Engineering Ceramics: Microstructure-Property-Performance Relations and Applications: Mechanical Properties of Engineering Ceramics
Sponsored by: ACerS Engineering Ceramics Division
Program Organizers: Young-Wook Kim, University of Seoul; Hua-Tay Lin, Guangdong University of Technology; Junichi Tatami, Yokohama National University; Michael Halbig, NASA Glenn Research Center
Tuesday 8:00 AM
October 11, 2022
Room: 415
Location: David L. Lawrence Convention Center
Session Chair: Junichi Tatami, Yokohama National University; Eita Tochigi, University of Tokyo
8:00 AM Invited
Mechanical Properties of MAX Phases: Miladin Radovic1; Ankit Srivastava1; Rogelio Benitez2; Hemant Rathod1; Zhiqiang Zhan1; 1Texas A&M University; 2University of Texas at Rio Grande Valley
The class of ternary carbides and nitrides known as the MAX phases share common unique naonolayered structure and chemical formula Mn+1AXn, where n = 1, 2 or 3, M is and early transition metal, A is an A-group element (mostly IIIA and IVA) and X is either C or N, represent a new class of solids. The main reason for growing interest in MAX phases lies in their unusual, and sometimes unique properties. In general, MAX phases are elastically stiff, good thermal and electrical conductors, resistant to chemical attack, and have relatively low thermal expansion coefficients, but also relatively soft and most readily machinable, thermal shock resistant and damage tolerant. Therefore, MAX phases are considered to be a good candidate materials for structural applications in extreme environments. This presentation provides an overview of the current understanding of mechanical behavior of MAX phases and their failure and deformation mechanisms.
8:30 AM
Tunable Self-Assembly of 2D Carbide MXenes with Bulk Ultra High Temperature Ceramics: Nithin Balachandran1; Yooran IM2; Srinivasa Kartik Nemani2; Ravi Kumar3; Babak Anasori2; 1IIT Madras, Chennai; 2Indiana University-Purdue University Indianapolis; 3IIT Madras
2D transition metal carbide MXenes are recently being explored for their high-temperature stability up to 2000 ŗC under inert atmospheres. High-temperature studies on Ti3C2Tx MXene have shown phase transformation to the cubic TiCy. In this study, we explore the tailorable preparation of green bodies of nanometer-thick Ti3C2Tx MXene with bulk ultra-high-temperature ceramic (UHTC) materials such as zirconium carbide (ZrC) and zirconium diboride (ZrB2) via electrostatic self-assembly. Because of the 2D sheet morphology of MXenes and their negative zeta potential (~ -34 mV for Ti3C2Tx in pH = 4), homogeneous self-assembly occurs upon mixing UHTC particles with MXenes. As a result of this self-assembly, the UHTC particles are wrapped by MXene sheets. This method allows us to explore a surfactant-free, water-based, one-pot green body preparation of UHTC composites. The fundamental study of the self-assembly mechanism of Ti3C2Tx MXene with bulk ceramics can pave new routes for processing UHTC composite green bodies.
8:50 AM
Deviations from Hall-Petch Relationships in Nanocrystalline Ceramics: Heonjune Ryou1; Kevin Anderson1; John Drazin2; Edward Gorzkowski1; Boris Feygelson1; James Wollmershauser1; 1U.S. Naval Research Laboratory; 2UES Inc.
Advancement in ceramic synthesis and manufacturing processes in recent years has enabled production of nanocrystalline ceramics with extremely small grain sizes: well below 100 nm. Many studies have reported the extent of the mechanical property improvement in nanocrystalline ceramics, which typically follows a conventional Hall-Petch relationship. However, there are cases when the hardness of nanocrystalline ceramics deviates from conventional Hall-Petch relationships. In this presentation, various nanocrystalline ceramics with grain sizes below 100 nm were characterized by instrumented indentation and two different types of deviation from conventional Hall-Petch relationships are observed in nanocrystalline ceramics. One type of deviation is a decrease in hardness below a certain grain size which suggests a change in strain accommodation mechanism at extremely small grain sizes. Another type of deviation is a shift in Hall-Petch line which suggests the superposition of multiple strengthening mechanisms.
9:10 AM
Advanced WC-Al2O3-ZrO2 Composites with Improved Metal-cutting Performance for Super Alloys: Zhenyu Liu1; 1Kennametal Inc
WC-Al2O3 ceramic composite system was investigated as an engineering ceramic system. Al2O3 is a typical material for structural application because of its high hardness and chemical inertness at high temperature, while WC is often used as a superhard material. As a matter of fact, a combination of Al2O3 and WC is expected as a potential candidate for cutting-tool materials. Control of heterointerfaces in advanced composite materials is of scientific and industrial importance, because their interfacial structures and properties often determine overall performance and reliability of the materials. Here distinct improvement of mechanical properties and cutting performance of WC-Al2O3 were achieved by adding of ZrO2 into Al2O3-WC system. Microstructures and interfaces in the composites are characterized by advanced techniques including X-ray diffraction, scanning electron microscopy, electron back scattering diffraction and transmission electron microscopy, and it is expected to obtain the correlation of microstructure, property and performance.
9:30 AM
A Simple Constitutive Law for Comminuted Ceramics under Multi-axial Loading: Bryan Love1; 1DEVCOM Army Research Laboratory
The flow of comminuted ceramic during multi-axial loading is relevant to longstanding challenges in penetration mechanics for Army applications. Here, we seek to develop a robust, “necessarily complex” constitutive model for use in hydrocodes that takes into account, on average, the evolution of particle sizes and its effect on the pressure-volume and shear behavior of the fractured material. Concepts common to geological/granular materials, such as interparticle locking/jamming, are incorporated into both elastic moduli and flow strength. Relevant ceramics are fully dense during their initial comminution, with free volume only arising during the subsequent shearing of the material, requiring extension of theories towards limiting cases. Careful consideration is given towards numerical simplicity and stability—critical when a constitutive model is evaluated billions of times in a single simulation. The resulting model is demonstrated by illustrating observed physical phenomena from multi-axial experiments that were not present in its predecessors.
9:50 AM Break
10:10 AM
Electrochemical Fabrication of Microstructure Engineered, Highly textured, Ultra-thick Ceramic Oxide Films for High Volumetric Energy Density Electrochemical Energy Storage: Arghya Patra1; Paul Braun1; 1University of Illinois Urbana Champaign
Anisotropic ceramic oxides exhibit drastically different physico-chemical properties along different crystallographic directions. However, translation of crystal-level anisotropy to a length scale of hundreds of microns in a film form factor has been elusive in ceramics important for electrochemical energy storage. State-of-the-art synthesis of layered transition metal oxide cathodes for Li-ion battery involves prolonged high temperature (>700°C), thus generating untextured powders. Employing a molten hydroxide-based electrodeposition method, we demonstrate textured LiCoO2 films with controllable in-and-through-plane orientation, grain size, grain type and grain distribution. The highly textured, ultra-dense (>95%) electrodeposits exhibit low tortuosity and fastest electron and Li ion conducting pathways oriented normal to the current collector. Such microstructure engineered cathodes can perform even at ultrahigh thickness of ~200 µm (areal capacity of ~15 mAh/cm2) in comparison to ~50 µm for conventional slurry cast cathodes (areal capacity of ~3 mAh/cm2, 80% dense), a fourfold increase in areal capacity and volumetric energy density.
10:30 AM
The Ball-on-Three-Balls-Test: Improving Accuracy and Simplifying Stress Evaluation: Maximilian Staudacher1; Tanja Lube1; Peter Supancic1; 1Montanuniversität Leoben
The Ball-on-Three-Balls-Test has proven to be an accurate and easy-to-use option for strength testing. However, the maximum stress must be calculated based on Finite-Element-Analysis (FEA) results. For this purpose, a fitted function was provided in 2002. This function is based on results which were generated under the assumption of punctiform load introduction. Deviations from these ideal conditions occur through large specimen deformations, plastic ball deformation, friction, or an increase in contact-area between the balls and the specimen. These non-linear effects are investigated by FEA for a wide range of specimens. It is shown that the maximum stress is sensitive to the area of contact between the loading ball and the specimen. Furthermore, thin specimens are subject to large deformations, which significantly decrease the maximum stress. Therefore, a revised fitted function is presented. For specimens with exceptional geometries, non-linear effects are considered with adjustment factors added to the new fit function.