Dept. of Materials Science and Engineering

Slides:

Advertisements

Similar presentations

Graeme Ackland March 2010 Elasticity and Plasticity Graeme Ackland University of Edinburgh.

Advertisements

8-6 Compound Interest and Exponential Growth

Physical Metallurgy 17 th Lecture MS&E 410 D.Ast DRAFT UNFINISHED !!!

Thermoelastic properties of ferropericlase R. Wentzcovitch Dept. of Chemical Engineering and Materials Science, Minnesota Supercomputing Institute J. F.

Applications of Shape Memory Alloys to MEMS MAE 268 Greg Jarmer and Garrett Uyema.

Computational Solid State Physics 計算物性学特論第２回 2.Interaction between atoms and the lattice properties of crystals.

Electronic structure and mechanism for martensitic transformation in in Co 2 NiGa Shape Memory Alloys. Computational and Experimental Design of Novel CoNiGa.

E 3 AEROSPACE ENGINEERING RESEARCH SHAPE MEMORY ALLOYS (SMA S ) ¡ E3 Teacher Summer Research Program Aerospace Engineering Texas A & M University By Moses.

8 th Jun SEM X International Congress X-Ray Microdiffraction on Diamond-shaped NiTi for Biomedical Applications Apurva Mehta SSRL/ SLAC, Stanford.

Retained Austenite in TRIP-Assisted Steels role of transformation plasticity China Steel.

Shape memory Topic 11.

MOLECULAR DYNAMICS SIMULATION OF STRESS INDUCED GRAIN BOUNDARY MIGRATION IN NICKEL Hao Zhang, Mikhail I. Mendelev, David J. Srolovitz Department of Mechanical.

Thermal properties from first principles with the use of the Free Energy Surface concept Dr inż. Paweł Scharoch Institute of Physics, Wroclaw University.

F Session V Phase transition. Effect of Coulomb in microscopic models M.Ison et al. PRC 2003 Z=62 Z=124 E Lennard Jones molecular dynamics lowering of.

Dimitris C.Lagoudas Shape Memory Alloy Research Team Aerospace Engineering Department Texas A&M University Intelligent Systems Laboratory An Introduction.

Shape Memory Alloy Cantilever Beam Mike Hilldoerfer Numerical Analysis for Engineers April 10, 2001.

Design of TRIP-Assisted Steels for Automobiles. Microstructure has been extensively studied Microstructure understood: most aspects can be calculated.

Compensation of residual stress in welds using phase transformation.

Introduction The properties and behavior of metals (and alloys) depend on their: Structure Processing history and Composition Engr 241.

Thermal Processing of Metal Alloys

I. Adlakha 1, K.N. Solanki 1, M.A. Tschopp 2 1 School for Engineering of Matter, Transport, and Energy Arizona State University

Projection exercises Stable age distribution and population growth rate Reproductive value of different ages Not all matrices yield a stable age distribution.

Pervaporative membrane filtration for subsurface irrigation Tom Bond 1 *, May N. Sule 1, Lindsay C. Todman 1, Michael R. Templeton 1 and Jonathan A. Brant.

Chapter Outline: Phase Diagrams

How to calculate the total amount of  phase (both eutectic and primary)? Fraction of  phase determined by application of the lever rule across the entire.

Chap.1. Phase and Phase Diagram Phase( 상 ): Any material system usually contains regions which exhibit same properties such as specific volume, composition.

Energetics and Structural Evolution of Ag Nanoclusters Rouholla Alizadegan (TAM) Weijie Huang (MSE) MSE 485 Atomic Scale Simulation.

Stress-Strain-Diffusion Interactions in Solids J. Svoboda 1 and F.D. Fischer 2 1 Institute of Physics of Materials, Brno, Czech Republic 2 Institute of.

Mechanical Properties of Carbide Free Bainitic Steel

ACKNOWLEDGMENTS This research was supported by the National Science Foundation of China (NSFC) under grants , , , the Specialized.

Phase Field Modeling of Interdiffusion Microstructures K. Wu, J. E. Morral and Y. Wang Department of Materials Science and Engineering The Ohio State University.

Molecular Dynamics Study of Solidification in the Aluminum-Silicon System Supervisor: Dr. Jeffrey J Hoyt Peyman Saidi Winter 2013.

Recap of 11/26/ /3.40J/22.71J Physical Metallurgy 12/03/2013 Intak Jeon Department of Materials Science and Engineering Massachusetts Institute.

Thermodynamics and Kinetics of Phase Transformations in Complex Non-Equilibrium Systems Origin of 3D Chessboard Structures: Theory and Modeling Armen G.

Jianwei Dong, J. Q. Xie, J. Lu, C. Adelmann, A. Ranjan, S. McKernan

A study of Thin Film Shape Memory Alloys By Rajlakshmi Purkayastha Metallurgical and Materials Science IIT Bombay.

Shape Memory Alloys Theresa Valentine ENMA490 Fall 2002.

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS Technical Seminar Report On “SHAPE MEMORY ALLOYS” under.

Presented by Gokul R 7th semester Mechanical

AMML Effect of rise, peak and fall characteristics of CZM in predicting fracture processes.

Journal: Write an exponential growth equation using the natural base with a horizontal asymptote of y=-2.

University of Adelaide -Cooperative Research Centre for Welded Structures CRC-WS Microstructures in (High Strength) Steel Welds.

Introduction to Materials Science, Chapter 7, Dislocations and strengthening mechanisms University of Virginia, Dept. of Materials Science and Engineering.

Chapter 10 Phase Transformations in Metals (2)

Molecular dynamics simulation of strongly coupled QCD plasmas Peter Hartmann 1 Molecular dynamics simulation of strongly coupled QCD plasmas Péter Hartmann.

Stefan Bringuier, Nick Swinteck, Venkateswara Rao Manga, Pierre Lucas, Pierre Deymier, Krishna Muralidharan Dept. of Materials Science and Engineering.

Quasiharmonic Thermodynamic Properties of Minerals Renata M. M. Wentzcovitch Department of Chemical Engineering and Materials Science Minnesota Supercomputer.

Metallurgy of steel When carbon in small quantities is added to iron, ‘Steel’ is obtained. The influence of carbon on mechanical properties of iron is.

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  CONTENTS OF PRESENTATION.

Post-perovskite Transition in MgSiO3

Molecular Dynamics Simulations and the Importance of

Modelling of the motion of phase interfaces; coupling of thermodynamics and kinetics John Ågren Dept of Materials Science and Engineering Royal Institute.

March 28, 2008 New Materials from Mathematics – Real and Imagined Richard James University of Minnesota Thanks: John Ball, Kaushik Bhattacharya, Jun Cui,

Kinetics of Structural Transformations in Metal and Ceramic Systems Microstructure in Decomposition of Metastable Ceramic Materials Armen G Khachaturyan,

Mechanisms and Modeling of High-Temperature Anisotropic Deformation of Single Crystal Superalloys Bhaskar S. Majumdar, New Mexico Institute of Mining and.

Twinning Studies via Experiments and DFT-Mesoscale Formulation Huseyin Sehitoglu, University of Illinois at Urbana-Champaign, DMR Twin Energy Barriers.

 Austenite - The name given to the FCC crystal structure of iron.  Ferrite - The name given to the BCC crystal structure of iron that can occur.

Decrease hysteresis for Shape Memory Alloys Jin Yang; Caltech MCE Grad

Simulation of Phase transformation behavior of NiTi doped with Cu during loading using classical molecular dynamics S. Aich, A. Behera and S. Ghosh Department.

Microstructure From Processing: Evaluation and Modelling Nucleation: Lecture 4 Martin Strangwood, Phase Transformations and Microstructural Modelling,

Materials, transformation temperatures & strength

Materials Science and Metallurgy Mathematical Crystallography

Prof. Sanjay. V. Khare Department of Physics and Astronomy,

Crystallography H. K. D. H. Bhadeshia Introduction and point groups

Thermodynamics of Phase Change from Solid to Liquid

CHANGES to ECOSYSTEMS and POPULATIONS

1 µm Surface 1 Surface 2 50 µm Srinivasan & Wayman, 1968.

Muhammad Istiaque Haider and Nathan Salowitz

upper bainite 1 µm lower bainite Surface 1 Surface 2 50 µm Srinivasan & Wayman, 1968.

Presentation transcript:

Dept. of Materials Science and Engineering Transformation-induced stress in austenite associated with shape memory effect in NiTi Sourav Gur, Venkateswara Rao Manga, Stefan Bringuier, Krishna Muralidharan, Frantziskonis George Dept. of Materials Science and Engineering University of Arizona

The induced tetragonal strain Tensor removes the phonon instability Quantified transformation-induced strain state of Austenite in the two-phase region The induced tetragonal strain Tensor removes the phonon instability Austenite in the two-phase region - The strain - Temperature dependence

NiTi: Austenite (B2)↔(B19’) Martensite phase transformation is displacive - Phonon instability Softening of TA phonons near zone boundaries - In two-phase (B2+B19’) region: Transformation stresses stabilize B2

On the nature of transformation-induced strain in Austenite εij(B2) strain superelasticity Characteristic internal strain tensor that makes B2 stable in two-phase region - shape memory effect - superelasticity Objectives: Using molecular dynamics simulations What is the internal strain state (i.e. strain tensor) of austenite in the two-phase region associated with the shape memory effect in NiTi? Temperature dependence of the strain?

B2-B19’ phase transformation as a function of temperature 250 K 330 K 370 K 450 K

B19’ phase fraction as a function of temperature Size-I : 25 Å X 25 Å X 200 Å Size-II: 50 Å X 50 Å X 200 Å Size-III: 75 Å X 75 Å X 200 Å Phase fractions from sufficiently large supercells

Martensite phase fraction as a function of temperature - Richards equation[Richards] – for growth of plant population - Zotov et al. used to describe the evolution of phase fractions [zotov et al] Tm --- temperature for maximum transformation rate g, v – dictate the transformation rate Zotov et al. Journal of alloys and compounds 616(2014)385 Richards J. Exp. Bot 10 (1959) 290

Strained lattice parameters of Austenite phase as a function of temperature Unstrained lattice parameter extrapolated (001) (010) (100) strained-B2 εin[100] = (a[100]-aunstrained)/aunstrained In the two-phase region aunstrained of B2 is obtained by extrapolation

Measured principal strains on Austenite phase as a function of temperature (001) (010) (100) strained-B2 εin[010] = εin[100] Strain state of austenite in two-phase region : tetragonal strain εin[001] What equation based on phenomenology best describes the strain as function of T?

The relationship between Martensite fraction and the principal strains in Austenite Richard equation ?

Strain in austenite as a function of temperature The relationship between Martensite fraction and the principal strains in Austenite Martensite phase fraction with temperature [Zotov et al.] Martensite phase fraction with internal strain on austenite phase, in [100] or [010] direction: ε0= 0.0119 Strain in austenite as a function of temperature

Variation of strain in austenite as a function of temperature a1= -0.0198, b1=2.451 a2= -0.0370, b2=8.643

Phonon dispersion of austenite phase with and without lattice strain at 364 K Austenite at T=364 K with no strain Austenite at T=364 K with no calculated strains - In two-phase region (austenite + martensite): - the phonon instability dissappears due to the transformation induced strains/stress in austenite - The principal strains are quantified

Summary The transformation-induced strain state in austenite in the two-phase region associated with shape memory effect in NiTi is quantified Tetragonal-form strain tensor is found to stabilize the austenite The strain that removes the phonon instability is found to vary exponentially with temperature

Acknowledgment We thank Dr. Ting Zhu (Woodruff school of mechanical engineering at Georgia Institute of Technology) for the EAM potential

The Austenite (B2)↔(B19’)Martensite phase transformation is displacive - Phonon instability Softening of TA phonons near zone boundaries - In two-phase (B2+B19’) region: Transformation stresses stabilize B2 What is the internal-strain state (i.e. strain tensor) of austenite in the two-phase region associated with the shape memory effect? Is the strain tensor of a particular type over the entire range? εij(B2) strain superelasticity