Shalini Singh
Shalini completed her Undergraduate degree from B.Tech (Mechanical Engineering), AKGEC ,India, and Masters of Technology from IIT, Indore, India. She joined us in January, 2022 and is currently Visiting Scholar in our team.
My Work
My research interests are Customized Shape Memory Alloy (SMA) Structures using Wire Arc Additive Manufacturing and Laser Powder Based Fusion
Research Summary
Shape memory alloys (SMA) are of significant scientific interest for applications in a variety of fields, including damping systems, vibration control systems, MEMS devices, active layers in thin film actuators, and other applications. Due to numerous flaws, such as strong hysteresis and a reduction in life cycle, the usage of SMA in the form of bulk structures is relatively restricted. In this work SMA integrated bulk samples have been prepared with different Additive Manufacturing (AM) methods such as wire and powder based system. Developing SMA porous structures is of great interest due to their applicability towards biomedical implants and vibration dampers for civil structures, machineries and automobiles. There is lot of work on porous structure fabrication through powder based systems but there is no work on Wire Arc Additive Manufacturing for SMA integrated porous structure fabrication has been used which was very challenging due to weld pool instability ,heat accumulation effect, residual stress , spatter and distortion etc. In this work, laser hybrid system has been used for resolving the issues related to melt pool instability by reducing surface roughness of the surface roughness of substrate roughness (24 µm to 2.8 µm). With the help of laser marking track width can be minimize (2 mm) and along with geometry mechanical properties and shape recovery (up to 2.4 mm of displacement) will also enhanced. For higher heat accumulation effect, interpass temperature control (200⁰ C-400⁰ C) and interlayer delay (10s-30s) has been used will help in residual stress reduction oxidation reduction, and mechanical properties as well will increase due to Ni rich phases formation. Preheating has been also used which will change temperature gradient and reduces the stresses and also reduce cold crack probability. Along with the geometrical analysis, microstructural, structural, phase transformation, mechanical properties and shape recovery behavior have been also studied.
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