Additive manufacturing (AM) technology has gained significant popularity, among which Fused Deposition Modeling (FDM) has emerged as the predominant technique for 3D printing. FDM offers the unique ability to achieve the desired and tailored engineering properties required for specific applications. This experimental study investigates the influence of varying FDM process parameters on the mechanical properties and highlights the optimal set of parameters for better tensile strength for a bi-layered composite of PLA-ABS (polylactic acid and acrylonitrile butadiene styrene). Also, it investigates the most-to-least influential printing parameters. Four process parameters were played out i.e., Infill density (50%, 75%, and 100%), number of layers (20,25 and 30), printing speed (20 mm sec⁻¹, 40 mm sec⁻¹, and 60 mm sec⁻¹), and bed temperature (90 °C, 95 °C, and 100 °C), while keeping other parameters constant. Taguchi optimization technique was used for optimization and experiments were designed according to Taguchi orthogonal array L9 (3 4). After printing, the samples were evaluated for tensile properties and the results were analyzed. It is found that the infill density is the most influential parameter while bed temperature is the least influential. Infill density of 75%, 30 layers per part, a printing speed of 20 mm sec⁻¹, and a bed temperature of 100 °C are the optimal set of parameters for better tensile strength. Alongside, percent elongation, printing time, and strength-to-weight ratio were also analyzed and correlated.

This study investigates the impact toughness of 3D-printed PLA structures with Hilbert curve and honeycomb infill patterns at various raster angles. Samples were fabricated using Fused Deposition Modeling (FDM) and tested for impact energy absorption using the Charpy test. The results showed that specimens printed at a 90° raster angle exhibited the highest impact absorption. Hilbert curve patterns demonstrated 20.6% less energy absorption than plain samples with 40% infill and 11% higher energy absorption than plain samples with 100% infill, highlighting the significant role of material utilization in enhancing structural integrity.

Laminated composites are a key area of research due to their cost-effectiveness and productivity. Fiber-reinforced laminated composite structures are widely used for their excellent strength-to-weight ratio. These composites are typically manufactured using the Vacuum Assisted Resin Transfer Molding (VARTM) method. In laminated composites, properties are highly dependent on the orientation of the laminates and their proper adhesion with the epoxy matrix. This study focuses on the application of VARTM in fabricating fiberglass laminated composites using three glass fiber laminates oriented at 0°, 45°, and 90°, impregnated with epoxy resin under vacuum assistance. The features of these composites are compared with those of composite with laminates parallel to one other at 0° and 45°. The manufacturing process involved curing the composite sheets for 24 h, followed by cutting tensile specimens according to standard D3039. Results showed that specimens with all laminates oriented at 0° to the loading direction exhibited the highest strength of 253 MPa, while specimens with laminates oriented at 45° showed the lowest strength 69 MPa and highest elongation, i.e., strain of 0.22 mm/mm.

3D printing is a rapidly advancing field, particularly with the emergence of industrial applications. Within this realm, multi-material printing is gaining prominence, finding applications across various industries. A significant challenge in multi-material 3D printing is the potential for delamination between layers or poor adhesion. Our study addresses this challenge by focusing on joining methodologies. Specifically, we apply mechanical interlocks with varying orientations (0 °, 45°, and 90 °) to achieve the enhanced impact strength. with PLA Pro material. The toughness and fracture properties of interlocked samples were compared with standard printed pure samples. Our findings indicate that the interlocked samples exhibit superior strength and distinctive fracture behaviors that can be used to print to multi-materials in 3D printing. Furthermore, the best performing interlock was further optimized based upon raster angle. The result shows best performance at 45° raster angle. This work can lead to multi-material printing in various industries like health care, manufacturing, and process industry.