Photoforming of Metal Components with Designed Porosity

This proposal outlines plans for utilizing visible light stereolithography-based techniques for the fabrication of near net shape foam metal components with designed and controlled porosity. Design and control of three basic aspects of pore structures in foams allow significant improvement in their performance: 1) pore sizes, shapes and orientations; 2) pore spatial distribution in terms of amounts of pores in one or more types; and 3) pore spatial distribution in terms of spatial graduation in content and/or character in the body (functionally graded foams). The intrinsic advantages of SFF techniques in forming designed pore structure with the above cited character are 1) the ability to additively place material on a scale which is desirable for foam structure formation and 2) to do this integrally with the fabrication of a near net shape object. Two approaches to photoforming of pore structure are proposed, one that utilizes a pore producing ink that is "printed" in desired locations and the other in which pores are directly imaged in the desired shape, size, orientation and distribution. Capability to produce pores ranging in size from 1¿m up to several millimeters with pore volume fraction ranging from 20% up to 70% are expected.