Materials Science and Engineering Commons^™

Measuring The Fracture Toughness Of Titanium Carbide Reinforcements At The Micronscale, Lionel Michelet, Martin Mueller, Vaclav Pejchal, Goran Zagar, Andreas Mortensen

Nanomechanical Testing in Materials Research and Development V

It is known that the mechanical properties of composite materials and alloys are strongly influenced by the intrinsic mechanical properties of their reinforcements or second phases. Such local properties are difficult to measure in particulate reinforcements or second phases because of the irregular shape and small size of material samples to be tested. We compare three methods that measure the fracture toughness of TiC reinforcements by combining focused ion beam (FIB) milling methods with nanoindentation techniques and finite element simulation. In-situ created TiC particles in a steel matrix are tested. Such particles are analysed by EBSD to select the crystalline …

A New Dynamic Module For In-Situ Nanomechanical Testing At High Strain Rate, Gaylord Guillonneau, J. Wehrs, G. Mohanty, D. Frey, S. Grop, J. Milchler, J.M. Breguet, Q. Longchamp, J.M. Wheeler

Nanomechanical Testing in Materials Research and Development V

In-situ nanomechanical testing is commonly used to probe surface mechanical properties of bulk materials or thin films, like hardness, Young’s modulus, Yield stress…Actually most of the instruments can measure these properties only statically, i.e. a low frequency, leading to property measurement only at low strain rate (usually 10^-1s^-1 by nanoindentation). This is mainly caused by the low resonance frequency of the system, preventing making tests at higher speed. Performing high dynamic measurements could bring new information on materials properties like deformation mechanism at high strain rate, or high dynamic fatigue properties.

A new high dynamic module usable …

Dislocation Dipoles And The Nucleation Of Cracks In Silicon Nanopillars, J. Rabier, F. Abed El Nabi, J. Godet, S. Brochard, L. Pizzagalli

Nanomechanical Testing in Materials Research and Development V

To understand the brittle to ductile transtion at small scale in silicon nanopillars, plastic deformation of silicon nanopillars was investigated by atomistic simulations. Perfect dislocations were found to be nucleated from surfaces and nano cavities were evidenced resulting from dislocation dipoles annihilation. The formation of such cavities is consistent with previous atomistic calculations showing that the annihilation of dislocation vacancy dipole of perfect shuffle dislocations is associated to the formation of vacancy clusters in silicon and diamond [1]. In nanopillars such cavities contribute to the nucleation of cracks [2]. This mechanism of crack nucleation is relevant to single slip deformation …

Development And Application Of An In-Situ Nanoindenter Coupled With Electrical Measurements, Solene Comby, Fabien Volpi, Florence Robaut, Rachel Martin, Francine Roussel, Frederic Roussel, Didier Pellerin, Marc Verdier

Nanomechanical Testing in Materials Research and Development V

The increasing demand for multifunctionality has become a recurring challenge for a wide panel of application fields such as microelectronics, microsystems, energy harvesting or structural applications.

This generally implies a smart combination of materials with tailored geometries, thus leading to ever more complex structures. The complexity of these new materials requires the development of higher performance characterization tools.

In that purpose, a multifunctional characterization set-up is developed in SIMaP laboratory, mainly based on electrical and mechanical coupling. This set-up is tailored for advanced measurements at the micrometer scale of structural and functional materials displaying small scale microstructure such as multiphase, …

A Direct Comparison Of High Temperature Nanoindentation And Tensile Creep Measurements For Aluminum, Warren Oliver, Richard Anthony, Sudharshan Pardhasaradhi

Nanomechanical Testing in Materials Research and Development V

Scanning electron microscope (SEM) in situ high temperature nanomechanical testing has received a lot of interest in recent times. Performing nanomechanical tests in non-ambient conditions presents several challenges. To meet those challenges a thorough understanding of the instruments’ performance both from static as well as dynamic point of view is required. In this regard, data from dynamic nanoindentation testing at temperatures up to 550 C on commercial purity aluminum in the SEM will be presented. The activation energy for creep was found to be 140 KJ/mol/K, matching the value determined with high temperature tensile creep experiments extremely well. The stress …

Micromechanical Behavior Of Thermal Barrier Coatings After Isothermal Oxidation, Carlos Serna, Deiby Maya, Alejandro Toro, Juan Meza

Nanomechanical Testing in Materials Research and Development V

Thermal protection of metallic components by using ceramic coatings like thermal barrier coatings (TBCs) is widely used, in rocket engines, aircraft industry and gas turbines for power generation to reduce the substrate temperature up to 165°C. This technology diminishes the heat transfer in combustor, initial rotor blades and nozzles guide vanes, so that turbines have taken special advantage of these coatings to meet increasing demands for greater fuel efficiency, lower NOx emissions and higher power and thrust [1]. Thermal barrier coatings, apart from thermal protection are also used to protect against abrasion, oxidation and corrosion [2].

The understanding of the …

Influence Of Temperature On The Deformation Behavior Of Single-And Bi-Crystal Microbending Beams, Jorge Velayarce, Mohammad Zamanzade, Oscar Torrents, Christian Motz

Nanomechanical Testing in Materials Research and Development V

The mechanical behavior of micron-scale structures varies drastically from their macro-scale counterparts. This phenomenon is known as size effect and has been extensively investigated for several decades. The understanding of the influence of temperature on the mechanical properties of components of electronic devices with micron or even sub-micrometer dimensions is essential for a reliable design. Hence micro-compression and micro-tension experiments on pure single-crystalline and polycrystalline face-centered cubic (fcc) metals have been carried out at different temperatures. However, in real microstructures complex stress and strain gradients arise from incompatibilities in elastic and plastic deformation, which are not addressed in tension or …

Chemomechanical Effects In Thin Film And Bulk Oxides, Steve Bull, Noushin Moharrani

Nanomechanical Testing in Materials Research and Development V

The environmental sensitivity of the surface mechanical properties of ceramics has long been known and properties such as plasticity, creep, fracture and fatigue have been shown to be susceptible to changes in the environment. These effects are often called Rehbinder effects after his pioneering work in the 1930s. Most relevant to indentation testing is “anomalous indentation creep” which has been observed by many workers in ceramics using both conventional microhardness and nanoindentation testing. Whereas a constant, time-independent hardness was found in microhardness measurements by testing in dry toluene the hardness was found to drop as the indentation time increased when …

Deformation Behavior Of Bulk Metallic Glasses Produced Via Severe Plastic Deformation And The Influence Of A Second Phase, Lisa Kraemer, Verena Maier, Karoline Kormout, Marlene Kapp, Yannick Champion, Reinhard Pippan

Nanomechanical Testing in Materials Research and Development V

Over the last years bulk metallic glasses (BMG) have been strongly investigated as their mechanical properties are very promising especially in terms of their high yield strength and high elastic strain. However, a major drawback is their complicated production depending strongly on dimensions and chemistry. A promising technique to overcome these drawbacks is using a severe plastic deformation process, e.g. high pressure torsion (HPT), where the production can be started with metallic glass powders, which are generally much easier to fabricate.

For this route, the powder is consolidated and then the powder particles are welded together by applying a high …

Mechanical Response Of Face-Centered Cubic Metallic Nanospheres Under Uniaxial Compression, Selim Haj Salah, Celine Gerard, Laurent Pizzagalli

Nanomechanical Testing in Materials Research and Development V

The mechanical response of metallic nanoparticles has recently attracted a lot of interest due to their specific properties compared to their bulk counterpart, which allow for novel applications in various fields, e.g., composite materials, nanomanufacturing/nano-electromechanical systems. We have employed Molecular Dynamic simulations to study the mechanical behavior of face-centered cubic metallic nanoparticles. Uniaxial compression of monocrystalline nanosphere is investigated using the EAM potentials developed by Mishin et al. [1] [2]. The resulting behaviors vary with nanoparticle size, crystallographic orientation, and temperature. This work shows that the elastic modulus of metallic nanoparticles is higher than that of the bulk material. Three …

Measuring Surface Dislocation Nucleation In Defect-Scarce Nanostructures, Daniel Gianola, Lisa Chen, Jungho Shin, Mo-Rigen He, Gunther Richter

Nanomechanical Testing in Materials Research and Development V

Linear defects in crystalline materials, known as dislocations, are central to the understanding of plastic deformation and mechanical strength, as well as control of performance in a variety of electronic and photonic materials. Despite a thorough understanding of dislocation structure and their interactions, measurements of the energetics and kinetics of dislocation nucleation have not been possible, as synthesizing and testing pristine crystals absent of defects has been prohibitively challenging. In this talk, experiments that directly measure the surface dislocation nucleation strengths in high qualityPd nanowhiskers subjected to uniaxial tension will be presented. We find that, whereas nucleation strengths are weakly …

Fracture Behavior Of High Strength Pearlitic Steel Wires, Bernhard Voelker, Anton Hohenwarter, Reinhard Pippan

Nanomechanical Testing in Materials Research and Development V

Steel wires are widely used in various industrial applications. Hence, the drawing process and the resulting mechanical properties are of significant scientific and industrial importance. In this investigation the focus is on pearlitic steel wires with relatively high drawing strains and resulting high ultimate tensile strengths up to several GPa.

The fracture behavior was investigated for two different wires with a drawing strain of 3.10 and 6.52 with a diameter of about 100 µm and 20 µm, respectively. The resulting ultimate tensile strength varies between 4 and 7 GPa [1]. The fracture toughness was measured with crack propagation direction in …

Quantification Of Mechanical Properties Gradient By Nano-Indentation And Microcompression Testing On Mechanically-Induced Transformed Surfaces, David Tumbajoy, Guillaume Kermouche, Sylvie Descartes, Jean Michel Bergheau, Gaylord Guillonneau, Johann Michler

Nanomechanical Testing in Materials Research and Development V

In the industry, there are several techniques which improve the service lifetime of materials by increasing the local mechanical properties in the near-surface. In the case of mechanical surface treatments (such as impact-based), the material is exposed to repeated mechanical loadings, producing a severe plastic deformation in the surface, and then leading to a local refinement of the microstructure into the affected zone (Tribologically Transformed Surfaces - TTS). The microstructure’s transformation is characterized by a progressive increment of the grain size from the surface until the bulk material. Consequently, very interesting physical properties such as high hardness and better tribological …

Ultra Small Scale High Cycle Fatigue Testing By Micro-Cantilevers, Jicheng Gong, Angus Wilkinson

Nanomechanical Testing in Materials Research and Development V

A new method has been developed for testing high cycle and very high cycle fatigue properties of materials at the micro-scale based on micro-cantilevers. Focused ion beam was employed to cut micro-cantilevers on the surface of a selected grain in a bulk polycrystalline commercial pure Titanium. The bulk specimen was pre-examined by EBSD, so the crystal orientation of all micro-cantilevers were known. The bulk sample with prepared micro-cantilevers was then attached to a high power ultrasonic generator, which can generate mechanical vibration at the frequency 20KHz. The bulk specimen moves with the ultrasonic generator, but the micro-cantilever lags somewhat behind. …

Comparison Of In Situ Micromechanical Time Dependent Plasticity Techniques: Micropillar Compression, Nanoindentation And Micro-Tensile Tests, Juri Wehrs, Gaurav Mohanty, Gaylord Guilloneau, Aidan Taylor, Brad Boyce, Jeffrey Wheeler

Nanomechanical Testing in Materials Research and Development V

Nanocrystalline metals exhibit strongly time-dependent plastic deformation. This results in a high degree of strain-rate sensitivity and susceptibility to creep and relaxation, even at room temperature. With the advent of thin film processing techniques like sputtering and electrodeposition for fabrication of controlled microstructures of nanocrystalline materials, nanoindentation and microcompression techniques are increasingly used to extract time dependent plasticity parameters from stress relaxation, creep and strain rate sensitivity measurements [1, 2]. However, no systematic comparison of the micromechanical experimental techniques (nanoindentation and microcompression) has been performed on the same material to establish the relative merits and consistency of …

The Measurement Of Viscosity Of Ultrathin Polymer Films, Dariusz Jarzabek, Wojciech Dera, Zygmunt Rymuza

Nanomechanical Testing in Materials Research and Development V

Viscosity is a very important property of thin polymer films used in modern microelectronic technology i.e. in nanoimprint lithography.Hence, in this work we present a method for viscosity of ultrathin polymer films determination. The viscosity is evaluated from the response of the oscillating piezoelectric cantilever at the end of which an indentation probe is mounted (Fig. 1a). When a polymer film is indented, the resonant frequency of the oscillations is changed and the parameters of used model (i.e. Maxwell model) can be identified. The frequency of the oscillations is equal to tens of kilohertz therefore the influence of extremely high …

Investigating The Plastic Deformation Of Molybdenum From -196°C To 950°C Using Nanoand Micro-Indentation, Katherine Plummer

Nanomechanical Testing in Materials Research and Development V

Understanding the plastic deformation at non-ambient conditions is critical to understanding materials’ behaviour in many applications including nuclear power. Molybdenum is seen as a potential candidate for nuclear fusion reactors due to its combination of high melting point and ease of processing. However it will be utilized under some of the most extreme engineering conditions anywhere – temperatures up to 1000K alongside high fluxes of both neutrons and alpha particles. For safe engineering design information on the behaviour of molybdenum under these conditions is needed.

In this work the temperature dependence of plasticity in single crystal Mo (bcc) has been …

Annealing Effect On Coherent-Incoherent Interface Tri-Component Nanoscale Metallic Multilayer Thin Films, Aidan Taylor, Rachel Schoeppner, Megan Cordill, Johann Michler, Hussein Zbib, David Bahr

Nanomechanical Testing in Materials Research and Development V

Multilayer coatings provide an excellent medium for the study of nanoscale materials’ properties. It has previously been shown that Cu/Ni/Nb tri-component multilayers with coherent and incoherent interfaces have a greater capacity for strain hardening than a Cu-Ni/Nb system, in which only incoherent interfaces are present [1]. This experimental evidence supports the predictions of the confined layer slip model in that the modulus-mismatched coherent interfaces in the tri-layer system increase the capacity of the multilayer to store dislocations, leading to greater hardenability.

In this work the same Cu/Ni/Nb tri-layers and Cu-Ni/Nb bilayers are investigated with regard to their thermal stability. In …

Ebsd Investigation Of Microstructure Refinement From Impact-Based Surface Treatments, Xavier Maeder, David Tumbajoy, Sylvie Descartes, Jean Bergheau, Cecile Langlade, Johann Michler, Guillaume Kermouche

Nanomechanical Testing in Materials Research and Development V

The mechanical surface treatments confer better local mechanical properties against wear or fatigue service conditions. In the case of impact-based treatments, a local microstructure’s refinement in the near surface is produced by a severe plastic deformation of the material, leading to a progressive reduction of the grain size over a few tens of microns, and consequently an increase of the hardness and tribological properties. These zones are commonly known as Tribologically Transformed Surfaces (TTS). In this project two different procedures are implemented to obtain TTS surfaces on pure iron samples: Shot-peening treatment and Micro-percussion tests. For the first technique the …

Nanomechanical Testing Of Ods Steels Irradiated With 1 Mev/Amu Heavy Ions, Kateryna Kornieieva, Vladimir Skuratov, Alexander Sohatsky, Jacques O'Connell, Yuri Golovin, Victor Korenkov, Jan Neethling

Nanomechanical Testing in Materials Research and Development V

Heavy ion beams with high damage production rate are widely used to evaluate radiation tolerance of promising nuclear reactor materials, such as oxide dispersion strengthened (ODS) alloys, including their mechanical properties. Since typical ion projected ranges do not exceed 1 micron, nanoindentation technique is the most convenient method for examination of irradiated materials.

In present work we report data on radiation hardening of several ODS steels irradiated with 107 MeV Kr and 167 MeV Xe ions. Some samples were irradiated trough the special Al-foil filter in order to obtain the unfolding damage profile on the surface. The post-irradiation testing steels …

Effects Of Lithiation On The Fracture Toughness And Mechanical Properties Of Limn2o4 Cathode Battery Materials, Marco Sebastiani, K.E. Johanns, Hugues Amanieu, G.M. Pharr

Nanomechanical Testing in Materials Research and Development V

The micro-pillar splitting method has been used to assess the influence of lithiation on the fracture toughness of Li_xMn₂O₄ micro-particles used as cathode materials in lithium ion battery composites. The materials under investigation consisted of hard LiMn2O4 particles embedded in a soft and compliant epoxy matrix to form the composite electrode. Five different samples were extracted from commercial battery cells at different states of charge (SoC% = 0-20-50-75-100%). These correspond to different lithium concentrations in the particles, as measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Experimental results from the pillar splitting experiments show …

Nanoindentation, Micropillar Compression And Nanoscratch Testing Of Zrb2 Grains, Jan Dusza, Tamas Csanadi, Dusan Nemeth, Salvatore Grasso, Mike Reece

Nanomechanical Testing in Materials Research and Development V

The mechanical response under nanoindentation, micropillar compression and nanoscratch tests of ultra-high temperature ZrB₂ ceramic grains were investigated. The tests were carried on selected surface areas where the grain orientations were mapped by electron backscatter diffraction (EBSD) prior to the measurements (Fig.1a). Instrumented indentation were applied for compression using flat punch tip for nanoindentation and nanoscratch tests Berkovich tips were used. Scanning electron microscopy (SEM), atomic force microscopy (AFM) and additional EBSD were performed to study the surface morphology and to characterize the deformations. Strong influence of crystal orientation was observed during micropillar compression while nanoindentation and nanoscratch tests …

Irradiation-Induced Ductilization In The Zr-Based Metallic Glasses, Jaewon Heo, Sunghwan Kim, Seunghwa Ryu, Donchan Jang

Nanomechanical Testing in Materials Research and Development V

Crystalline metals in the nuclear energy system often suffer from the radiation-induced embrittlement which is resulted from the interaction between dislocation motions and the irradiation-induced changes in microstructures. This transition to the brittle failure may lower the mechanical stability of the irradiated components, posing significant threats to the operation and security of the entire mechanical system. In contrast to the crystalline metals, amorphous alloys, often called metallic glasses, have a different plasticity mechanism that does not involve the dislocation motion and hence are expected to exhibit the different irradiation effects on the mechanical from their crystalline counterparts. In this study, …

An Improved Method For Point Deflection Measurements On Rectangular Membranes, Benoit Merle, Kyle Nicholson, Erik Herbert, Mathias Goken

Nanomechanical Testing in Materials Research and Development V

The point deflection method has recently emerged as a possible alternative to current micromechanical techniques for measuring the mechanical properties of thin films. A point deflection experiment consists into deflecting a clamped membrane in its center with a nanoindenter tip. The widespread availability of the required equipment makes the method very promising for future applications. These outlooks were further enhanced by the recent extension of the evaluation theory to rectangular membranes, which – unlike circular ones – are easily fabricated by standard lithographic techniques.

In this work, the recent theoretical advances were critically reviewed and an improved experimental method based …

Orientation Dependence Of Dislocation Transmission Through Twin-Boundaries Studied By In Situ Μlaue Diffraction, Nataliya Malyar, Nagami Jaya, Gerhard Dehm, Christoph Kirchlechner, Jean Sebastuen Micha

Nanomechanical Testing in Materials Research and Development V

It is well known that the grain boundaries (GBs) act as a barrier for dislocation motion (Clark 1992), leading to the well-known strength increase with reduced grain size, as explained by the Hall-Petch relation. Unfortunately the strength increase often leads to a reduction of ductility, except one example: Nano-twinned microstructures. The twin-boundary (TB) dislocation interaction is still not thoroughly understood (Imrich 2014, Gumbsch 2006).

Recent developments in deforming micron sized samples on synchrotron beamlines allow to study the interplay of the single dislocation with a specific grain boundary. In present work we conduct in situ compression on micron-sized copper specimens …

Study Of Sub-Surface Ion-Implanted Hardened Layers With Depth-Sensing Indentation, Alexey Useinov, Boris Chalikh, Pavel Lyamkin, Stanislav Andrianov, Alexander Niktin, Konstantin Kraychuk

Nanomechanical Testing in Materials Research and Development V

Ion implantation is an effective technique for designing structural materials for different industry applications. It may be used to improve various properties of steels such as corrosion resistance, heat resistance, wear resistance, hardness, etc. Based on their origin injected ions may serve as a coating or they may form a new phases such as carbides or nitrides that drastically change the material properties. In this work ferritic martenstic steel was irradiated with Ti and N ions followed with the heat treatment process. It is expected that it would cause the formation of the titanium nitride or titanium carbide precipitates in …

Short Course: Fracture And Adhesion - An Introduction (With Comments On Size Effects), Etienee Barthel

Nanomechanical Testing in Materials Research and Development V

This presentation is meant as a short, handwaving introduction to fracture mechanics and adhesion, a closely related problem. The similarity between the two notions will be underlined throughout the talk.

Trying to avoid technical details, we will first focus on the more general picture, ie how energy flows from the stressed body to the crack tick as the crack propagates (and also how it may flow from the crack tip to the body if allowed to – in the rare cases where the crack closes). We will also examine how these considerations lead to the important notion of crack stability …

Combining In Situ Tensile Testing And Orientation Microscopy In The Sem: A Mems Based Setup For Studying Time Dependent Deformation Of Thin Films By Tkd And Stem, Jan Philipp Liebig, Benoit Merle, Mathias Goken

Nanomechanical Testing in Materials Research and Development V

Structures in integrated devices are constantly subjected to residual or thermal stresses during operation. Understanding the relaxation behavior of thin films is therefore critical for improving their reliability.

Recently it was shown that Transmission Kikuchi Diffraction (TKD) in the Scanning Electron Microscope (SEM) enables the determination of local crystal orientations with high spatial resolution using standard Electron Backscatter Diffraction (EBSD) instrumentation [1, 2]. Giving access to quantitative information on mechanisms like grain growth, grain rotation and strain gradient evolution, time resolved TKD stands out as a promising technique for the characterization of microstructural changes upon relaxation of thin films.

We …

Using In-Situ Microlaue Diffraction To Understand Plasticity In Mgo, Ayan Bhowmik, T. Ben Britton, Finn Giuliani

Nanomechanical Testing in Materials Research and Development V

The present study investigates the micromechanical modes of deformation in MgO prior to cracking at room temperature. A combination of time resolved white beam Laue diffraction technique and in-situ nano-indentation of large single crystal micropillars provides a unique method to study the operating mechanisms of deformation in this otherwise brittle oxide ceramic. Upon indenting an [100]-oriented MgO micropillar, rotation and streaking of Laue spots were observed. From the streaking of the Laue spots, differential slip on orthogonal {110} slip planes was inferred to take place in adjacent areas under the indent - this was consistent with the results from the …

A Comparison Of Nanotribology And Nanoindentation, Steffen Brinckmann, Caroline Fink, Gerhard Dehm

Nanomechanical Testing in Materials Research and Development V

Metal friction and wear is the collective contact and interaction of asperities of micrometer dimension. We use a nanoindenter with tangential force measurement to simulate the behavior in engineering contacts and to fundamentally understand friction and wear.

This presentation investigates the deformation due to a single stroke scratch of a diamond nanoindenter in austenite base. We find that the elastic and plastic equations for static indentation also apply for the dynamic scratching. Additionally, the friction coefficient is found to be normal force dependent and we observe three domains: microstructure dominated friction, plastic plowing dominated wear and wear particle dominated tribology. …