Today, the use of material extrusion processes, like fused deposition modeling (FDM), in aerospace, biomedical science, and other industries, is gaining popularity because of the access to production-grade thermoplastic polymer materials. This paper focuses on how modifying process parameters such as build orientation, raster angle (RA), contour width (CW), raster width (RW), and raster-to-raster air gap (RRAG) can improve ultimate tensile strength (UTS), Young's modulus, and tensile strain. This was assessed using three methods: default, Insight revision, and visual feedback. On average, parameter modification through the visual feedback method improved UTS in all orientations, 16% in XYZ, 7% in XZY, and 22% in ZXY.

To build multimaterial objects using additive manufacturing (AM), modifications to the majority of current conventional AM processes are required. Typically, deposition can only occur on flat surfaces and motion requires three degrees of freedom (DOFs) in a Cartesian coordinate system. In this work, metal wire and mesh were successfully embedded using ultrasonic energy on curved thermoplastic structures fabricated via the material extrusion AM technology named fused deposition modeling (FDM). The direct wire embedding process was executed by installing an ultrasonic horn on a three-axis prismatic machine and fixing an FDM-built curved part on a rotary stage. Since the part was nonplanar, a need existed to accurately place metal wire along the curved surface with positions defined by Cartesian and angular coordinates. Two additional DOFs were generated by moving both the build platform and tool head, and trajectory planning allowed for synchronized motion between the two motion systems.

This research presents a simple method to additively manufacture Cone 5 porcelain clay ceramics by using the direct ink-write (DIW) printing technique. DIW has allowed the application of extruding highly viscous ceramic materials with relatively high-quality and good mechanical properties, which additionally allows a freedom of design and the capability of manufacturing complex geometrical shapes. Clay particles were mixed with deionized (DI) water at different ratios, where the most suitable composition for 3D printing was observed at a 1:5 w/c ratio (16.2 wt.%. of DI water). Differential geometrical designs were printed to demonstrate the printing capabilities of the paste. In addition, a clay structure was fabricated with an embedded wireless temperature and relative humidity (RH) sensor during the 3D printing process. The embedded sensor read up to 65% RH and temperatures of up to 85 °F from a maximum distance of 141.7 m. The structural integrity of the selected 3D printed geometries was confirmed through the compressive strength of fired and non-fired clay samples, with strengths of 70 MPa and 90 MPa, respectively. This research demonstrates the feasibility of using the DIW printing of porcelain clay with embedded sensors, with fully functional temperature- and humidity-sensing capabilities.

Build defects, such as nozzle clogging and thermal substrate deformation, are common in material extrusion additive manufacturing technologies, and are difficult to detect because of the high-temperature environment of fused deposition modeling (FDM) machines that do not accommodate internal sensors. To overcome this difficulty, this paper integrated an external sensor to monitor the supply current of the motor that fed filament into an extrusion head. This paper describes the investigation of the relationship between the deposition status and the reaction torque on the filament-feed motor. A dynamic model of the internal operation of the FDM extrusion head was developed and used to infer printing defects. The change in reaction force opposing extrusion was indirectly measured by monitoring the current delivered to the filament-feed motor, and consequently, the use of other sensors in the high-temperature chamber was avoided. An analysis of the supply current, in both time and frequency domains, enabled the detection of defects during material deposition.