Modeling the filament of magnesium alloys

The realization of the required geometry when representing the complex part of an object is determined by discretization of the material amount to be applied by a filament. The FDM of metals could in this way be competitive with conventional technologies to net shape making. The possibility to realize smaller and smaller filaments whose characteristics can be given in the extruding tool-material system by using proper geometries and parameters in order to produce the temperature rise inside the container is investigated. The analytical modeling proposed describes the extrusion behaviour of two magnesium alloys, that are the AZ31 and the ZM21 ones. That to perform a filament section of 0.4-0.5 mm in radius, beginning by a one of about 1.5 mm, with which to apply metal ribs. The effect of friction, distortion and heating phenomena as well as the solid fraction are considered on the stress vs. displacement curves inside the extruder until submillimeter diameter. The material model updated to consider the higher strain rates evidences the different behaviour of the models in describing different strain rates conditions useful to realize the filament geometry.