2. ASTM Scrape Adhesion Testing Results for the Three Different Thickness Variations of Si-PEI and UFG/PEI Coatings on AA 7075 Substrates As-Cast and after Corrosion Exposure to 3.5 wt % Aqueous Solutions of NaCl for 100 Days, Thermal 3.5 wt % Brine Solutions at 70 °C for 30 Days, and ASTM B-117 Salt-Fog Testing for 30 Days.

test/sample	ASTM D2197-13 (scrape test)
PEI
4–7 μm as-cast	>10.0 kg
4–7 μm post 100 day	8.60 kg
4–7 μm post thermal	6.30 kg
4–7 μm post salt-fog	6.40 kg
11–16 μm as-cast	>10.0 kg
11–16 μm post 100 day	9.20 kg
11–16 μm post thermal	7.20 kg
11–16 μm post salt-fog	7.20 kg
20–30 μm as-cast	>10.0 kg
20–30 μm post 100 day	>10.0 kg
20–30 μm post thermal	9.50 kg
20–30 μm post salt-fog	>10.0 kg
Si-PEI
4–7 μm as-cast	4.25 kg
4–7 μm post 100 day	4.05 kg
4–7 μm post thermal	6.00 kg
4–7 μm post salt-fog	4.05 kg
11–16 μm as-cast	5.85 kg
11–16 μm post 100 day	5.95 kg
11–16 μm post thermal	7.55 kg
11–16 μm post salt-fog	6.10 kg
20–30 μm as-cast	8.55 kg
20–30 μm post 100 day	7.55 kg
20–30 μm post thermal	7.70 kg
20–30 μm post salt-fog	6.50 kg
UFG/PEI
4–7 μm as-cast	7.50 kg
4–7 μm post 100 day	6.05 kg
4–7 μm post thermal	7.80 kg
4–7 μm post salt-fog	7.00 kg
11–16 μm as-cast	>10.0 kg
11–16 μm post 100 day	8.00 kg
11–16 μm post thermal	8.70 kg
11–16 μm post salt-fog	7.80 kg
20–30 μm as-cast	>10.0 kg
20–30 μm post 100 day	>10.0 kg
20–30 μm post thermal	>10.0 kg
20–30 μm post salt-fog	>10.0 kg