In the current study, the additive manufacturing of nylon by fused deposition modeling is conducted based on statistical analysis. Besides, the aim of this study is the influence of process parameters, namely layer thickness (0.15 mm-0.35 mm), infill percentage (15-55%), and the number of contours (2-6) on the maximum failure load, parts weight, elongation at break, and build time. The experiment approach was used to optimize process parameters based on the statistical evaluates to reach the best objective function. The minimum value of build time and maximize of the failure load were considered as objective functions. The response surface method is regarded as an optimization process parameter, and optimum conditions were studied by experimental research to evaluate efficiency. Based on the results, the layer thickness is the significant primary variable for all responses. The experimental evaluation showed that the maximum values of failure load and elongation were obtained by changing the layer thickness from the lowest to the highest. By reduction in layer thickness at the same printing speed, the cooling rate increases, which results in greater strength and less elongation. As a result, it could be concluded that by increasing the number of contour layers from 2 to 6, the maximum failure force increased 42%. Increasing the contours due to the similar effect to increasing the infill density, increases the failure force and production time, which is also confirmed by the ANOVA.

This study aims to systematically experimental investigate the influence of infill-patterns (IPs) on specific mechanical responses of parts fabricated by fused deposition modeling (FDM). A poly-lactic-acid (PLA) feedstock filament is utilized in the manufacturing process. Furthermore, six types of infill-patterns (deposition angle), namely full honeycomb, rectilinear, triangular, fast honeycomb, grid, and wiggle, are designed and printed. In order to determine the mechanical properties of manufactured parts, tensile tests are carried out. The mechanical properties such as extension, stress, elongation, energy, and Young’s modulus are considered as objective functions. As a result, there is a direct correlation between mechanical properties and infill patterns. Thus, it is essential to select the best infill-pattern in terms of their applications, giving sufficient strength without overdoing time and cost. Based on the results, a triangular infill-pattern has a maximum value of ultimate tensile strength and E-module (15.4 and 534 MPa, respectively). On the other hand, the wiggle pattern is more flexible.

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4D printing is a pioneer field to produce functional smart devices. The combination of 3D printing and smart material is called as 4D printing. The extra dimension refers to time in order to shape transformation of the printed part during time. FDM is a universal process to 3D printing of thermoplastic polymers. Therefore, for successful and typical 4D printing a deep understanding of every aspect of shape memory polymers especially thermoplastic polymers is necessary. So, in this chapter, shape memory polymers, printing preparation such as filament production and FDM printing parameters, finally applications, previous finding and functional printed parts by FDM have been studied detailed.

This paper aims at analyzing the deformation behavior of tailor welded blanks (TWBs), manufactured by laser beam welding (LBW) and gas tungsten arc welding (GTAW), through the deep drawing process. Dissimilar and similar steels with different thicknesses were used in the production of tailor welded blanks. The Nd: YAG laser welding method with nitrogen (N2) as the shielding gas was used to join TWBs. The effects of some significant process factors, namely welding speed, blank holder forces (BHF), material properties of base metals, dry/lubricated condition and laser spot size was experimentally investigated on the weld line movement and drawing depth. Results indicated that using LBW with optimum parameters for the production of dissimilar TWBs caused the control of failure in the weaker base metal. Results showed that the sound welds were produced in similar TWBs with a thickness ratio of 2 when using GTAW, but the weld quality was poor when using LBW. Moreover, it is observed that the critical stresses were taken place outside of the weld zone and rupture due to the high heat input of laser and metallurgical changes of the base metal that occur in the pre-softening zone. In addition, the weld line movement occurred as a result of plastic strain change of the weld joint that caused failure-prone zone creation as well as the adverse wrinkling.

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