Online Store: Popular On-demand Webinars
Main Storefront
        

Laser Surface Treatment of Structural Aerospace Composites

Item Options
Sign in for your pricing!
Price: $249.00
Quantity: *
 
Description

NASA Langley Research Center (LaRC) has been involved over the past decade in the development of laser ablation as a method to surface treat aerospace structural fiber reinforced composites (CFRPs) and metal alloys (Ti and Al based). Laser surface treatment has been shown to be a rapid, high precision, and reproducible method for surface treatment of these materials, and is amenable to automation. The laser ablation process removes surface contamination such as silicones, creates surface roughness, and chemically activates a surface for bonding. The degree of ablation is controllable by adjusting laser parameters. In the case of CFRPs, ablation can be performed without damage to any underlying carbon fibers. In the case of metal alloys, ablation is possible without surface embrittlement, heat damage or creation of undesirable grain structures or morphologies.

The optimum laser treatment conditions are substrate dependent and generally are influenced by laser wavelength and pulse duration (typically fixed for a laser system), and laser power. In the case of metal alloys such as Ti-6Al-4V, the laser ablation process eliminates the need for several steps of the conventional processes, including hydrofluoric (HF) acid and caustic treatment. These steps are often conducted in dip tanks and require costly facilities and environmentally unfriendly liquids. In addition, the laser can create nano-porosity on the Ti-6Al-4V alloy surface allowing for sol-gel penetration and thereby creating a gradient interface with improved temperature and mechanical performance. NASA LaRC has also been involved with the development of in-line characterization methods compatible with the laser treatment process to rapidly determine the presence of key contaminates such as silicones that, even at very low concentrations, are a threat to adhesive bonding.

A spectroscopic technique called laser induced breakdown spectroscopy (LIBS) has been developed to rapidly detect silicones at concentrations below those known to cause bonding problems. This technique requires no sample preparation, vacuum or inert atmosphere, has sensitivity comparable to XPS, and has no practical size limitations. This presentation will give an overview and update of these developments with specific examples highlighted. (51 minutes long)

 

Objectives:

  • Use of lasers for the purpose of preparing composite and metal alloys for adhesive bonding
  • Effect laser surface treatment has on the substrate material (chemistry and topography)
  • Use of laser induced breakdown spectroscopy (LIBS) to detect minute quantities of contaminants, primarily silicones, in real time with no sample preparation
  • How LIBS works and how it can be implemented with the laser surface treatment process

 

Expert Presenter:

 

John W. Connell, PhD, Senior Polymer Scientist - NASA Langley Research Center

John W. Connell is a senior scientist in the Advanced Materials and Processing Branch at the NASA Langley Research Center where he has worked for over 30 years. He received B.S. ('82 Chemistry) and Ph.D. ('86 Organic/Polymer Chemistry) degrees from Virginia Commonwealth University. He is the author of over 160 journal articles, 225 conference publications, and 53 U.S. Patents. He received the prestigious NASA Medals for Exceptional Scientific Achievement in 1997, Co-Inventor Commercial Invention of the Year for NASA in 2008, Exceptional Technology Achievement Medal in 2015 and Exceptional Service Medal in 2019. He is Editor-in-Chief of the Journal High Performance Polymers and a Fellow of both the Institute of Physics (IOP) and the Society for the Advancement of Material and Process Engineering (SAMPE). 

 
Membership Software Powered by YourMembership  ::  Legal