Modeling of Selective Area Laser Deposition Vapor Infiltration (SALDVI) of Silicon Carbide

Selective Area Laser Deposition Vapor Infiltration (SALDVI) is a developing solid freeform fabrication (SFF) technique in which porous layers of powder are densified by infiltrating the pore spaces with solid material deposited from a gas precursor during laser heating. A 3D finite element model was developed that simulates SALDVI of silicon carbide. The model predicts the laser input power and the distribution of vapor deposited SiC within the powder bed as well as on the surface of the powder bed (SALD). The model considers a moving Gaussian distribution laser beam, temperatureand porous-dependent thermal conductivity, specific heat and temperature-dependent deposition rate. Furthermore, the model also includes closed-loop control of the laser power to achieve a desired target processing temperature on the top surface of the power bed. The simulation results agree fairly well with experimental data for simple geometries and offer guidelines for further experimental studies of the SALDVI process.