Laser induced paste agglomeration : a new process for rapid prototyping

A new process called « Laser Induced Paste Agglomeration» (LIPA) is being developed for the direct manufacture of tooling and functional prototypes from the data computed by a CAD software. The paste is composed of a powdered material and a liquid binder. The process consists in depositing a thin layer of paste then in solidifying a part of it by a laser beam. The 3D object is then manufactured layer by layer. Many materials, such as polymers, metals and ceramics, can be used to manufacture parts by this process. This paper mainly describes the agglomeration of ceramic paste, which is composed of alumina powder and a silicate binder. The parts made of ceramic manufactured by this technique are porous. After sintering at 800°C, the strength of four-point bending tests on the samples (10.6-17.3 MPa) is comparable with some other similar processes (10-18.7MPa). The phase transformations during the agglomeration and the sintering are also dissussed