Progress towards Understanding the Synthesis and Behavior of Metals Far from Equilibrium: A SMD Symposium Honoring Enrique Lavernia on the Occasion of His 60th Birthday: Synthesis and Mechanical Behavior
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee, TMS: Advanced Characterization, Testing, and Simulation Committee, TMS: Composite Materials Committee
Program Organizers: Haiming Wen, Missouri University of Science and Technology; Suveen Mathaudhu, Colorado School of Mines; Yuntian Zhu, City University of Hong Kong; Manoj Gupta, National University of Singapore; Kaka Ma, Colorado State University; Troy Topping, California State University Sacramento; Yizhang Zhou, University of California, Irvine; Joshua Yee, Sandia National Laboratories; Dalong Zhang, Pacific Northwest National Laboratory; Yaojun Lin, Wuhan University of Technology; Fei Chen, Wuhan University of Technology
Thursday 8:30 AM
February 27, 2020
Room: 31B
Location: San Diego Convention Ctr
Session Chair: Kaka Ma, Colorado State University; Kyung-Tae Park, Hanbat National University
8:30 AM Invited
Amorphization of Covalently-bonded Solids in Laser-induced Shock: A New Deformation Mechanism in Extreme Loading: Marc Meyers1; Shiteng Zhao2; Bruce Remington3; Chris Wehrenberg3; Hye-Sook Park3; Eric Hahn4; 1University of California, San Diego; 2Lawrence Berkeley National Laboratory; 3Lawrence Livermore National Laboratory; 4Los Almos National Laboratory
Shock compression subjects materials to a unique regime of high hydrostatic and coupled shear stresses. There are, additionally, an attendant temperature increase and the propagation of a shock front at close to sonic velocity, forcing the agents of plastic deformation in metals to nucleate and propagate dynamically. Covalently bonded materials have, by virtue of the directionality of the bonds, great difficulty in responding to this extreme regime by conventional plastic deformation. Here we propose that shock/shear amorphization observed in Si, Ge, B4C, and SiC is a new deformation mechanism in a broad class of covalently bonded materials. The crystalline structure transforms to a higher-density amorphous one along regions of maximum shear stress, forming nanoscale bands, thereby relaxing the shear component of the imposed shock stress. This process is preceded by the emission and propagation of a critical concentration of stacking faults. Molecular dynamics calculations confirm the new mechanism.
9:00 AM Invited
Design, Fabrication and Characterization of FeAl-based Metallic-Intermetallic Laminate (MIL) Composites: Haoren Wang1; Kenneth Vecchio1; 1University of California, San Diego
FeAl-based MIL composites of various iron alloys were fabricated with an innovative “multiple-thin-foil” configuration and “two-stage reaction” strategy. The “multiple-thin-foil” configuration reduces reaction time, enables local chemical composition control leading to microstructures far from equilibrium, which cannot be produced via the conventional methods. Fe-FeAl, 430SS-FeAl, and 304SS-FeAl MIL composites can be synthesized with desired metallic/intermetallic ratios, where FeAl is the single intermetallic phase present in the composites. The transition layer, which forms between the metal and the FeAl intermetallic phase, incorporates the composition gradient, provides a gradual change in mechanical properties, and further functions as a chemical barrier into which other undesired intermetallics dissolve. Driven by diffusion-controlled growth, grains in the transition layers and FeAl regions exhibit ordered arrangement and sintering textures. In compression testing, the compressive strength can reach 2.3 GPa with considerable plasticity, establishing the best mechanical properties of any MIL composites synthesized to date.
9:30 AM Invited
Effects of Processing and Grain size on Very High Strain Rate Deformation of Cu: Kyung-Tae Park1; Keunho Lee2; Seok Bong Kim2; LeeJu Park2; Seong Lee2; 1Hanbat National University; 2Agency for Defense Development
Deformation behavior and microstructural evolution of Cu during very high strain rates over ~105 /s were examined in a wide grain size range of ultrafine (UFG), fine (FG), and coarse (CG) grains. UFG Cu was processed by equal channel angular pressing (ECAP) and FG Cu was processed by low temperature annealing after ECAP. Dynamic tensile extrusion (DTE) tests were carried out for very high strain rate deformation. In the DTE test, a spherical sample is launched from a gas gun with the speed of ~500 m/s to the conical DTE die so that the estimated strain rate reaches over ~105 /s. The DTE fragments were softly recovered, and the microstructure was examined. The deformation characteristics were simulated based on hydrodynamics and compared with experimental. The resultant very high strain rate deformation behavior of Cu will be discussed mainly focusing on the effects of the processing condition and the grain size.
10:00 AM
Nanomechanical Testing of Spark Plasma Sintered Stainless Steel Parts: Alexander Preston1; Kaka Ma1; 1Colorado State University
Gas atomization and cryomilling provide powder materials with microstructure far from equilibrium because of the rapid solidification rate and severe plastic deformation, respectively. The conventional way of producing bulk materials from powders involve long-time exposure to high temperatures, leading to coarsening of the microstructure and near-equilibrium state. Spark plasma sintering can retain the fine grain structure of the feedstock powder and non-equilibrium state via high heating rates. To elucidate the nature of the interaction between electric current with powder particles in SPS, the present work investigated the microstructure and mechanical properties of nominally austenitic stainless steel samples fabricated via SPS of gas atomized powder and cryomilled powder. Nanoindentation and nanoscratch testing at both ambient and elevated temperature were performed to reveal the changes of hardness, wear resistance, and plastic deformation in necks and inter-particle region during SPS compared to those of the center regions in the prior particles.
10:20 AM Break
10:35 AM Invited
Fabrication of Oxides and Semiconductors with Non Equilibrium Phase Content: A. Y. Fong1; G Uahengo1; Y Kodera1; Javier Garay1; 1University of California, San Deigo
Binary and pseudo- binary compounds that appear on the equilibrium phase typically are significantly better studied than those that do not. The advantage of producing non-equilibrium materials could be different and/or better properties than the more common counterparts. Here we discuss strategies for reliably producing relatively large sized samples of oxide and semiconductor material using current activated pressure assisted densification (CAPAD). In one example, we discuss composites composed of cubic (stable) and trigonal (metastable) phases using a combination of high energy ball milling and CAPAD. We present a kinetic study of the densification and cubic to trigonal phase transformation. In the oxide case, we show result of the development of non equilibrium phase content as a result of excellent control of densification vs phase change. In addition, we present transport property and optical measurements to highlight the versatility of eth materials produced.
11:05 AM
Tracer Impregnated nc-materials and Dissolvable Solids for Controlled & Bulk Release Machinable into Downhole Tools for Sensing and Characterization: Indranil Roy1; Ting Roy2; Jing Zhou3; 1DAMORPHE; 2SET Laboratory; 3Rice University
Water and oil soluble tracers, wherein tracer material is a nc-powder or liquid are often used in oilfield for sensing and reservoir characterization. Many attempts have been made to integrate tracers in light weight high strength nc-materials and dissolvable alloys, however unsuccessfully. Here we present our novel approach to include tracers, including quantum dots on silica substrates and nano-electronics into the DNA of nc-alloys and dissolvable materials. Mechanisms encompass matrix mixing and impregnating, in a permeable and porous dissolvable scaffold for controlled & bulk release as well as downhole characterization. Applications are many-fold. Tracer impregnated nc-materials and dissolvable solids can be of any shape or form, for example ball for packers to isolate zones; rings deployed anywhere in a wellbore or proppants to be blended with conventional particulates and injected in the formation. Tracers released from such alloys on reaction with deployed environments can be made to act as timers.
11:25 AM
A Novel Processing Route for Fe-TiB2 High Modulus Steel by Nano-treating and Regular Casting: Shiqi Zheng1; Xiaochun Li1; 1University of California, Los Angles
The design of structural material seeks to increase the strength (YS), while either maintaining or decreasing the density (ρ), which, improves the specific modulus (E/ρ) and the specific strength (YS/ρ). Combining TiB2 and Fe matrix will improve the specific modulus and the specific strength of the matrix, hence named High Modulus Steel (HMS). However, due to the large solubility of TiB2 in Fe matrix (up to 6.5 mol.%), fast cooling process is required to control the TiB2 precipitate size down to submicron or nano-scale. Traditional casting can only produce micro TiB2 precipitate that largely reduce the ductility and mitigate the strengthening effect. In this work, TiB2 nanoparticles are added into molten Fe-Ti-B via a molten salt medium and then cooled slowly to simulate a regular casting. This novel processing route for HMS can circumvent the need for costly processing methods while providing a strong increase of specific modulus and strength.
11:45 AM Cancelled
Achieving Ultrahigh Hardness in Electrodeposited Nanograined Ni-based Binary Alloys: Yinong Shi1; Xiangui Zheng1; Jian Hu2; Jiongxian Li1; 1Imr Cas; 2School of Materials Science and Engineering, East China JiaoTong University
Annealing hardening is of great significance in extremely fine ng metals since it allows hardness to keep increasing with a decreasing grain size that would otherwise be softened. In the present work, direct current electrodeposition was employed to synthesize extremely fine ng Ni-Mo and Ni-P alloys with a grain size of down to a few nanometers. It is demonstrated that the grain size of the as-synthesized extremely fine ng Ni-Mo and Ni-P alloys can be as small as about 3 nm with a homogeneous structure and chemical composition. Grain size strongly depends upon the content of solute atoms (Mo and P). Most importantly, appropriate annealing induces significant hardening to as high as 11 GPa in the two ng alloys, while the peak hardening temperature achieved in ng Ni-Mo is much higher than that in ng Ni-P. Electrodeposition is efficient in the synthesis of ultrahard bulk metals or coatings.