The School of Mechanical and Materials Engineering Seminar Series, “Understanding the Fatigue Debit Associated with Laser Ablation of High Strength Shipbuilding Steel: Linking Surface Modification to Fatigue Performance” Presented by Dr. Michael R. Maughan
About the event
Understanding the Fatigue Debit Associated with Laser Ablation of High Strength Shipbuilding Steel: Linking Surface Modification to Fatigue Performance
Presented by Dr. Michael R. Maughan, Associate Professor, Department of Mechanical Engineering, University of Idaho
Abstract:
Laser ablation is being actively considered as an alternative to conventional grit blasting for coating removal and surface preparation in naval applications because it can reduce secondary waste, improve process control, and mitigate worker exposure to hazardous materials. Despite these advantages, previous studies have reported inconsistent effects of laser ablation on the fatigue performance of high-strength steels, creating uncertainty regarding its implementation on fatigue-critical structures.
This presentation investigates the influence of pulsed laser ablation on the fatigue behavior of high strength shipbuilding steel and identifies the surface modifications responsible for observed performance changes. Axial fatigue testing revealed a reduction in fatigue life for laser-ablated specimens relative to grit-blasted controls. To determine the underlying mechanisms, laser-treated surfaces were characterized using optical microscopy, scanning electron microscopy, surface roughness measurements, hardness testing, and nanoindentation. The results show that laser processing produces localized melting and resolidification features, increases surface roughness severity, and introduces small crack-like defects that can serve as fatigue crack initiation sites. Mechanical property measurements indicate that these changes are largely confined to a thin near-surface layer, while the bulk microstructure remains unaffected.
The combined experimental evidence suggests that the fatigue debit associated with laser ablation is driven primarily by surface-condition effects rather than by significant changes to the underlying material. These findings improve understanding of laser-material interactions in naval steels and provide guidance for developing laser ablation process parameters and qualification procedures that preserve structural integrity while realizing the operational benefits of laser-based surface preparation.
Biography:
Dr. Michael R. Maughan is an Associate Professor of Mechanical Engineering at the University of Idaho, where he earned tenure in 2023. He holds B.S. and M.S. degrees in Mechanical Engineering from Idaho and a Ph.D. in Materials Engineering from Purdue University. Before joining academia, he worked as a mechanical design engineer at Hewlett Packard and IVUS Industries, and he holds five U.S. utility patents. He is a licensed Professional Engineer in Idaho and Washington.
His research links material behavior and microstructure to advanced manufacturing, with a current focus on bio-based thermoset composites for construction-scale 3D printing. He leads the NSF-funded PrinTimber project, has authored 37 refereed journal articles, and has served as major professor for 15 graduate students. He co-teaches the senior capstone design sequence and received the College of Engineering’s Outstanding Mid-Career Faculty Award in 2025.