Spray drying as a one-step production method of SiC-based granulates for direct reactive laser sintering of Reaction Bonded Silicon Carbide (RBSiC)

Abstract

This research is focused on the development and production of SiC-based granulates for reactive laser sintering. Ceramic slurries with different compositions of SiC, Si, C powders, and PVA binder were subjected to spray drying. Carbon source in form of latex was proposed to avoid a reaction of Si with H2O in alkalic pH caused by the presence of carbon in the slurry. It was observed that the latex was beneficial for improvement of the flowability. Selected granulates were subjected to laser processing using two different methods. The first one where SiC-based granulates were spray deposited on a SiC substrate and laser treated with single pulse working of the laser. The second method where a pressed green sample of SiC were processed by the continuous working mode of the laser. Results revealed that the use of the continuous work mode during laser processing allowed to produce Reaction Sintered SiC (RBSiC).

Keywords

• Reaction bonded silicon carbide
• Spray drying
• Laser processing
• Granulation
• Powder characterization