Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS Technical Seminar Report On “SHAPE MEMORY ALLOYS” under the guidance of Mr. VIVEK SHARMA submitted by PRIYANKA MISHRA EI

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS INTRODUCTION  Shape memory alloys are metals that “remember” their original shapes.  Key characteristic - Martensitic phase transformation SHAPE MEMORY ALLOYS  The two unique properties shape memory effect pseudo-elasticity

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS Martensitic transformation  Deformation of the crystal lattice  Diffusion less Process

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS Shape Memory Effect  The transformation begins in the absence of stress, at a temperature M 0s  The transformation continues as the temperature is lowered until a temperature M 0f  The reverse transformation begins at the temperature A 0s and at the temperature A 0f the material is fully austenite

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS Pseudo-elasticity  pseudo-elasticity occurs without a change in temperature  Transformation occurs upon loading and unloading  Rubber like effect

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS STRESS-TEMPERATURE RELATIONSHIP  Stress plays an important role in the Transformation  An applied stress increases the Transformation Temp TRANSFORMATION TEMPERATURES  The temperature at which the material transforms from Martensite to Austenite is controlled by alloy composition

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS DEFORMATION OF MARTENSITE AND RECOVERY TO AUSTENITE

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS TRAINING OF SMA  The wire is hot/cold worked when it is in the Martensite phase  The wire is then heated to A f to recover its shape.  The wire is then cooled to martensite.  Effect-The solid exhibits two stable shapes

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS  BONE PLATES  DENTAL AND ORTHODONTIC APPLICATIONS  STENT APPLICATIONS

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS ADVANTAGES AND DISADVANTAGES OF SHAPE MEMORY ALLOYS  ADVANTAGES Bio-compatibility Diverse field of application Good mechanical properties  DISADVANTAGES Expensive Poor fatigue properties

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS CONCLUSION  A shape memory effect can undergo plastic deformation, and then be triggered into returning to its original shape  Led to a proliferation of diverse application

Technical Seminar Presentation 2004 Presented by - PRIYANKA MISHRA EI SHAPE MEMORY ALLOYS THANK YOU !!!