Graduate Student Seminar

November 14, 2025

12:45 p.m. ET

7500 Wean Hall

Hydrogen Environment-Assisted Cracking of Binder Jet Printed 17-4PH Stainless Steel

In this study, the hydrogen environment-assisted cracking (HEAC) behavior of additively manufactured (AM) 17-4PH stainless steel fabricated via binder jet printing (BJP) is assessed through fracture mechanics-based testing conducted in representative marine environments. Results are compared to analogous data generated for similarly heat-treated 17-4PH manufactured via conventional means (CM) as well as laser powder bed fusion (LPBF), which reveal key differences in HEAC susceptibility amongst the tested materials. These HEAC data are then coupled with hydrogen-metal interaction parameter measurements and microstructural observations for each alloy to understand the origins of the observed differences in HEAC susceptibility. Critically, this study reveals that AM-specific features, such as small-scale gas porosity, strongly impact HEAC behavior, which is mechanistically explained using an existing model for HEAC. The implications of these findings on the broader AM community are then discussed.

Zachary HarrisZachary Harris, Assistant Professor, Department of Mechanical Engineering and Materials Science
University of Pittsburgh

Harris leads the Environmental Fatigue and Fracture Laboratory with research focused on developing mechanistic understanding of the factors governing environment-induced degradation in the fatigue, fracture, and mechanical behavior of structural metals. Prior to Pitt, Prof. Harris was a Research Scientist within the Center for Electrochemical Science and Engineering at the University of Virginia, where he also received his Ph.D. in Materials Science and Engineering.

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