Three-Dimensional Photochemical Machining With Lasers

This paper describes Battelle's ongoing research efforts to evaluate a novel, and as yet undeveloped, technology which has the potential to revolutionize the casting industry. The key to this new technology, which may be referred to as "Photochemical Machining", or PCM, is the computer-assisted fabrication of a plastic pattern directly from design specifications by the selective, three-dimensional modification of a plastic material which is exposed simultaneously to two different laser beams which are focused onto a single point within the volume of the material. The research conducted during the past year has been successful in developing a theoretical framework for relating optical and materials properties to the performance of a PCM system. While the photosensitive materials developed to date in the course of this research do not yet perform well enough for a commercial PCM system, laboratory experiments have confirmed the formation of isolated three-dimensional polymeric shapes within a volume of monomer solution by this technique. It can be shown that the fabrication of relatively small (<10 cm on a side) three-dimensional solid objects having highly precise shapes and surface finish can, in prin-ciple, be achieved in a time of only hours or days using the PCM technique given improved materials. This technology could have a major impact on the metal casting industry if indeed it can he developed successfully.