| Description |
x, 51 leaves : illustrations ; 29 cm |
| Summary |
"The alkaline cleaning solution temperature is identified as an important cleaning process parameter in spray deposition of cerium-based conversion coatings on aluminum alloy 2024-T3. The cleaning process removes contaminants and other impurities to improve the coating rate, adhesion of the coating/substrate interface, and salt fog performance of the alloy. The quality of the cleaning process impacts the ability to pass 14 days of salt fog exposure according to ASTM B117. The first paper reports the effects of varying the alkaline cleaning solution temperature on the coating thickness, and salt fog performance. The panels were cleaned for five minutes at 45°C, 55°C, and 65°C, and spray deposited to observe the effects of cleaning solution temperature on cerium oxide thickness. The 45°C, 55°C, and 65°C cleaned panels had cerium oxide layers of 100 nm, 143 nm, and 296 nm thick, respectively. The 55°C, and 65°C cleaned panels passed 14 days salt fog testing (ASTM B117). The second paper examines the formation of a cerium based conversion coating after 5, 10, and 15 spray cycles for panels cleaned with five minutes immersion in 45°C, 55°C, or 65°C alkaline cleaning solution. Observation during spray deposition revealed the panels required an incubation period of three to five spray cycles before a coating could form. The cerium oxide coating thickness increased after 10 and 15 spray cycles. The cerium oxide thickness after spray deposition was 90 nm, 440 nm, and 285 nm for panels cleaned at 45°C, 55°C, and 65°C, respectively. The best coating was the 65°C cleaned panel which had a more uniform and less severely cracked coating than the 55°C cleaned panel"--Abstract, leaf iv. |
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