Shape Memory Materials

Transcription

1 Shape Memory Materials Nicole Riccobono CHEM C150 APRIL 10 TH 2018

2 Shape Memory and braces Nickel Titanium based shape memory alloys Aka smart wire or memory wire

3 What are Shape Memory Materials? Shape Memory Effect: Material undergoes deformation and after a particular stimulus is applied it can return to the original shape. Materials Today,Volume 10, Issue 4, April 2007, Pages 20-28

4 History 1932 AuCd alloy shape memory affects reported in AuCd alloy 1940 s elastic memory Mather et al. First shape memory affects reported in a polymer 1962 NiTi alloy (Nitinol) Discovered at Naval Ordinance Laboratories by William Beuhler in coined Shape Memory Polymers by CDF Chimie Company (France)

5 Types of Shape Memory Materials Classification: Smart Materials Shape Memory Alloys Polymorphic May have two crystals or phases Shape memory effect involves phase transformations between them Super Elastic Effect From deformation between an austenitic and martensitic phase (solid-solid transformation) that is reversible. Shape Memory Polymers Actively Moving Polymers Viscoelasticity property of materials that exhibit both viscous and elastic characteristics when undergoing deformation Light Weight Generally Higher Recovery Strain

6 Types of Shape Memory Materials Classification: Smart Materials Shape Memory Alloys NiTi Alloy (Nitinol) Ni: 55.5 wt%, Ti: 44.5 wt% Cu-Zn-Al Alloys Cu-Zn-Ni Alloys Co-Ni-Al Fe-Mn-Si Shape Memory Polymers Aliphatic polyetherurethane (TFX) methylene bis(p-cyclohexyl isocyanate), butanediol, and polytetrahydrofuran Biodegradable Mulitblock copolymer (PDC) Polyester based SMP Polynorbornene based SMP

7 Theory Shape Memory Alloys Step 1: The Original Shape Heat above transformation temperature Step 2: Cooling Allow to cool to Martensite phase Diffusionless Orderly shift of large group of atoms Step 3: Deformation Step 4: Heat Treatment Phase Transformation from deformed Martensite to high ordered austenite phase. IE//Nitinol 1-hr Heat Treatment at 500 C Cycle can be repeated Materials Science and Engineering: an introduction, Wiley, Pg 395

8 Theory Shape Memory Alloys Mechanical twinning involves a shear of a specific magnitude which reorients a part of the parent into a mirror orientation Thermoelastic deformation: nonpermanent deformation when material is heated Temperature Memory Effect (TME) the previous temperature of interruption can be memorized and revealed in the next heating process

9 Theory: Shape Memory Polymers Programming and Recovery Cycle Netpoints determine the permanent shape of the polymer network Chemical and Physical Interactions Deformation Polymer is deformed and fixed into temporary shape Molecular Switches Target Netpoints Stimulus: heat, water, light, electrical current, magnetic field Materials Today,Volume 10, Issue 4, April 2007, Pages 20-28

10 Biomedical Applications Nitinol guidewires Stents Inferior Vena Cava Filters Materials Science and Engineering: A,Volume 378, Issues 1 2,2004,Pages 16-23

11 Applications Eye Glass Frames Golf Clubs Aerospace /01/21/bendable-eyeglasses/ html om/chevron-noise-reduction/

12 References: Callister, W. D.; Rethwisch, D. G. Materials science and engineering: an introduction, 9th ed.; Wiley: Hoboken, NJ, Marc Behl, Andreas Lendlein, Shape-memory polymers, Materials Today, Volume 10, Issue 4,2007, Pages 20-28, ISSN , N.B Morgan,Medical shape memory alloy applications the market and its products,materials Science and Engineering: A,Volume 378, Issues 1 2,2004,Pages 16-23,ISSN , ii/s ) Papadopoulos, P.; T. Duerig, NDC V. Imbeni, SRI Y. Jung, PU J.M. McNaney, LLNL R.O. Ritchie, UCB H.-R. Wenk, UCB. CONSTITUTIVE MODELING AND SIMULATION OF THE SUPERELASTIC EFFECT IN SHAPE-MEMORY ALLOYS. Department of Mechanical Engineering, University of California, Berkeley W.M. Huang, Z. Ding, C.C. Wang, J. Wei, Y. Zhao, H. Purnawali, Shape memory materials, Materials Today, Volume 13, Issues 7 8,2010, Pages 54-61,ISSN ,