The mechanical behaviour of interpenetrating phase composites - II: a casestudy of a three-dimensionally printed material

The three-dimensional printing process allows the manufacture of components of complex shape. In the process, a binder is selectively sprayed onto lay ers of powder in a bed in sequence. Any unbound powder is removed from the component and the remaining powder is sintered to form the part. In produci ng parts for tooling, the porosity of the sintered powder is relatively hig h and is subsequently infiltrated with a second material, giving an interpe netrating phase composite in which each phase forms a completely interconne cted network. In this paper, we describe an experimental and modelling inve stigation of the mechanical and thermal expansion properties of stainless-s teel/bronze composites produced by three-dimensional printing. The properti es are well-represented by non-linear finite element analysis based on a un it cell model with periodic boundary conditions. Numerical results show tha t the presence of thermal residual stresses and porosity contribute to a re duction in effective elastic moduli for these composites, These factors do not significantly affect flow or thermal expansion proper-ties. (C) 2000 El sevier Science Ltd. All rights reserved.