FeCrAl sputtering technique to enhance pool boiling critical heat flux

This book contains detailed information on fabrication of FeCrAl layer on top of the metal substrate by DC sputtering. It was found that substrate temperature and sputtering time affected the surface characteristics of the FeCrAl-layered heaters. A substantial increase in surface roughness was realized in the substrate temperature range from 150 to 600 oC during DC sputtering. Extensive pool boiling critical heat flux (CHF) experiments confirmed effect of the FeCrAl layer on the thermal safety margin of the heaters. Substantial CHF enhancement was achieved for the first time with all types of FeCrAl-layered heaters. The enhanced CHF was attributed to an increase in the roughness factor at the micrometer scale. This, in turn, could have a desirable effect on shortening the rewetting interval with the FeCrAl-layered heaters. Systematic experiments related to the surface characteristics and high-speed bubble departure images were also presented.