Strain induced transformations and additive manufacturing - A pathway to develop multiphase materials

Strain induced phase transformations have been used for more than a century to improve the performance of  structural materials. This presentation will focus on how basic alloy design theory developed in the 70’s when combined with with the site specific nature of additive manufacturing (AM) can be used to accelerate development of radically new materials that were not possible using conventional manufacturing.  Here we leverage the site specific nature of AM to fabricate multiphase materials with engineered interfaces to trigger a martensitic transformation on loading. In situ and ex situ characterization shows that it is possible to engineer the interfaces at micro scale to trigger strain induced martensitic transformations resulting in enhanced strength and ductility of structural steels. The work demonstrates that additive manufacturing could be used for developing new classes of multi phase materials with superior mechanical properties.

Dr. Niyanth Sridharan

Oak Ridge National Laboratory

P.O. Box 2008

Oak Ridge, TN 37831

USA