Concept:Adhesive joint strength depends on intimate microscopic contact (wetting) and mechanical keying between the liquid adhesive and the substrate surface.
Formula / Reaction:$$\text{Work of Adhesion: } W_A = \gamma_{S} + \gamma_{L} - \gamma_{SL}$$
Solution:- Degreasing removes low-surface-energy contaminants (oils, oxides) that prevent spontaneous wetting.
- Roughening increases the effective surface area and creates micro-cavities that facilitate mechanical interlocking upon curing.
Why other options are incorrect:- Option B: Surface cleaning does not alter the fundamental chemical polymerization kinetics of the adhesive formulation.
- Option C: Joint geometry and bondline thickness determine adhesive quantity, not cleaning.
- Option D: Surface preparation does not alter intrinsic bulk physical constants like thermal expansion coefficients.
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