NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Laser Surface Preparation of Epoxy Composites for Secondary Bonding: Optimization of Ablation DepthSurface preparation has been identified as one of the most critical aspects of attaining predictable and reliable adhesive bonds. Energetic processes such as laser ablation or plasma treatment are amenable to automation and are easily monitored and adjusted for controlled surface preparation. A laser ablation process was developed to accurately remove a targeted depth of resin, approximately 0.1 to 20 micrometers, from a carbon fiber reinforced epoxy composite surface while simultaneously changing surface chemistry and creating micro-roughness. This work demonstrates the application of this process to prepare composite surfaces for bonding without exposing or damaging fibers on the surface. Composite panels were prepared in an autoclave and had a resin layer approximately 10 micrometers thick above the fiber reinforcement. These composite panels were laser surface treated using several conditions, fabricated into bonded panels and hygrothermally aged. Bond performance of aged, experimental specimens was compared with grit blast surface treated specimens using a modified double cantilever beam test that enabled accelerated saturation of the specimen with water. Comparison of bonded specimens will be used to determine how ablation depth may affect average fracture energies and failure modes.
Document ID
20160005971
Document Type
Conference Paper
Authors
Palmieri, Frank L.
(NASA Langley Research Center Hampton, VA, United States)
Hopkins, John
(NASA Langley Research Center Hampton, VA, United States)
Wohl, Christopher J.
(NASA Langley Research Center Hampton, VA, United States)
Lin, Yi
(National Inst. of Aerospace Hampton, VA, United States)
Connell, John W.
(NASA Langley Research Center Hampton, VA, United States)
Belcher, Marcus A.
(Boeing Co. Seattle, WA, United States)
Blohowiak, Kay Y.
(Boeing Co. Seattle, WA, United States)
Date Acquired
May 9, 2016
Publication Date
May 18, 2015
Subject Category
Composite Materials
Report/Patent Number
NF1676L-19830
Meeting Information
SAMPE Baltimore Conference and Exhibition(Baltimore, MD)
Funding Number(s)
WBS: WBS 544163.04.03.07.02
Distribution Limits
Public
Copyright
Public Use Permitted.

Available Downloads

NameType 20160005971.pdf STI
No Preview Available