Deformation Mechanisms, Microstructure Evolution, and Mechanical Properties of Nanoscale Materials: Small Scale and In-situ Testing
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Nanomechanical Materials Behavior Committee
Program Organizers: Niaz Abdolrahim, University of Rochester; Matthew Daly, University of Illinois-Chicago; Hesam Askari, University Of Rochester; Eugen Rabkin, Technion; Jeff Wheeler, Femtotools Ag; Wendy Gu, Stanford University
Wednesday 8:30 AM
March 22, 2023
Room: Aqua 300AB
Location: Hilton
Session Chair: Jeffery Wheeler, FemtoTools AG; Eugen Rabkin, Technion
8:30 AM Invited
Understanding Deformation Mechanisms in Ultrafine Grained Thin Films by Quantitative In Situ TEM Deformation: Josh Kacher1; 1Georgia Institute of Technology
Ultrafine grained thin films exist in a mechanistic gray area where both grain boundary and transgranular dislocation activity play important roles in accommodating plasticity. Quantitative in situ transmission electron microscopy (TEM) deformation experiments provide direct resolution of deformation processes while simultaneously recording stress and strain information. In this talk, I will discuss the application of a custom MEMS-based quantitative deformation platform for in situ TEM testing of ultrafine grain Al and Au thin films. Discussion will focus on the influence of microstructural character, such as grain size, orientation, and grain boundary characteristics, on the active deformation mechanisms. Special attention will be given to grain boundary mediated deformation via grain boundary sliding and disconnection activity. The ability to measure variations in activation volume as a function of material characteristics and environment will be demonstrated through testing of irradiated samples and electron beam effects during deformation.
9:00 AM
Direct Measurement of Adhesion for Noble-metal Nanoparticles Using In Situ Transmission Electron Microscopy: Andrew Baker1; Sai Bharadwaj Vishnubhotla1; Sanjana Karpe1; Yahui Yang1; Goetz Veser1; Tevis Jacobs1; 1University of Pittsburgh
A key aspect of metal nanoparticle technologies is how strongly the nanoparticles adhere to their supports. This adhesion controls the efficiency and lifetime of many nanoparticle applications. In the present work, in situ adhesion tests were performed inside of a transmission electron microscope (TEM) on nanoparticles of gold and platinum with different supporting oxides. The advantage of this technique is the combination of Angstrom-scale characterization of particle size, shape, and structure coupled with nanonewton-scale measurements of adhesive forces. Together, by measuring adhesive force and contact area, this technique can measure the adhesive strength on a particle-by-particle basis. First, the accuracy of the technique was assessed based on comparison to prior approaches; then the adhesive strength was measured for new material combinations that had not previously been investigated. Finally, the advantages of this technique were utilized to study structure-properties relationships, including the effect of particle shape and size on adhesion.
9:20 AM
Anisotropy Characterization via Correlated Mechanical Microscopy and EBSD: Jeff Wheeler1; 1Femto Tools Ag
Mechanical microscopy is an emerging technique using high-speed nanoindentation to map the mechanical behavior and extract phase-level properties from complex microstructures with micron-scale lateral resolution. As such, this is an ideal method to study mechanical properties variation with crystal orientation within polycrystalline materials in a high-throughput manner. These produce statistical distrbutions in mechanical properties which are a function of the elastic and plastic anisotropy of the material. In this work, we combine nanoindentation mapping and EBSD to achieve correlated datasets to provide new insights into anisotropy in mechanical properties.
9:40 AM
Challenges in Cross Sectional Nanoindentation of Multilayers in Modern Electronics: Stanislav Zak1; Megan Cordill1; 1Erich Schmid Institute of Materials Science, Austrian Academy of Sciences
Nanoindentation is a great tool for assessment of materials hardness and elastic modulus in a high-throughput and controllable manner. It becomes a necessary tool when the material properties of thin films and micro- to nano-level structures are in question. However, multi layered functional materials commonly used in microelectronics are not physically accessible, hence, cross sectional characterization has to be used. However, due to large differences in stiffnesses between the used materials in a stack (metals – ceramics – polymers), the cross sectional nanoindentation may be influenced by the lateral deformation of the surrounding, different materials. Effectively leading to sensing not only the measured material, but the whole stack, creating erroneous results. Presented work shows nanoindentation results of thin layers close to different interfaces with emphasis on use of different indenter tips and indentation depths, in combination with numerical modelling to quantify the stress-strain fields within the sample.
10:00 AM Break
10:20 AM Invited
3D Synchrotron Imaging of Mechanical Properties of Nanoscale Materials: Marie-Ingrid Richard1; Maxime Dupraz1; Corentin Chatelier1; Clément Atlan1; Sarah Yehya2; David Simonne2; Stéphane Labat3; Steven Leake4; Ewen Bellec4; Olivier Thomas3; Eugen Rabkin5; 1CEA Grenoble; 2Synchrotron SOLEIL; 3IM2NP-CNRS; 4ESRF; 5Technion
The advent of the world’s first coherent hard x-ray sources represents an unprecedented opportunity to conduct in situ and operando studies on the structure of nanoparticles using 4th generation synchrotron sources. In this talk, I will illustrate how Bragg coherent x-ray imaging allows to image in three dimensions (3D) and at the nanoscale the strain and defect dynamics inside nanoparticles during heat treatment and catalytic reactions. This imaging technique can be coupled with molecular statics simulations to investigate the 3D strain and stress fields in nanoparticles. I will also highlight the potential of machine learning to predict characteristic structural features in nanocrystals just from their 3D Bragg coherent diffraction patterns.
10:50 AM
In Situ Nano-identation of a Pt Nanoparticle Coupled with Bragg Coherent X-ray Diffraction Imaging: Sarah Yehya1; Thomas Cornelius2; Marie-Ingrid Richard3; Felisa Berenguer1; Eugen Rabkin4; Olivier Thomas2; Stéphane Labat2; 1Synchrotron SOLEIL; 2AMU - CNRS; 3CEA of Grenoble; 4Technion Institute of Technology
Defects in nanocrystals have a critical influence on material properties, where a single defect can completely modify physical and chemical behavior. Here, we report on synchrotron experiments that consist of in situ annealing and indentation of Pt nanoparticles combined with Bragg coherent X-ray Diffraction Imaging (BCDI). This latter allows imaging the 3D structure of individual nano-objects with spatial resolution of 10 nm and picometer sensitivity of displacement fields and is well suitable to investigate the stability of defects in nanocrystals during mechanical loading. Selected nanoparticles were indented using a custom-built AFM in the intention of inducing defects in them at room temperature. Coherent diffraction patterns were also recorded continuously at room temperature as well as while annealing the sample under air for several nanoparticles. Thanks to BCDI it was possible to visualize the induced defects after indentation and their mobility in reconstructed Pt nanocrystals in 3D while annealing the sample.
11:10 AM
Recent Advances in Bragg Coherent Diffraction for Nanoscale Imaging of Strain: Ross Harder1; 1Argonne National Laboratory
Bragg Coherent Diffraction Imaging (BCDI) offers nanoscale resolution imaging with high sensitivity to distortions of the sample lattice. This talk will introduce the technique and describe recent improvements at the BCDI instrument of the Advanced Photon Source (APS) for imaging submicrometer scale crystalline objects. The new capability enables in-situ determination of crystallographic orientation via broadband Laue Diffraction Microscopy. With the full knowledge of the orientation of a specific sub-micrometer scale crystal one can measure coherent diffraction around multiple Bragg peaks of the lattice. With such data sets the full strain tensor of the sample can be imaged with tens of nanometer resolution at current generation synchrotrons. The pending upgrades to machines like the APS will significantly improve the capabilities of coherent techniques. We anticipate sub nanometer scale resolution imaging at the new instruments being developed.
11:30 AM Invited
Mechanical Properties of Nanowires: From In-situ Experiments to High Throughout, Statistically-significant Testing: Rodrigo Bernal1; 1University of Texas at Dallas
Nanowires find applications ranging from nanodevices, which utilize individual nanostructures, to nanostructured materials, which utilize millions of them. Individual-nanowire mechanical testing, especially coupled with in-situ microscopy, has revealed important insights into their elastic and failure properties. These insights have been instrumental for nanodevice design, and to predict how nanowires might behave in macroscale nanostructured materials. However, nanostructured materials employ millions of nanostructures to achieve function, thus requiring new experiments that reveal statistical failure information. In this talk, I will describe our efforts to characterize elasticity, failure, and plasticity of individual nanowires, and how this knowledge now informs novel high-throughput testing techniques. These new techniques, based on microfluidics and self-assembly, allow us to pattern in an ordered way many nanowires over flexible substrates, for subsequent testing and analysis. The techniques allow us to obtain failure, strength, and fatigue statistics, which are important for nanostructured materials such as stretchable electronics.