Investigation of the Environmental Effect on Adhesive Bonds

Adhesively bonded joints are increasingly being used in joining various
structural components in a variety of industries (Marine, aerospace, automotive, etc.).
Adequate understanding of the behavior of adhesively bonded joints under the
environmental effects is necessary to ensure efficiency, safety and reliability of such
joints. Therefore, the aim of this project is to investigate the degradation of adhesive
bonded joints dueto the environmental effects on a single lapjoint, whichconsists of
two adherent joint together by an adhesive, and it is widely used for producing insitu
shear strength data on adhesively bondedjoints tests. The materials used in this
project for suchtests are Aluminum and steel sheet as adherent, while Devcon epoxy
and Rill super glue are used as adhesive, they are specially formulated for use on
metals and other materials. Two sets of specimens and joints will be fabricated as
recommended by ASTMD1002andtested for shear strength; a set of specimens will
be tested for shear strength under normal conditions, while the second set of jointed
specimens will undergo corrosive environment (salt spray) then be tested for shear
strength. The results obtained from the experimental tests, will be used to analyze
and compare the variation on the joints strength under normal and corrosive
environment. The average shear strength of aluminum sheets bonded with Devcon
epoxy under normal and corrosive conditions is 16.43 MPa and 10.54 MPa
respectively, while aluminum bonded with Rill super glue under normal and
corrosive environment is 12.50 MPa and 4.54 MPa respectively; steel sheets bonded
with Devconepoxy presented 14.66MPa and 6.19MPa of joint strength under normal
and corrosive environment respectively, while bonded with Rill super glue, the
strength is found to be 18.01MPa and 13.38MPa under normal and corrosive
environment respectively. Therefore, it can be concluded that using aluminum as
adherent, best results are obtained when bonded together with Devcon epoxy, while
using Steel as adherent, best results are obtained when bonded with Rill super glue.
Further studies on more different types of adhesives will need to be done to provide
better alternative for adhesives selection with respect to the working environment.