Abstract: In rapid prototyping (RP) field, the traditional representation methods for 3-D solid model contain only geometric information, without any corresponding materials information; Therefore, it cannot be applied to built multi-material parts. For multi-material parts fabrication, a new and more efficient representation method must be proposed, that contains both geometric information and material information of multi-material solid model. To fabricate multi-material parts, a new representation algorithm based on material boundary in manufacturing processing is presented, which combines material ID index method and material region flags method to represent the geometric information and material information for multi-material parts. Some cases verify that the proposed representation method can be used to represent the multi-material parts whose components are composite material (CM) or functionally graded materials(FGM) or their combination, and it is not affected by surface complexity and material categories; Theoretically, the method can represent any multi-material part with arbitrary surface complexity and material categories.

Key words: Geometric attribution, Material attribution, Material boundary, Multi-material solid model, Rapid prototyping