Seminar Speaker: Peeyush Nandwana, ORNL

Phase Transformations in Metal Additive Manufacturing

Abstract

Additive manufacturing (AM), colloquially known as 3D printing, has revolutionized the way we design components by enabling the fabrication of intricate geometric features. Features such as complex conformal cooling channels in tools and dies to improve their efficiency cannot be made via conventional manufacturing processes. While there are numerous alloys available for conventional manufacturing, there are only a handful of alloys that have been studied for AM. Repeated melting and extreme thermal gradients influence the phase transformation pathways in ways that limit the selection of alloys. For example, an alloy suitable for AM should have resistance to solidification cracking that occurs during liquid-solid phase transformation but should also be able to accommodate residuals that result from solid-state transformations. The metastable phase transformations can enhance some material properties while having the opposite impact on others and are highly dependent on the alloy chemistry. This talk will focus on some of the common phase transformations that are encountered during AM and their impacts on resulting microstructures.

Biography

Dr. Peeyush Nandwana is the Group Leader for the Materials for Advanced Manufacturing Group in the Materials Science and Technology Division at Oak Ridge National Laboratory (ORNL). He obtained his Ph.D. from the Department of Materials Science and Engineering at the University of North Texas in 2013 following which he joined ORNL as a postdoctoral researcher in 2014. In the last 10 years, he has worked on different additive manufacturing technologies with a focus on understanding and tailoring the underlying phase transformations. Outside of work, Dr. Nandwana is an avid tennis player and enjoys traveling.