October meeting of MN Chapter of ASM International
Presented by Dr. Shivram Sridhar
Principal Scientist – Global Technology and Innovation at Medtronic
710 Medtronic Parkway, Mailstop LT220 | Fridley, MN 55432 | USA
Office 763.505.1113
Abstract
This seminar examines the mechanical behavior of Nitinol (NiTi) in cardiovascular devices, with
emphasis on the phase transformations that enable superelasticity and large recoverable
strains. It considers the demands of catheter crimping, deployment, and repeated physiological
loading, and the need for reliable methods to predict device stresses, strains, and fatigue
performance. The presentation explores experimental characterization methods, including
mechanical testing, differential scanning calorimetry, and optical and scanning electron
microscopy–based digital image correlation to measure local deformation. It discusses how
these measurements support finite element model calibration and validation, capturing
temperature-dependent behavior, tension–compression asymmetry, and strain localization, with
applications to cyclic loading of stent structures. Finally, the seminar examines how
thermomechanical processing shapes crystallographic texture and compares micromechanical
modeling approaches to explain its influence on Nitinol’s stress–strain response.
About the Speaker
Dr. Shivram Kashyap Sridhar is a Principal Scientist in Global Technology & Innovation at
Medtronic, based in Minneapolis, Minnesota. He earned his Bachelor of Technology in
Metallurgy and Materials Engineering from IIT Madras, India and his Ph.D. in Materials Science
and Engineering from Carnegie Mellon University. His work focuses on understanding how
materials microstructure influences performance, employing mechanical testing, microscopy,
and finite element analysis to solve challenges ranging from fundamental materials research to
medical device failure analysis and next generation device design. He will share insights into
the mechanical behavior of Nitinol (Nickel Titanium shape memory alloys) used in
cardiovascular devices.
Meeting at Davanni’s Pizza, 3015 Harbor Lane N, Plymouth, MN, October 15, 2026, 5:00-7:30pm
Just west of I-494 and Hwy 55 off Fernbrook and Harbor Lane.
Registrations available until 5 pm, October 13, 2026. Register here
Cost for Dinner:
ASM Members – $25
non-ASM Members – $35
Students – $0