Field feature detection and morphing-based process planning for fabrication of geometries and composition control for functionally graded materials

Abstract

The inherent limitation of most solid freeform fabrication (SFF) is deposition in the form of layers. The set-up rather than the geometry and the material composition of the part becomes more important in the process planning. For a functionally graded material (FGM), the desired composition variation is of infinitesimal order; however, the finite size of the deposition head and the molten pool allows for a quantized volume addition. Such artificial imposition of the process for the desired geometric morphology and the functional gradience of materials limit the accuracy of the part. The frequent variation in the material composition is yet another issue associated with the fabrication of FGMs. The suitability of a field can be attributed to the desired material distribution of a part. Different features of the field are identified and used as the input for process planning. The mathematical morphing of the material gradience allows a smooth variation of the material composition across the geometry of the part during deposition. The paper describes a framework for FGM representation using maxel, process planning, and implementation of the fabrication of geometries, and the control of the material composition. The experimental results for the suggested approach are described.

Isotropic Material Design

“…These features allow to classify these optimal materials as Functionally Graded Materials (FGM) characterized by the variation in composition and structure over volume, resulting in corresponding changes in its properties -see e.g. [15] where an interesting technique based on the assignment of material attributes to the quantized volume was presented making the IMD designs FGM-manufacturable.…”

“…Such conditions have not been imposed in order to show the optimum design free of any additional, technological constraints: the latter can always be assumed, while the pure optimization results seem to be of certain value, like exact elasticity solutions with all their picks of stress concentrations are no less informative than elasto-plastic solutions affected by extra parameters defining the stress limit. Taking advantage of the method presented in [15], more realistic IMD designs could be constructed making them Functionally Graded manufacturable.…”

The emergence of auxetic material as a result of optimal isotropic design

“…Very interesting technique based on the assignment of material attributes to the quantized volume was presented in Ref. , for which the new term “maxel” was for the first time introduced.…”

Modeling and Visualization of Multi-material Volumes

“…Moreover, using scalar fields provides a uniform approach to modeling geometry, FGMs, multiple material blends and microstructures with given material properties directly available for optimization [CS08] and quick meshfree simulation [FST06]. From the fabrication point of view, scalar fields are suitable for per-point control of the multi-material deposition in 3D printing [DZK06], [DMO15].…”