This paper deals with the modeling and process planning of solid freeform fabrication
(SFF) of 3D functionally graded materials (FGMs). A novel approach of representation and
process planning of FGMs, termed as equal distance offset (EDO), is developed. In EDO, a
neutral arbitrary 3D CAD model is adaptively sliced into a series of 2D layers. Within each
layer, 2D material gradients are designed and represented via dividing the 2D shape into
several sub-regions enclosed by iso-composition contours. If needed, the material
composition gradient within each of sub-regions can be further determined by applying the
equal distance offset algorithm to each sub-region. Using this approach, an arbitrary-shaped
3D FGM object with linear or non-linear composition gradients can be represented and
fabricated via suitable SFF machines.Mechanical Engineerin
