Additive manufacturing of metalic/polymer and/or ceramic/polymer parts through fused filament fabrication process

Abstract

The injection molding process used to manufacture metal and ceramic parts (MIM and CIM) has been developed and applied extensively in the last decades.There is an important growing market for parts manufactured by this process and a demand for multi-functional components composed of parts made from different materials such as a combination of magnetic and non-magnetic, conductive and insulating parts or hard and soft materials in the Same component. However, there are barriers that have not been overcome in practice in the field of injection molding of more than one material. It is also worth remembering that the use of injection molding in small production batches is uneconomical.In recent years Additive Manufacturing (MA) has been offering a revolutionary alternative for manufacturing parts with complex geometries. The MA is a process of manufacturing three-dimensional objects from a CAD (Computer Aided Design) model, which is characterized by the addition of material, usually in successive layers. Computer Numerial Control (CNC) equipment selectively deposits material following a trajectory generated from the slicing and preheating of the 3D model. One of the most widespread processes of this technology is Fused Filament Fabrication (FFF) or FDM (Fused Deposition Modeling)The proposal of this project is the continuation of the development for the manufacture of parts with metallic filaments by the FFF method as an alternative to the injection molding process for small / medium batches and the unprecedented development of bicomponent parts where selective deposition of the raw material is required. The properties of the raw material to be combined in the same part refer to: 1. - Mechanical properties: strength, elasticity, plasticity, ductility, fluency, resilience, tenacity, among others; 2. - Technological properties: fusibility, weldability, temperability, machinability, fatigue, among others; 3. - Thermal properties: resistance, dilation, among others; 4. - Electrical properties: conductivity, piezoelectricity, capacitance, among others; 5. - Electromagnetic properties: magnetic susceptibility, among others; 6. - Physical properties: density, specific weight, among others; 7. - Chemical properties: resistance to corrosion As examples we can mention: combination of materials with magnetic and non-magnetic, conductive and insulating properties or hard and soft materials in the same part. The only manufacturing process known to date that allows this type of selective deposition is the one proposed in this project and still not commercially exploited. The main objectives are the continuation of the development of composite metal / polymer filaments, obtaining parameters for the manufacturing of the parts by the FFF method for direct use and / or subsequent sintering, determination of the sintering parameters, manufacture of bicomponent parts and large format. Researchers have been working on this project for over a year, with results that show that the research has a concrete probability of becoming a commercial product. There is also a pending patent file in the INPI of the process in question made by the investigators (BR process 2017 001124 0). (AU)