Bioinspired ceramics with micron-scale ceramic "bricks" bonded by a metallic "mortar" are projected to result in higher strength and toughness ceramics, but their processing is challenging as metals do not typically wet ceramics. To resolve this issue, we made alumina structures using rapid pressureless infiltration of zirconium-based bulk-metallic glass mortar that reactively wets the surface freeze-cast preforms. The mechanical properties resulting Al2O3 glass-forming compliant-phase...

To investigate the mechanism of {101¯2} twinning in magnesium (Mg) single crystal and its influence on mechanical size effects strain rate dependent deformation behavior, in-situ microcompression Mg [21¯1¯0] pillars various sizes from 0.5 μm to 4 was carried out a scanning electron microscope (SEM) also transmission (TEM), covering rates 10−4 10−2 s−1. The observations directly showed that pile-up prismatic <a> dislocations acts as local stress concentration for twin nucleation. Preceding...

Nanoindentation based techniques were significantly enhanced by continuous stiffness monitoring capabilities. In essence, this allowed to expand from point-wise discrete measurement of hardness and elastic modulus towards advanced plastic characterization routines, spanning the whole rate-dependent spectrum steady state creep properties via quasi static flow curves impact or brittle fracture. While representing a significant step forwards already, these can tremendously benefit additional...

Measuring the local behaviour of a propagating crack in quantitative manner has always been challenge field fracture mechanics. In-situ microcantilever testing inside scanning electron microscope (SEM) is one most promising techniques for investigation thereof. However, quantifying such experiments fairly challenging. Here, first time we utilize continuous measurement dynamic compliance in-situ to permit evaluation length. Microcantilever have performed on brittle single crystalline Si and...

The influence of microstructure on the strength scaling behaviour ultrafine-grained bcc metals is investigated by scale-bridging experiments spanning four orders length tungsten and chromium. By performing macroscopic compression experiments, nanoindentation in-situ micro-compression tests in a scanning electron microscope, plastically deformed volume was thoroughly reduced until transition from bulk to single crystalline deformation characteristics achieved. stress-strain local sample were...

Abstract The integrity of structural materials is oftentimes defined by their resistance against catastrophic failure through dissipative plastic processes at the crack tip, commonly quantified J -integral concept. However, to date experimental stress and strain fields necessary quantify associated with local propagation in its original integral form were inaccessible. Here, we present a multi-method nanoscale strain- stress-mapping surrounding growing tip two identical miniaturized fracture...

The inherent brittleness of the refractory metal tungsten represents a major challenge for its application as divertor material in future nuclear fusion reactors. Grain refinement to ultrafine-grained regime is promising strategy increase fracture toughness W, but it also promotes intercrystalline crack growth. Therefore, strengthening grain boundary cohesion W great importance. In this work, doping with B and Hf, two elements that were identified previous work bending strength ductility,...

Abstract Tungsten-copper composites are used in harsh environments because of their superior material properties. This work addresses a tungsten-copper composite made 20 wt.% copper, which was subjected to grain refinement by high-pressure torsion, whereby the deformation temperature varied between room and 400 °C tailor size. Deformation performed up microstructural saturation verified hardness measurement scanning electron microscopy. From refined nanostructured material, micro-cantilever...

Hard protective coating materials based on transition metal nitrides and carbides typically suffer from limited fracture tolerance. To further tune these properties non-metal alloying – substituting C with N has been proven favorable for magnetron sputtered Hf-C-N thin films. A theoretically predicted increase in valence electron concentration (from 8.0 to 9.0 e/f.u. HfC HfN) through nitrogen lead an toughness (KIC obtained during in-situ SEM cantilever bending) 1.89 ± 0.15 2.33 0.18...

The present work provides an analytic solution for the stiffness to crack length relation in microscopic cantilever shaped fracture specimens based on classical beam theory and substitution of by a virtual rotational spring element. resulting compact relationship allows accounting actual beamgeometry agrees very well with accompanying finite element simulations. Compared only other model literature proposed reduces deviation between data maximum 1.6% fromthe previous minimumof 15%. Thus,...

Abstract Intermetallic γ‐TiAl‐based alloys are commonly used as structural materials for components in high‐temperature applications, although they generally suffer from a lack of ductility and crack resistance at ambient temperatures. Within this study, the process‐adapted 4th generation TNM + alloy, exhibiting fully lamellar microstructure, was examined using notched micro‐cantilevers with defined orientations interfaces. These configurations were tested situ superimposed continuous...

Abstract Micro- and nanomechanical testing techniques have become an integral part of today’s materials research portfolio. Contrary to well-studied majorly standardized nanoindentation testing, in situ various geometries, such as pillar compression, dog bone tension, or cantilever bending, remains rather unique given differences experimental equipment sample processing route. The quantification experiments is oftentimes limited load-displacement data, while the gathered images are...

W-Cu composites are commonly used as heat-sinks or high-performance switches in power electronics. To enhance their mechanical properties and mutually usability, grain refinement of the initially coarse-grained microstructure was realized using high–pressure torsion. This leads to different microstructural conditions, exhibiting fine-, ultrafine-grained nanocrystalline microstructures. Scanning well transmission electron microscopy performed analyze respective size The hardness Young’s...

Two-photon lithography (TPL) enables the design of novel micromechanical specimens, down to sub-micron resolution, thus extending possibilities for device and material characterisation pushing boundaries a broad range miniaturized technologies such as optics, analytics, medicine. Employing push-to-pull geometry, incorporating double edge notched tension specimens loaded in mode I, specimen manufacturing testing can be automated large extent. This allows use parameter space methods essential...

Abstract With modern materials applications continually decreasing in size, e.g., microelectronics, sensors, actuators, and medical implants, quantifying parameters becomes increasingly challenging. Specifically, addressing individual constituents of a system, such as interfaces or buried layers multilayer structure, emerges topic great importance. We demonstrate herein technique to assess fracture different Cu-WTi-SiO x -Si model system based on situ microcantilever testing scanning...

With a considerable amount of commonly used material systems consisting individual, rather confined layers, the question for mechanical behaviour their individual interfaces arises. Especially, when considering varying interfacial structures as result processing environment. Furthermore, interaction between pronounced plasticity and fracture processes can lead to challenges with regards separation sole interface- or bulk properties. The present work investigates characteristic WTi-Cu sytem...

Abstract The ongoing trend towards miniaturization in various fields of material science requires the capability to investigate local mechanical properties concerned structures by miniaturized experiments. Besides nanoindentation, experiments such as micro-compression, micro-tension, micro-bending, or micro-fracture tests were employed frequently recent times. A major challenge for these is fabrication specimens. Therefore, we present different approaches prepare testing objects a site...

Abstract Nanostructured materials with their remarkable properties are key enablers in many modern applications. For example, industrial dry-milling processes would not be as widely spread without the use of hard, wear-resistant metal nitride coatings to protect cutting tools. However, improving these nanostructured thin films regard dynamical is demanding probing respective parameters (sub-)micron layers any substrate influence still challenging. To extend scientific toolbox for such...

The technical potential of WCu alloys is limited by the modest fracture characteristics material system in its coarse-grained condition. To provide a nanocrystalline microstructure and improve mechanical properties, W-50 at.% Cu composite was processed using high-pressure torsion deformation at temperature 200 °C. Therefore, two specimens were subjected to 100% 1000% shear strains, respectively. Scanning electron scanning transmission microscopy, including nanoscale energy dispersive X-ray...

The study of grain boundaries (GBs) in polycrystalline materials is a field major interest, as many fundamental properties are influenced by their actual structure. One the main challenges investigating GBs that electron microscopy techniques capable to resolve atomistic arrangement require very small sample volumes few tens nanometers and might therefore change natural state GB via removal occurring material constraint. To counteract this influence one could apply indirect measurements such...

Micromechanical testing techniques can reveal a variety of characteristics in materials that are otherwise impossible to address. However, unlike macroscopic testing, these miniaturized experiments more challenging realize and analyze, as loading boundary conditions often not be controlled the same extent standardized tests. Hence, exploiting all possible information from such an experiment seems utmost desirable. In present work, we utilize dynamic in-situ microtensile nanocrystalline...