Multiple material solid free-form fabrication by selective area laser deposition

Abstract

Selective Area Laser Deposition (SALD) is a gas phase Solid Free-Form Fabrication approach to the shaping of materials without part specific tooling. SALD uses a laser beam to create a localized heated zone on a substrate surrounded by a reactant gas. Within the localized heated zone, the reactant gas decomposes to produce a solid deposit. Repeated scanning of the beam in a defined pattern builds a three-dimensional shape. The laser-induced temperature distribution within the heated zone coupled with the chemical thermodynamics and kinetics of a reactant gas mixture are shown to give control of both composition and microstructure in ceramic composites. The process for control of composition and microstructure in SALD deposits is demonstrated for titanium oxide–silicon oxide composites deposited from reactant gas mixtures of TiCl 4–SiCl 4–O 2.