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16 JUNE 2017 — PFonline.com Salt spray resistance testing was performed at the NASA KSC CTL and at ESA ESTEC. Only data from NASA testing is reported here. Test panels were subjected to a 5 percent NaCl salt spray, pH-adjusted to a range of 6.5 - 7.2, in accordance with ASTMB 117 (Standard Practice for Operating a Salt Spray [Fog] Apparatus). Test panels were inspected for the formation of corrosion every 168 hours. Test panels were evaluated for pitting and pit count was recorded weekly. Areas within 0.25-inch from edges, identifica- tion markings, and holding points during processing or salt spray exposure were excluded. Color loss was not cause for rejection. Results See results from salt spray testing in Table 3. In general, pretreatments did not perform well on 2024-T3 and 2024-T8 TABLE 2: NASA and ESA Test Procedures and Evaluation Criteria TEST TEST METHOD EVALUATION CRITERIA LOCATION Salt Spray Resistance ASTM B 117 MIL-DTL-5541 NASA KSC ESA ESTEC Humidity Testing * 50°C / 95% RH = 2,200 hours MIL-DTL-5541 ESA ESTEC 80°C / 95% RH = remainder of test Thermal Cycle Testing Modified ECSS Q ST 70 04C MIL-DTL-5541 ESA ESTEC * After 2,200 hrs., conditions were changed to 80°C / 95% RH, due to no visible corrosion effects on any alloy surface treatment combination. alloys except for 2024-T3 test panels pretreated with SurTec 650V. Overall, pretreatments performed better on 6061-T6, 7075-T6, and 7075-T73 alloys. SurTec 650V performed the best across the alloys and showed promise in protecting 2024-T3. The reason for the varied results per alloy is that resistance to corrosion decreases with increasing copper content. Alloy 2024 has a very high copper content (3.8 - 4.9 Wt. percent) making it difficult to protect from corrosion. Alloy 6061 has lower copper content (0.15 - 0.4) and resists corrosion even if no steps are taken to treat or coat the alloy. Another factor that can contribute to variances with pretreatment performance include the quality of the test panels. Test panels that have scratched and marred surfaces may contribute to reduced pretreatment performance. Parallel testing was performed at ESA with results published in its report, "Evaluation of Alternative Surface Treatments and Coating Systems as Future Replacements for Chromate based Conversation 4221 Courtney Road Franksville, WI 53126 USA Phone: 866-275-3774 • Fax: 866-329-3774 • sales@epsi.com • www.epsi.com EPSI MAKES IT EASY WITH INNOVATIVE SOLUTIONS THAT'S THE EPSI GUARANTEE 866-275-3774 • sales@epsi.com • www.epsi.com Increase Your Efficiency and Reduce Costs! 100% In-Stock Guarantee on High Usage Masking Products World-Class Line of Masking/Coating Tapes - MADE IN USA Fast Delivery! - We're Closer than You Think! Local, Dedicated Sales Representative Industry Leading Customer Service Best-in-Class Partner Programs Innovative Product Design and Development Initiatives Dedicated In-House R&D; Department Port-Tite™ Liqui-Tite™ PATENT NO. US D761,394 S AEROSPACE