Trajectory Strategy Effects on the Material Characteristics in the WAAM Technique

Abstract

The wire Arc Additive Manufacturing (WAAM) technique has evolved into a cutting-edge 3D printing technique. This study surveys the influences of trajectory on the characteristics of low-carbon steel samples generated by the WAAM technique. The results show that the grains in the WAAM samples are isotropic, with grain size numbers ranging from 7 to 12. Strategy 3, with a spiral trajectory, has the smallest grain size, while strategy 2, with a lean zigzag trajectory, has the largest. The variations in grain size are caused by differences in heat input and output during the printing process. The WAAM samples achieve a significantly higher UTS value than the original wire, demonstrating the WAAM technique’s benefit. Strategy 3, with a spiral trajectory, achieves the highest UTS value, 616.5 MPa, 24% higher than the original wire. The UTS values of strategy 1 (horizontal zigzag trajectory) and strategy 4 (curve zigzag trajectory) are comparable. WAAM samples have significantly higher elongation values than the original wire, with only 22% elongation. The sample with the highest elongation value, 47.2%, was produced by strategy 3. Strategy 2 has an elongation value of 37.9%. The value of elongation is proportional to the value of UTS. WAAM samples have average elastic modulus values of 95.8 GPa, 173.3 GPa, 92.2 GPa, and 83.9 GPa, corresponding to strategies 1, 2, 3, and 4. Only a strategy 2 sample has a similar elastic modulus value to the original wire. All samples have dimples on the fracture surface, indicating that the WAAM samples are ductile. These fracture surfaces’ equiaxial shape corresponds to the original microstructure’s equiaxial shape. The results provide the optimal trajectory for the WAAM products is the spiral trajectory, while the lean zigzag trajectory gains only modest characteristics.

Movement Strategy Influences on the Characteristics of Low-Carbon Steel Generated by the Lamination Object Manufacturing Method

“…Therefore, after melting, the grain has less time to grow during the crystallization process, leading to a smaller grain size. This phenomenon is similar to that which Uyen et al [35] report. In reverse, the other movement strategy has a denser pathway, leading to a higher heat concentration.…”

Symmetry Analysis in Wire Arc Direct Energy Deposition for Overlapping and Oscillatory Strategies in Mild Steel

“…These parameters must be carefully controlled and adjusted to obtain the best mechanical properties and dimensional and structural accuracy of the part. In recent times, research on this technology has focused on the control and monitoring of these parameters [8][9][10] and the study of different material deposition techniques and their influence on them [11][12][13][14][15].…”

“…By moving the torch back and forth, heat is distributed more evenly, reducing the possibility of deformation or cracking in the part. In addition, this strategy can help reduce porosity formation and stress buildup in the part, which can improve part strength and durability [11].…”