Titanium substrates coated with silicate/zirconate sol-gel and plasma sputtered chromium have been adhered using a combined PETI-5 polyimide psuedo-thermoplastic primer/adhesive system. Composite laminates were exposed to thermal aging up to 2000 hours at 194 degreesC and subsequently nanoindentation testing was performed across each interface to determine material modulus degradation and plastic deformation changes. The procedure to analyze complex interfaces using nanoindentation are explained in detail including experimental set-up, analysis, and imaging; for example, inhomogeneities at the interface mandated that both low loads (as low as 25 muN) and a 90 degrees cube-corner diamond tip be utilized to obtain sub-micron resolution. Thermal aging resulted in an increase in PETI-5 primer and adhesive modulus by 15% and upwards of 30%, respectively, and the sol-gel modulus increased by approximately 10%. An exposure level at 1000 hours showed a 20% increase in the chromium modulus. Large increases in plastic deformation were observed in the polymeric materials likely due to chain embrittlement.