# Titanium Additive Manufacturing with Powder Bed Fusion: A Bibliometric Perspective
## 4 Discussion
Figure 15 shows the correspondence analysis plot that illustrates the distribution and relationships of key terms within the literature. Dimension 1, which explains 58.6% of the variance, separates studies focusing on process parameters and mechanical properties (e.g., \"mechanical properties\", \"process parameters\", \"microstructure\") on the left from those emphasizing technological aspects and material characteristics (e.g., \"powder bed\", \"laser beam\", \"3d printers\") on the right. Dimension 2, accounting for 21% of the variance, distinguishes more general topics related to AM (\"three-dimensional printing\", \"powder\") from more specialized studies focusing on powder properties and biocompatibility (\"bio-compatibility\", \"particle size\") at the bottom. This plot highlights the thematic diversity within the field, illustrating how research spans across broad technological themes and specific material properties. Considering the most cited and recent articles on titanium additive manufacturing, particularly in PBE, as indicated in Table 10 in the Section 3, significant advancements have been made in understanding and optimizing the process. Researchers have utilized advanced in situ characterization techniques, such as high-speed X-ray imaging and diffraction, to observe critical phenomena in real time, including melt pool dynamics, powder ejection, rapid solidification, and phase transformations. [74]. On the other hand, [PERSON] and [PERSON], in their article \"Metal Additive Manufacturing: A Review of Mechanical Properties\", provide a comprehensive overview of the mechanical properties of metallic materials produced through AM. The study focuses on two primary AM techniques: (i) powder bed fusion (including EBM, SLM, and DMLS) and (ii) directed energy deposition (such as LENS and EBF3) [48]. Here, the authors analyze how the build direction can influence the final material properties and discuss  
Figure 15: Factorial analysis: plot showing relationships among key terms, categorizing studies by focus on material properties versus technological processes. the possible sources of anisotropy, such as texture, microstructural changes, and defects. This information is crucial for understanding how to optimize AM processes to achieve parts with consistent and predictable mechanical properties. The article concludes with recommendations for future research in this field, highlighting areas that require further study to enhance our understanding and application of metal additive manufacturing. Various studies have revealed crucial details about defect formation, such as porosity and spatter, and have enabled the quantification of key parameters like solidification and cooling rates [66, 67, 68]. The formation of micro-metal vapor jets has been observed to play an important role in the redistribution of material and the surface quality of the manufactured parts [75, 76]. Furthermore, researchers have characterized the evolution of phases and residual stresses during the PBF process, providing valuable insights for controlling the microstructure and the resulting mechanical properties [77, 78, 79]. [PERSON] et al. provide a comprehensive review of metal AM in the aerospace industry [49]. This technology has transformed the sector by offering new design freedoms, lightweight structures, and improved component performance. The review focuses on key aspects of metal AM, analyzing the most used processes, such as PBF (including SLM and EBM) and DED. It also examines the metallic materials frequently employed in aerospace applications, including titanium, aluminum, nickel, and stainless-steel alloys. The article highlights significant applications of titanium, including components for propulsion systems, aircraft structures, and the repair and maintenance of aircraft parts. Research has also focused on the development of new materials and structures for biomedical applications. Titanium, magnesium, and iron alloys have been explored for the fabrication of bone implants with optimized properties [80].