The Basic Research Of The Path-planning Of Functionally Graded Material Part Fabricated By Plasma Deposition Manufacturing

PDM(Plasma Deposition Manufacturing) is a new technology, which is based on Rapid Prototyping and can directly and rapidly fabricate functional metal parts having high intensity and full density by plasma high energy density beam. PDM has some advantages: high forming efficiency, low cost, good machining flexibility, diversiform kinds of material powder, unlimited shape and size and so on.The particular characteristic of Rapid Prototyping is shaping geometry and material distribution simultaneously and adding material, which makes it become the promising way to fabricate functionally graded material(FGM) objects. The method of Plasma Deposition Manufacturing FGM parts, which combines technologies of Rapid Prototyping, CAD/CAM, Numerical Control and FGM fabrication is studied in this paper. It can not only get good quality while forming, but also be able to directly manufacture metal parts having arbitrarily complicated inner structure and special function. Because of unification of material design and part fabrication, it not only realize different material composition and complicated structure in the same layer, but also realize arbitrary varieties of material composition and structure form between different layers, all of which makes it possible to directly manufacture high performances parts.Based on the STL model, the basic theory of direct metal deposition based on revolving surface is studied. In order to achieve direct metal deposition on revolving surface, a numerical control rotary axis is added to the Plasma Deposition equipment, and a STL model slicing algorithm as well as path-planning algorithm based on cylinder surface slicing is proposed. Based on the proposed slicing algorithm, data processing and NC code generating software are developed, and several machining experiments are carried out.The modeling, data representation and processing, fabrication technics of Functionally Graded Material part are studied in this paper. A novel approach of representation and process planning for solid freeform fabrication of FGM objects, termed as iso-composition contour Line/Face, is proposed based on STL solid model, which can accurately describe geometry and material distribution information and represent gradient distribution of complicated part. In this model, the material information is associated with a series of 2D layers which an arbitrary 3D CAD model is adaptively sliced into. Whereafter, within each layer, continuous distribution of material information is discretized into iso-composition contour lines or faces, which can be used for subsequent path-planning. Finally, a functionally graded part is presented to demonstrate the representation and path-planning facing to Direct Plasma Deposition.