NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  CONTENTS OF PRESENTATION Introduction Novel NiTi Films 1.One Dimensional NiTi Films 2.Gradated NiTi Films 3.NiTi (Ms1)/NiTi(Ms2) Films

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Corrugated Films - Complicated Stress Distribution Report on ”Corrugated ” Film that can be easily analyzed

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Gradated Films - Not Easy to Prepare Report on Gradated Films prepared by varying substrate temperature

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Report on “Corrugated “ Films that can be easily analyzed

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  “Geometrically Novel” NiTi Films

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax 

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Principle of measurement, the cantilever deflection is determined from the change of the resonance frequency,

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Deflection of four differently patterned NiTi/Si bimorph cantilevers as a function of temperature. All bimorphs were processed simultaneously and identically. aspect ratio = 0.31 aspect ratio = 0.16    aspect ratio =    aspect ratio =

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Stress analysis of a 1-D / 2-D composite: (a) unstressed components (b) components stressed biaxially (c) patterned film and substrate stressed uniaxially.

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Conceptual martensitic microstructure: biaxially, top, and uniaxially, bottom,stressed SMA films in the two phase temperature region. The light and dark sections represent martensite and austenite, respectively.

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Cantilever deflection, Stoney’s Eq.: Martensite biaxial Martensite uniaxial Thermal  T

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Evaluation of slopes of deflection and comparison of ratios.

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Report on Structurally Gradated Films prepared by varying substrate temperature

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Martensite/Martensite Composite NiTi Films Previous Experiments Show: The nature of the martensitic transformation depends on the deposition temperature. Therefore: It is possible to create martensite/martensite composites by varying the substrate temperature during deposition.

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  semi-continuous discontinuous continuous t [min] T[ o C] 10 Variation of the substrate temperature during sputter deposition of the films. top, semi-continuous, center, discontinuous, bottom, continuous

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Internal Friction of NiTi double layer film Deposited while semi- continuously cooling,  ; Single layers deposited at 250 deg C,  385 deg C,

+ Manfred Wuttig  Tel  Fax  Natural and Artificial Multiferroics New UMD-based MURI SMA/SMA Composite With Large Damping !SMAs display large damping, up to 50%, at large amplitudes of vibration, useful for mitigation of earth quake damage ! -scale R-M SMA Composites display 11% damping at small amplitudes, useful for mitigation of (small amplitude) mechanical noise Craciunescu/Wuttig, J. Thin Solid Films R hombohedral Phase M onoclinic Phase -Scale R-M Composite = Temperature [C] Damping Q -1 [%]

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Analysis of Enhanced Damping

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Displacement curves of the NiTi double layer films; Depositions on cooling; semi-continuous,  discontinuous,  continuous. Depositions on heating; semi-continuous,  discontinuous, continuous.

Modulus curves for the double layer film deposited on cooling and heating left, cooling: semi-continuous,  discontinuous,  continuous right, heating: semi-continuous,  discontinuous, continuous NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax 

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  No Modulus Defect

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Large Displacement Large Damping

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  SUMMARY Two Kinds of Novel NiTi Films: 1.1-D Films; large displacement 2.Martensite/Martensite Films; large displacement large damping

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  COLLABORATORS Kiyotaka Mori Grad. Student Panasonic Res./Boston Corneliu Craciunescu Research Associate, U. Timisoara Supported by Office of Naval Research National Science Foundation

NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig  Tel  Fax  Ehemaliger Dresdner, Anhänger des damaligen DSC: mehrmaliger Deutscher Meister, Heimat-mannschaft von Helmut Schön, des Trainers der Deutschen Fussballmannschaft.