is an ideal technique to study local mechanical properties of a wide range of materials on the sub-micron scale. It has been widely used to investigate biological materials in the dry ...state; however, their properties are strongly affected by their moisture content, which until now has not been consistently controlled. In the present study, we developed an experimental set-up for measuring local mechanical properties of materials by nanoindentation in a controlled environment of relative humidity (RH) and temperature. The significance of this new approach in studying biological materials was demonstrated for the secondary cell wall layer (S2) in Spruce wood (Picea abies). The hardness of the cell wall layer decreased from an average of approximately 0.6 GPa at 6% RH down to approximately 0.2 GPa at 79% RH, corresponding to a reduction by a factor of 3. Under the same conditions, the indentation modulus also decreased by about 40%. The newly designed experimental set-up has a strong potential for a variety of applications involving the temperature- and humidity-dependent properties of biological and artificial organic nanocomposites.
Organic semiconducting polymers have attractive electronic, optical, and mechanical properties that make them materials of choice for large area flexible electronic devices. In these devices, the ...electronically active polymer components are micrometers in size, and sport negligible performance degradation upon bending the centimeter‐scale flexible substrate onto which they are integrated. A closer look at the mechanical properties of the polymers, on the grain‐scale and smaller, is not necessary in large area electronic applications. In emerging micromechanical and electromechanical applications where the organic polymer elements are flexed on length scales spanning their own micron‐sized active areas, it becomes important to characterize the uniformity of their mechanical properties on the nanoscale. In this work, the authors use two precision nanomechanical characterization techniques, namely, atomic force microscope based PeakForce quantitative nanomechanical mapping (PF‐QNM) and nanoindentation‐based dynamical mechanical analysis (nano‐DMA), to compare the modulus and the viscoelastic properties of organic polymers used routinely in organic electronics. They quantitatively demonstrate that the semiconducting near‐amorphous organic polymer indacenodithiophene‐co‐benzothiadiazole (C16‐IDTBT) has a higher carrier mobility, lower modulus, and greater nanoscale modulus areal uniformity compared to the semiconducting semicrystalline organic polymer poly2,5‐bis(3‐tetradecylthiophen‐2‐yl)thieno3,2‐bthiophene (C14‐PBTTT). Modulus homogeneity appears intrinsic to C16‐IDTBT but can be improved in C14‐PBTTT upon chemical doping.
Nanomechanical devices built from organic semiconductors require a deeper understanding of the mechanical properties on the scale of an individual polymer grain. In this report, the surface nanomechanical texture of high mobility polymers traditionally used for organic electronics is quantified together with their depth dependent viscoelastic response.
A single hydride platelet and the matrix material next to it in a Zircaloy-2 cladding have been targeted for hardness, H, and Young’s modulus, E, measurement using nanoindentation. The results were ...compared with those obtained in the matrix material far away from the hydride.
The results show that hardness and Young’s modulus in the hydride are higher than those of the matrix adjacent to the hydride, which are the same as those of the matrix far away from the hydride.
It is well known that materials of same indentation hardness do not necessarily exhibit the same wear behaviour. A nanomechanical test is required, to describe the behaviour more accurate. The Mohs ...minerals define a relative hardness scale by scratch testing samples. They are used as a reference. This set of standard minerals is tested by conventional quasistatic nano-indentation testing as well as by nanoscratch testing. The objective is to define whether the scratch resistance and wear behaviour of the minerals is better tested by indentation testing or rather by scratch testing.
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