“Laser-Interference Surface Preparation for Enhanced Coating Adhesion and Adhesive Joining of Multi-Materials" by Dr. Adrian Sabau

This project supports SERDP’s efforts to reduce Department of Defense’s use of chemical conversion coatings for corrosion protection, which usually employ highly toxic chromate solutions, often hexavalent chrome type-I by developing sustainable, cost-effective technologies. Developing and transitioning new non-chemical processes for surface preparation are sought to drastically reduce the environmental impact, risks and costs in the manufacture and maintenance of DoD weapons systems. The objective of this project is to understand and evaluate the feasibility of using a one-step process at ambient conditions based on laser-interference structuring techniques to replace the chemical conversion coating steps prior to the application of coating systems or adhesive bonding for Al and Ti aircraft components. The presentation described preliminary results for the surface preparation of Al2024-T3 for coating/adhesive bonding using laser-interference processing. The laser-interference power profile, which was used to structure the surfaces, was created by splitting the beam and guiding those beams to the sample surfaces. The results for the single-lap shear tests of an aluminum alloy and carbon fiber polymer composite specimens indicate an increased joint performance over baseline joints. Joints made with laser-structured surfaces were found to absorb approximately 150% more energy than the baseline joints.

“Laser Technology in Aerospace Maintenance" by Mr. Tom Naguy

The U.S. Air Force, with significant support from the Strategic Environmental Research and Development Office (SERDP) and the Environmental Security Technology Certification Program (ESTCP), has been investigating and implementing the use of laser technology in support of maintenance operations for many years, specifically in the areas of depainting and surface preparation of materials. Cost and environmental and occupational health savings in the use of laser technology over chemical or physical methods have been well documented. Laser depaint technology of late has focused on fiber delivered lasers but CO₂ laser technology has advances that should not be overlooked and efforts on this technology are underway.

Implementation of Hand Held laser technology is underway across USAF bases in the states as well as overseas. Large off-aircraft components such as aircraft radomes have been successfully laser de-painted for many years and we are looking to expand this capability to other depots. Full aircraft depaint for the F-16 is in the final stages of full production implementation. SERDP and ESTCP are key partners in expanding the use of lasers and investigating new lasers to improve corrosion, fatigue and adhesion performance.

Speaker Biographies

Dr. Adrian Sabau is a Senior Research Staff Member of Oak Ridge National Laboratory in the Materials Science and Technology Division. Adrian seeks to advance the laser processing, photonic processing, materials processing, and materials for energy applications through the development of computational and experimental techniques. Most recently, Adrian pioneered the use of laser-interference processing for multi-material joining applications. He is the recipient of two R&D 100 awards in process sciences and has published more than 130 technical papers. Adrian received an Engineer Diploma in Mechanical and Materials Processing from the University of Craiova, Romania and doctorate degree in Mechanical Engineering from Southern Methodist University in 1996.

Mr. Tom Naguy is currently the Deputy Technical Director for Air Force Materiel Command (AFMC)'s Logistics and Sustainment Directorate at Wright Patterson Air Force Base in Ohio. In this position, Tom develops life cycle product support policy and enterprise sustaining engineering policy for Air Force weapon systems. His areas of responsibilities include transitioning and implementing technologies to reduce and eliminate the use of hazardous materials in weapon systems. In addition, he is a key member of the Air Force’s Additive Manufacturing implementation program. Tom has extensive expertise with materials and process engineering, specifically in the areas of coatings, laser depainting, and corrosion technologies. Tom also serves on the AFMC Energy and Environmental executive committees. He is a member of the DoD Joint Technology Exchange Group and the SERDP and ESTCP Committees for Weapon Systems and Platforms. Prior to this current assignment, he was the Program Manager for the Environmental and Energy Program and the Advanced Power Technology Office at the Air Force Research Laboratory. Tom earned Bachelor’s and Master’s degrees in chemical engineering. His professional military education includes the Air War College, National Defense University's National Security Course, Air Command and Staff College, and Squadron Officer School.