REU Site in Microengineered Materials Abhaya K Datye

REU Site in Microengineered Materials Abhaya K. Datye, University of New Mexico DMR 0354157 University of New Mexico Julia Szprengiel The Cooper Union for the Advancement of Science and Art Alicia Ayala/Ronald Loehman - mentors Oxidation-Resistant Coatings on Carbon-Carbon (C-C) Composites C-C composite Goal: To develop oxidation-resistant coatings on C-C composites so that they can be used in air at temperatures over 2000°C. Significance: Favorable properties of C-C composites such as their large strength-to-weight ratio, low thermal expansion coefficient, resistance to thermal shock, and ability to form complex shapes make them favorable for aerospace and thermonuclear fusion applications. Approach: The composition and flow of borosilicate, silica, and zirconia coatings, as well as the combination of these were studied. Thin film coatings were made in the lab, and applied either manually or by dip-coating (pictured) onto bulk graphite and C-C composites. SEM, x-ray diffraction, and TGA analysis were used to characterize the coatings. Bulk graphite Dip-coating a graphite sample Scratched borosilicate glass coatings on graphite substrates heal after heat treatment at 1300°C Results: – – Uniform zirconia and silica coatings were obtained. When scratched and heat treated, borosilicate, zirconia, and silica coatings proved to be self-healing. Results obtained from coatings on bulk graphite will be used to apply the coatings to C-C composites. Zirconia, silica, and borosilicate coatings are not oxidation resistant on their own, but can be combined with other coatings such as Zr. B 2 and Hf. B 2 to improve C-C composite oxidation resistance.

During the summer of 2004, 18 students from universities around the USA participated in the UNM REU program in Microengineered Materials. Of these, 14 were supported by the NSF REU site program, and 4 through other grants at UNM. The students did hands-on research, attended seminars, did field trips to and Sandia and Los Alamos National Labs and made a total of 3 research presentations attended by faculty and mentors. The student group was diverse with 8 women and 6 students from minority groups underrepresented in science and engineering.