Performance of 3C-SiC thin films as protective coatings for silicon-micromachined atomizers

This paper presents a study of the deposition and performance of SC-silicon carbide (3C-SiC) coatings on the flow surfaces of silicon micromachined fuel atomizers. Atmospheric pressure chemical vapor deposition (APCVD) was used to grow 3C-SiC on atomizer features which were fabricated from silicon wafers using deep reactive ion etching (DRIE). The 3C-SiC films were shown to be conformal across high-aspect-ratio atomizer structures which were etched to depths greater than 250 mu m. For tests conducted at pressures up to 690 kPa, the SiC-coated atomizers had wider spray angles, equivalent Sauter Mean Diameters (SMD), and an 11% increase in flow rates when compared to uncoated atomizers. Erosion tests proved that the SiC coating can dramatically increase the service life of silicon fuel atomizers. (C) 1998 Elsevier Science S.A.