국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Laser Ablation Surface Preparation of Ti-6A1-4V for Adhesive Bonding
저자	Palmieri, Frank L.;; Watson, Kent A.;; Morales, Guillermo;; Williams, Thomas;; Hicks, Robert;; Wohl, Christopher J.;; Hopkins, John W.;; Connell, John W.
Keyword	ADHESIVE BONDING;; ALUMINUM ALLOYS;; FAILURE MODES;; FLUORESCENCE;; LASER ABLATION;; PHOTOELECTRON SPECTROSCOPY;; PIXELS;; SHEAR STRENGTH;; SURFACE PROPERTIES;; SURFACE TREATMENT;; TITANIUM ALLOYS;; VANADIUM ALLOYS;; X RAY SPECTROSCOPY
URL	http://hdl.handle.net/2060/20120009343
보고서번호	NF1676L-13483
발행년도	2012
출처	NTRS (NASA Technical Report Server)
ABSTRACT	Adhesive bonding offers many advantages over mechanical fastening, but requires certification before it can be incorporated in primary structures for commercial aviation without disbond-arrestment features or redundant load paths. Surface preparation is widely recognized as the key step to producing robust and predictable bonds. Laser ablation imparts both topographical and chemical changes to a surface which can lead to increased bond durability. A laser based process provides an alternative to chemical-dip, manual abrasion and grit blast treatments which are expensive, hazardous, polluting, and less precise. This report documents preliminary testing of a surface preparation technique using laser ablation as a replacement for the chemical etch and abrasive processes currently applied to Ti-6Al-4V alloy adherends. Failure mode, surface roughness, and chemical makeup were analyzed using fluorescence enhanced visualization, microscopy, and X-ray photoelectron spectroscopy, respectively. Single lap shear tests were conducted on bonded and aged specimens to observe bond strength retention and failure mode. Some promising results showed increasing strength and durability of lap shear specimens as laser ablation coverage area and beam intensity increased. Chemical analyses showed trends for surface chemical species which correlated with improved bond strength and durability. Combined, these results suggest that laser ablation is a viable process for inclusion with or/and replacement of one or more currently used titanium surface treatments. On-going work will focus on additional mechanical tests to further demonstrate improved bond durability.