Modelling for randomly oriented multi material additive manufacturing component and its fabrication

•Demonstrates modelling and fabrication of randomly oriented multi material (ROMM).•Polyjet 3DPrinting (3DP) is used for ROMM fabrication with reinforcement & matrix.•Polyjet 3DP place reinforcement (plastic) uniformly & randomly in matrix (elastomer).•Reinforcement in ROMM shows nearly 20% higher stiffness compared to pure matrix.•ROMM of various orientations shows similar stress–strain & fracture behaviour.

Additive Manufacturing (AM) is one of the advanced manufacturing processes, which was initially used only for visualization purpose as Rapid Prototype (RP) components. In later stages due to the advancement of materials processing in AM technology it is also used to manufacture tools and functional parts. In material science field AM is very much useful in the development of multi material component such as functionally gradient materials, heterogeneous material structures and porous material structures. These structures have tremendous applications in the field of aeronautical, automobile and medical industries. But some of the traditional techniques, which are used for fabrication of these structures, have difficulties such as uniform & random distribution, size and shape control and maximum percentage of secondary materials to the primary materials. In this work a novel methodology is introduced for the fabrication of randomly oriented multi material (ROMM) using Polyjet 3D Printing (3DP) machine, which takes into account for the distribution of plastic reinforcement in matrix elastomer as modelled using Computer Aided Design (CAD) software. CATIA VB SCRIPT has been used for ROMM CAD modelling. Stress–strain behaviour of Polyjet 3DP component (with pure elastomer and with randomly oriented plastic reinforced elastomer) is carried out in Universal Testing Machine (UTM). It has been found that ROMM with plastic reinforcement provides significantly improved stiffness compared to pure elastomer component. In addition, the stiffness is consistent among different ROMM Polyjet 3DP components, which were taken at three different orientations (Horizontal, Inclined and Vertical) from the ROMM rectangular plate domain. It shows that reinforcement is uniformly distributed. Normal distribution curve and volumetric analysis is carried out in ROMM to verify uniform and random distribution of plastic reinforcement in elastomer. Based on the experimental results, this modelling and manufacturing technique can be used for the spatial orientation of reinforcement in the ROMM component and its fabrication with better stiffness for form & fit and functional parts applications.