2020 Technical Division Student Poster Contest: SMD 2020 Technical Division Graduate Student Poster Contest
Sponsored by: TMS Extraction and Processing Division, TMS Functional Materials Division, TMS Light Metals Division, TMS Materials Processing and Manufacturing Division, TMS Structural Materials Division
Program Organizers: TMS Administration
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
SPG-52: Atomistic Oxide Structures and Stoichiometry of Chromium Steel by Grand Canonical Monte Carlo Simulations with ReaxFF Potential: Qian Chen1; Chang Liu1; Yang Wang1; Narumasa Miyazaki1; Yusuke Ootani1; Nobuki Ozawa1; Momoji Kubo1; 1Tohoku University
To improve the reliability of chromium steels in power plants, it is important to understand the structure and stoichiometry of passive oxide film of chromium steels at atomic scale; however, they are difficult to be achieved by the experimental observations. Although molecular dynamics simulation with reactive potentials such as ReaxFF is effective to study the atomic-scale reaction dynamics in nano-second order, it is incapable to study the formation process of oxides, because the oxide formation process needs hundreds of hours. To study the oxide structures and stoichiometry at atomic-scale, we developed a Grand Canonical Monte Carlo simulator combined with a ReaxFF-based optimization. We successfully reproduced various oxide structures and stoichiometry of Fe-Cr solid solution with different oxygen partial pressure. This simulator enables us to assess the structure and thermodynamic properties of oxides at atomic scale and provides reasonable modeling approach for further research on deterioration mechanism coupled with chemical reaction.
SPG-53: Deformation Mechanisms in Immm-Ni2(Cr,Mo,W)-containing Haynes® 244® Superalloy: Thomas Mann1; Michael Farhmann2; Michael Titus1; 1Purdue University; 2Haynes International
Haynes® 242® and 244® alloys are strengthened by a Immm-Ni2(Cr, Mo, W) body-centered orthorhombic (BCO) intermetallic phase. Due to the low symmetry of this phase, the deformation mechanisms are expected to be complex, and a myriad of planar defects are predicted to be observed on the {013} planes, which are nearly co-planar to the matrix {111} plane. These defects include those analogous to the γ’ phase: superlattice intrinsic/extrinsic stacking faults, antiphase boundaries, and complex stacking faults. To assist in the analysis of favorable shear pathways of dislocations through the precipitate, we utilized ab-initio density functional theory calculations to determine the planar defect energies. The energy of these faults was determined by creating a supercell with the c axis parallel to the {013} plane normal and tilting the cell along the slip vector associated with the planar defect. These calculations were then used to create a Generalized Stacking Fault Energy surface.
SPG-54: Dependence of Crystallographic Orientation on the Microstructural Evolution of Ni-based Single Crystal Superalloys-A Synergistic Experimental-computational Analysis: Harikrishnan Rajendran1; Jean- Briac le Graverend1; 1Texas A&M University
Single-crystalline turbine blades, made of Ni-based superalloys, are cast in <001> direction. Turbine blades exhibit strong material anisotropy, and there exists a significant microstructure-property relation with regards to their crystallographic orientation. From our high-temperature/low-stress creep experiments and the subsequent microstructural characterization, we observed that the orientation of γ’ precipitates and direction of rafting is at 45-degrees to the load axis in <011> but is parallel/ perpendicular to the load in <001>. Therefore, to elucidate the dependence of crystal orientation on the microstructure and properties, a new phase-field model capable of predicting cuboidal and rafted microstructures for <001> and <011> crystal-orientations is introduced. Statistical volume elements (SVE) were then generated from 3D phase-field microstructures having various γ/γ’ realizations. Finally, macroscale strain-controlled tensile tests were performed on the SVEs using a finite-element crystal plasticity framework.
SPG-55: Combinatorial and High-throughput Experiments on Ni-based Alloy Thin Films: Taeyeop Kim1; Donghyun Park1; Euimin Cheong1; Daegun You1; Hehsang Ahn2; Eun Soo Park2; Dongwoo Lee1; 1Sungkyunkwan University; 2Seoul National University
Many of the structural materials designed for harsh environments are multicomponent alloys, and thus the investigation of the composition-dependent properties is desired to optimize the alloys’ functionality. This process, however, can be tedious as the number of possible combinations of the compositions of multicomponent alloys is enormous. Combinatorial synthesis and high-throughput experiments offer an effective route to acquire a large number of experimental property data. To characterize composition-dependent phase stabilities and physical properties of solid solution strengthened Ni-based alloys, we combinatorially synthesized Ni-Fe-Cr ternary systems and carried out high-throughput measurements. We used magnetron co-sputtering to fabricate the thin film materials library and performed x-ray diffraction, nanoindentation, and 4-probe resistance mapping experiments. We discuss the experimental results and the composition optimization process for the Ni-based alloys with high strength.
SPG-56: Core Effect of Local Atomic Configuration and Design Principles in AlxCoCrFeNi High-entropy Alloys: Yu-Chia Yang1; Cuixia Liu2; Chun-Yu Lin1; Zhenhai Xia1; 1University of North Texas; 2Xi'an Technological University
High-entropy alloys (HEAs) are known to have four core effects leading to superior properties over traditional alloys. Here we investigate an additional core effect, local atomic configuration, due to inherent variations of local chemical composition at the nanoscale. The stacking fault and twin formation energies of AlxCoCrFeNi HEAs, calculated with density functional theory methods, show large variations and even negative energies due to the local atomic configurations. A design principle is proposed to predict the mechanical properties and stacking fault energies of the HEAs by controlling the chemical composition. The effect of temperature on stacking fault energy is also determined, which is consistent with experimental results.
SPG-57: Cycling Corrosion Testing of Bi-metallic Joints Between Al And Mg Alloys: Qingli Ding1; Brajendra Mishra1; Kubra Karayagiz1; Adam C Powell1; 1Worcester Polytecnic Institute
Cyclic Corrosion Test (CCT) is now being considered as a more realistic method than the traditional steady-exposure methods, such as salt spray tests. In this project, under conditions without coatings that comprises worst case, we are conducting CCT method on the next generation Magnesium-Aluminum Vehicle Joints which are 50% lighter than the conventional steel-based alloy. Following the SAE J2334 standards, the detailed corrosion procedure will be monitored by linear polarization resistance (LPR). Scanning Electron Microscopy (SEM) will characterize the surface change and the existence of stress corrosion can be detected by the X-ray diffraction (XRD).
SPG-58: Effect of Annealing and Partitioning Temperature of 10 wt pct. Mn steel in RT Q&P Process: Dong Hwi Kim1; Jee-Hyun Kang2; Joo Hyun Ryu3; Sung-Joon Kim1; 1POSTECH; 2Yeungnam University; 3POSCO
Medium Mn steels are potential candidates of the 3rd generation advanced high strength steels. One of the methods for enhancing the mechanical properties applied to medium Mn steel is quenching and partitioning (Q&P) process. In this research, room temperature quenching was introduced for simple Q&P process using Fe-0.2C-10Mn-2Al steel. The difference of tensile properties with different annealing histories and the effect of partitioning were investigated. To obtain diverse phase fractions, three different annealing temperatures, 700, 750 or 800 °C, were used. After annealing at 700 °C, the microstructure consisted of ferrite and austenite. In contrast, martensite and austenite structure was obtained from the other two annealing temperatures. Partitioning process was carried out in the temperature range of 100~300 °C, and the improvement of elongation was achieved by partitioning at 200 and 300 °C. The resulting tensile properties were comparable to those produced by conventional Q&P medium Mn steels.
SPG-59: Effect of Replacing Ni by Cu on Hydrogen Embrittlement in Austenitic Stainless Steel: Hyung Jun Cho1; Sung-Joon Kim1; 1POSTECH, Korea
Austenitic stainless steels are mainly used as structure materials for hydrogen facilities due to their high hydrogen embrittlement resistance. In this work, three austenitic stainless steels that have different contents of Ni and Cu were investigated to elucidate the effect of Ni and Cu on phase stability and hydrogen embrittlement. XRD analysis revealed that Cu stabilizes the austenite phase as effectively as Ni. However, the degree of hydrogen embrittlement increased as Ni was replaced by Cu. The amount of desorbed hydrogen and deformation mode differed in the three alloys. Diffusivity increased but solubility decreased as Ni was replaced by Cu. In addition, twinning was the main deformation mode in Ni-added alloy, while tangled dislocation developed in Cu-replaced alloy. These factors seemed to cause difference in microcrack initiation and propagation after hydrogen charging and deformation. Thus, different interaction with hydrogen and dislocation behavior was responsible for the difference in hydrogen embrittlement.
SPG-60: Effects of Pore Geometry and Location on the Material Properties of Additively Manufactured Ti-64: Connor Varney1; Nicholas Telesz1; Robert Quammen1; John Balk1; Andrew Wessman2; Paul Rottmann1; 1University of Kentucky; 2University of Arizona
Additive manufacturing (AM) has seen large interest in recent years for the ability to print parts for immediate service. Thus far, there is tremendous difficulty in replicating the properties of conventionally manufactured metals due to complex processing conditions. This research focuses on analyzing and quantifying the differences of two batches of AM Ti-64 rods with measurably different properties that were printed under nominally the same conditions. The defects in these samples were characterized using optical and electron microscopy. Fatigue testing was performed on the samples, with results compared to other traditional and additive literature. It was found that lenticular pores were significantly more deleterious than spherical pores. Models predicting fatigue limits and stress intensity factors are also discussed. The research presented demonstrates that the percent porosity of AM metals alone is insufficient: the size, shape, and location of pores within the part are critical to adequately predict part properties.
SPG-61: Evaluation of the Magnitude and Directionality of Residual Stress on SUS316L using Instrumented Indentation Test: Kyungyul Lee1; Jong-hyoung Kim1; Junsang Lee1; Byungchul Kim2; Michael Prime3; Dongil Kwon1; 1Seoul National University; 2FRONTICS Inc.; 3Los Alamos National Laboratory
Residual stress is stress that remain in material after the original cause of the stresses has been removed. It is often a cause of premature failure of critical components, and was probably a factor in the collapse of structure. Therefore, quantitative evaluation of residuals stress in structural materials is important. Residual stress measurement techniques such as saw cutting and contour method are limited by being destructive methods. Scanning methods such as XRD and neutron diffraction methods are non-destructive but extremely sensitive to the test environment. To overcome these limitations, an instrumented indentation test(IIT) has been developed from hardness test. IIT measures the indenting load and penetration depth in real time and displays it as a continuous curve. Recent researchers have analyzed this curve and developed it to evaluate mechanical properties and residual stress. This presentation introduces the results of joint research with the Los Alamos National lab using IIT.
SPG-62: Experimental and Thermodynamic Modelling of Binary Phase Diagrams Under Pressure: Moran Emuna1; Aviva Melchior2; Eyal Yahel2; Guy Makov3; 1Ben Gurion University and NRCN; 2NRCN; 3Ben Gurion University
Binary phase diagrams are of scientific and practical importance in material science. In particular, they represent the stability regions of solid and liquid phases formed by the two components. Pressure affects phase diagrams both by altering the interactions, which control the nature of the diagram, and by the emergence of new phases and phase boundaries. In the present contribution we study the pressure evolution of several binary systems (Bi-Sb, Pb-Sb) by accurate sound velocity measurements, XRD in diamond anvil cell (DAC), density measurements and advanced thermodynamic model which describe the pressure dependence of the systems. By incorporating pressure into the model and validating the results against accurate measurements, we are able to predict the pressure dependence of binary phase diagrams; including changes in the nature of the diagram, shifts of eutectic points and the evolution of interaction parameters with pressure.
SPG-63: Experimental Investigations and Thermodynamic Modeling of the Mo-Nb-Re Ternary System: Shao-Yu Yen1; Shu-chang Wu1; Muhammad Anshar Makhraja1; Kai-chi Lo2; An-chou Yeh2; Kyosuke Yoshimi3; Chuan Zhang4; Shih-kang Lin1; 1National Cheng-Kung University; 2National Tsing Hua University; 3Tohoku University; 4CompuTherm LLC
With ultra-high strength and temperature creep resistance, superalloys are widely used in aerospace and defense industries. In order to increase the operation temperature of turbine engines for higher efficiency, refractory elements with high melting points are usually alloyed in next-generation superalloys. In this work, ab initio aided-CALPHAD was employed for the thermodynamic modelling of Mo-Nb-Re ternary and sub-binary systems. With the ground-state energies obtained from ab initio calculations, experimental difficulties at low to moderate temperatures due to sluggish kinetics can be avoided. Mo-Nb, Nb-Re and Mo-Re were re-assessed successfully and extrapolatable to the ternary system. Due to the lack of experimental data for CALPHAD optimization, high-temperature phase equilibria of the Mo-Nb-Re ternary systems, namely the isothermal sections at 1973 K, 2173 K, and 2373 K, were experimentally determined. With the ab initio energetics and experimentally determined phase equilibria, the thermodynamic description of the Mo-Nb-Re ternary system was assessed and proposed.
SPG-64: First-principles Calculations of Non-dilute Solute Diffusion Coefficients in the Ag-Au System: Kristin Mackowski1; Chelsey Hargather1; 1New Mexico Institute of Mining & Technology
Diffusion is the main mode of mass transfer in solid materials, and is crucial to understanding specific mechanical properties and failure mechanisms of materials. Calculating the diffusion related properties using first-principles techniques for self-diffusion and in the presence of one solute atom are well established. The present work uses first-principles calculations based on density functional theory and the 14-frequency model to calculate all of the possible jump frequencies of lone and paired solute atoms in a host matrix. Calculations are performed within the generalized gradient approximation as implemented for solids using a 108-atom supercell. The calculations are first completed in a silver host system with single or paired gold solute atoms. Calculations are compared to experimental data when available. The nudged elastic band method is used to calculate the minimum energy pathways of the diffusing atoms. All calculations are performed as a function of temperature using the quasi-harmonic Debye model.
SPG-65: Hydrogen Effect on 15Cr-15Mn-4Ni based Stable Austenitic Stainless Steels with Carbon or Nitrogen: Kyung-Shik Kim1; Jee-Hyun Kang2; Sung-Joon Kim1; 1POSTECH; 2Yeungnam University
Stable austenitic stainless steels are used as structural materials for hydrogen environment due to high solubility and low diffusivity of hydrogen and the suppression of martensitic transformation. Carbon and nitrogen are reported to enhance the resistance to hydrogen embrittlement in the sense of stabilizing austenite. Fe-15Cr-15Mn-4Ni based steels with 0.3 weight percent of carbon or nitrogen were electro-chemically charged with hydrogen and deformed to investigate the degradation of tensile properties from hydrogen with each interstitial element. The elongation of both alloys decreased, and the cracks formed at the surface were found to be responsible for the degradation. Cracks were initiated at the triple junction of the grain boundaries. With carbon, the cracks propagated inside the specimen through grains forming cleavage fracture, whereas with nitrogen, intergranular fracture was observed. Strain hardening rates went through different trends and the different effects of carbon and nitrogen on hydrogen embrittlement could be explained.
SPG-66: Improvement on Anisotropy and Mechanical Behaviors of IN718 Processed by Selective Laser Melting by CoAl2O4 Inoculant Addition: I-Ting Ho1; Tzu-Hou Hsu2; Yao-Jen Chang2; Chen-Wei Li3; Kai-Chun Chang2; Sammy Tin1; Koji Kakehi3; An-Chou Yeh2; 1Illinois Institute of Technology; 2National Tsing Hua University; 3Tokyo Metropolitan University
This study aims to investigate the effects of minor addition of CoAl2O4 inoculants on crystallographic texture and mechanical properties of a superalloy – Inconel 718 (IN718), processed by selective laser melting (SLM). IN718 powder was blended with 0.2 wt. % of CoAl2O4 flakes uniformly. After SLM process, these particles were found to affect the crystallographic texture and reduce the anisotropic grain structure. Furthermore, there was a dispersion of nano-oxides in the microstructure induced by reaction between IN718 and CoAl2O4 particles; finer grain structure could be achieved after post-heat-treatment. Through the tensile testing, it could be observed that the inoculant addition had significantly minimized the elastic anisotropy and enhanced the tensile strength. This work has demonstrated the beneficial effect of inoculant in additive manufactured superalloys.
SPG-67: In-situ Mechanical Characterization of Micro-scale NiTi Shape Memory Alloy Tensile Bars: Injong Oh1; Ho Jang Kim1; Won Seok Choi2; Hosun Jun3; Pyuck-Pa Choi3; Wael Zaki4; Gi-Dong Sim1; 1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; 2Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST); 3Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; 4Department of Mechanical Engineering, Khalifa University, Abu Dhabi, UAE
Shape memory alloy (SMA) thin films have capacity of recovering initial shape after heating, following the deformation. Furthermore, SMAs reveal another ability, called superelasticity, which bounces back deformation upon unloading. In behalf of these capacities, SMA have been expected to achieve high performances when applied for microactuators. However, mechanical behavior of micro-scale SMAs thin films are not deeply understood yet. In this poster, we present our recent study on in-situ mechanical characterization of micro-scale Nickel Titanium (NiTi) tensile bars. With the help of MEMS (Micro-Electro-Mechanical Systems) fabrication techniques, hundreds of specimens with various design were fabricated in a single fabrication process. The mechanical properties of NiTi tensile bars are quantified by utilizing an in-situ SEM nanoindentation system equipped with focused ion beam (FIB) milled diamond micro gripper. Micro-scale tensile bars are proved to be an effective way to fabricate samples in a high-throughput manner and scrutinize the mechanical properties.
SPG-68: Investigation into the Occurrence of Electromigration for Aluminum: Microstructure and In-situ XRD Study: Kuan-Hsueh Lin1; Yu-chen Liu1; Ching-Shun Ku2; Shang-Jui Chiu2; Shih-kang Lin1; 1National Cheng Kung University; 2National Synchrotron Radiation Research Center
Electromigration becomes the most important cause of failure for future device since the ever-raising current density. The concept “critical product” was first proposed for aluminum thin film by Blech. However, our preliminary study showed that the Blech critical product cannot explain the occurrence of electromigration for strips in 500 microns long or longer. In this study, in-situ current stressing was conducted under fixed temperature. The relation between lattice strain and hillocks formation was discussed. It was observed that over a critical strain, hillocks tend to form and a permanent diffraction peak shift occurred. The critical strain was found to be around 0.8% for strip ranging from 500 to 20000 microns. First principle calculation showed the difference of diffusion barrier under this strain and further TEM investigation was conducted to compare the microstructure change after the hillocks formation. The strain-driven electromigration mechanism is elucidated in this poster presentation.
SPG-70: Irradiation Cluster Defect Distribution on Fe Nanoparticle by MD Simulation: Mohammad Khan1; 1University of Idaho
In this work molecular dynamics (MD) simulations were conducted to explore the primary radiation effects on Body-Centered Cubic (BCC) Fe nanoparticle. A series of 6 cascades for each primary knock-on atom (PKA) energy (5 keV, 10 keV, 20 keV, 30 keV and 40 keV) was simulated to assure statistical precision. It has been observed that defects created by neutron irradiations stay as a single to several size clusters. In each of the cases, they produce one block of a big cluster with several small clusters. The block cluster of interstitials (Is) stays at the near surface of the nanoparticle, however, vacancies (Vs) stay inside the nanoparticle. The study has shown that the total number of vacancy defects is larger than the total number of interstitial defects.
SPG-71: Kinetic Evolution of Metastable Grain Boundaries under
Non-equilibrium Processing: Zhitong Bai1; Glenn Balbus2; Daniel Gianola2; Yue Fan2; 1University of Michigan, Ann Arbor; 2University of California, Santa Barbara
The energetic evolution of a group of Cu <100> symmetric tilt grain boundaries (GBs) subjected to fast thermal cycling are investigated via atomistic modeling, wherein a universal hysteretic response is observed. Utilizing an efficient data-mining algorithm, the GBs’ energetic evolution rates are mapped out over the metastability-temperature space, wherein two distinct regimes—an ageing regime and a rejuvenating regime—are retrieved with high fidelity. We further demonstrate that the ageing/rejuvenating crossover can be attributed to the energy imbalance along with the sequential hopping in the system’s underlying potential energy landscape. Such a kinetic analysis enables a self-consistent equation describing the system’s energetic evolution, and thus the resultant mechanical behavior. The developed model reconciles experimental measurements of non-equilibrium grain boundaries in nanocrystalline metals without invoking free fitting parameters. Furthermore, these results provide a new perspective on kinetic pathways for achieving various interfacial states, and thereby facilitates previously inaccessible property regimes.
SPG-72: Mechanical Behavior of NiTi Shape Memory Alloy Thin Films: Ji-Young Kim1; Injong Oh1; Abdul Rehman1; Yu Hyun Park1; Wael Zaki2; Gi-Dong Sim1; 1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; 2Department of Mechanical Engineering, Khalifa University, Abu Dhabi, UAE
Shape memory alloy(SMA) is a material which shows unusual deformation depending on temperature or loading condition. Although a lot of research have focused on the bulk-scale mechanical properties of these alloys, it is still hard to apply SMAs in micron-scale applications such as electric or biomedical sensor. In this study, we conducted in-situ tensile test of NiTi, which is the one of the well-known SMAs, in order to investigate the small-scale mechanical behavior for small-scale applications. Here, we focused on the superelasticity effect at various loads. Tensile specimens are fabricated by sputter deposition and MEMS (Micro Electro Mechanical System) process. Tensile tests are conducted by using a customized in-situ SEM (Scanning Electron Microscope) tensile tester. For deeper understanding of the temperature-dependent superelasticity behavior of SMA thin films, we are currently working on high temperature mechanical testing, which is achieved by joule-heating of tungsten heaters co-fabricated with each specimen.
SPG-73: Mechanical, Electrical, and Structural Properties of Combinatorially Synthesized W-based Alloy Thin Films under Helium Irradiation: Haechan Jo1; Injun Oh1; Sanghun Park1; Euimin Cheong1; Daegun You1; Dongwoo Lee1; 1Sungkyunkwan University
Tungsten is one of the promising candidates for the plasma facing material (PFM) in fusion reactors as the material has a high melting point, high thermal conductivity, and low sputtering rate. When tungsten is exposed to He-ion irradiation, however, the microstructure and physical properties degrade, limiting its practical application as a PFM. It has been suggested that the use of fine microstructures and alloying W with other additives make the material irradiation damage tolerant. In the present work, we synthesized combinatorial binary alloy thin films of W-Ta and W-Re systems and carried out X-ray diffraction, transmission electron microscopy, nanoindentation, and 4-point measurement measurements to reveal the microstructure and composition dependence on the irradiation damages on physical properties. Type of damages depending upon microstructures and compositions will be characterized, and their effects on the mechanical and electrical properties will be shown.
SPG-74: Microstructural and Plastic Deformation Study of a TRIP Dual-phase High-entropy Alloy Fe50Mn30Co10Cr10: Monowar Hossain1; Nilesh Kumar1; 1University of Alabama, Tuscaloosa
The multicomponent alloys, also known as High Entropy Alloys (HEAs), have been the subject of intense exploration for over a decade now for a wide range of potential applications. To investigate microstructure – mechanical property correlation in a newly developed transformation-induced plasticity (TRIP) dual-phase high-entropy alloy (DP-HEA), Fe50Mn30Co10Cr10, microstructural analysis, mechanical testing, and fractography were performed on the DP-HEA using advanced microstructural and mechanical properties characterization tools including digital image correlation. A variation in the hardness values was observed possibly due to the presence of two different phases in the microstructure. The yield strength, ultimate tensile strength, and % elongation were estimated from tensile test results. The fractography of the fractured tensile specimens revealed ductile fracture of the alloy. The strain distribution, in the gage section, was found to be inhomogeneous probably due to differences in the deformation of crystals with different crystallographic orientations, phases, or both.
SPG-75: Negative Poisson’s Ratio in Heusler-type Cu-Al-Mn-based Shape Memory Alloys: Sheng Xu1; Ryota Tsukuda1; Mi Zhao1; Xiao Xu1; Toshihiro Omori1; Kyosuke Yoshimi1; Ryosuke Kainuma1; 1Tohoku University
A negative Poisson's ratio refers to the phenomenon of materials expanding along the transverse direction upon uniaxial tension or compression. In this study, the Poisson’s ratio was investigated in Heusler-type Cu-Al-Mn-based shape memory alloys. In a Cu-16.9Al-11.6Mn (at%) β-phase single crystal prepared by abnormal grain growth, when stretched along the vicinity of the [110] direction, the sample expands along the [1-10] direction, showing a negative Poisson's ratio of -0.51, while shrinking along the [001] direction with a large positive Poisson's ratio of 1.36. These experiment results agree well with the values calculated from the elastic constants and elastic anisotropy. Moreover, the negative Poisson’s ratio can also be obtained in polycrystalline Cu-Al-Mn-Ni sheet samples by texture control through optimized thermo-mechanical treatments. The negative Poisson’s ratio, together with the superelasticity, enables the Cu-Al-Mn-based shape memory alloys to be promising candidates for novel applications, such as multi-switch mechanical diodes.