Preparing 3D Functional Gradients for SLS
The creation of three dimensional functional graded materials by powder processing methods requires the capability to arrange a sequence of two dimensional images that can be presented to a solid freeforming device. Planar stacking methods can only achieve a one dimensional gradient. We describe the acoustic control of powder metering and dispensing valves in which the flow rate and switching of powders from a capillary can be controlled using the frequency and amplitude of acoustic vibration from a computer sound card. An orchestra of such valves can be used to pattern layers of powder on the building platform which forms part of a 3-axis table in the Selective Laser Sintering (SLS) process. Patterns and gradients were prepared using copper and steel powders.
Omer Van der Biest, Michael Gasik, Jozef Vleugels
S. F. Yang and J. R.G. Evans, "Preparing 3D Functional Gradients for SLS", Materials Science Forum, Vols. 492-493, pp. 749-754, 2005