ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
SiO2 coatings and double layer films of SiO2/Si3N4 have been designed and prepared onsapphire (α-Al2O3) by radio frequency magnetron reactive sputtering in order to improve the opticaland mechanical properties of infrared windows of sapphire. The transmission of the coated anduncoated sapphire in the wavelength range from 2.5 to 6.7um was determined. Surface morphologyand roughness of coated and uncoated sapphire have been measured using a talysurf. The flexurestrength of coated and uncoated sapphire samples has been studied by 3-point bending tests at roomtemperature and high temperatures. The results show that the coatings can improve the surfacemorphology and reduce the surface roughness of sapphire substrate. What’s more, the designed singlelayer of SiO2 film and two-layer of SiO2/Si3N4 films can both increase the transmission of sapphire inmid-wave IR and strengthen sapphire at high temperatures. Coated sapphire transmits over 95% atwavelength from 3 to 5um for the two designs. Flexure tests reveal that SiO2 coatings and SiO2/Si3N4films increase the strength of c-axis sapphire by a factor of about 1.5 and 1.4, respectively, at 800ºC
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.26-28.619.pdf
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