# Titanium Additive Manufacturing with Powder Bed Fusion: A Bibliometric Perspective
## 1 Introduction
This is due to its typically lower resolution and higher costs associated with the equipment and materials. For the sake of clarity, Figure 1 illustrates the principal processes used in titanium additive manufacturing, as mentioned above. Figure 1: Schematic of the principal processes used in titanium additive manufacturing. The evolution of research interest in titanium AM is closely aligned with advancements in high-performance industries, particularly aerospace and biomedical sectors. As demand for lightweight, high-strength materials grows, AM has emerged as a viable solution for complex, customized titanium components, indicating that industry needs to significantly drive research activity and innovation. Within this landscape, PBF and DED have established themselves as dominant approaches, each with distinct advantages and adoption patterns. PBF is preferred for high-resolution components in aerospace and medical applications where precision is paramount, while DED excels in producing larger parts and facilitating repairs, finding applications in heavy machinery and aerospace component maintenance. This differentiation highlights the complementary nature of these methods, with each fulfilling specific needs in the titanium industry and contributing to the overall advancement of AM technologies. Titanium alloys are extensively utilized in both research and industry because of their exceptional properties. The most common titanium alloys include Ti-6 Al-4V, Ti-6 Al-2 Sn-4 Zr-2 Mo, and Ti-5 Al-2.5 Sn. Ti-6 Al-4V, also known as Grade 5, is the most prevalent alloy, offering an excellent balance of strength, corrosion resistance, and weldability [31; 32; 33; 34]. It is extensively used in aerospace for components such as turbine blades, in the biomedical field for implants and prosthetics, and in automotive and marine industries for high-performance parts. Ti-6 Al-2 Sn-4 Zr-2 Mo is used in high-temperature applications, particularly in jet engines and airframe structures, due to its superior creep resistance [31; 32]. Ti-5 Al-2.5 Sn, known for its good weldability and moderate strength, is often used in airframe and cryogenic applications [35; 36]. These alloys continue to be a focus of intensive research to further enhance their properties and expand their applications in various high-performance industries. Computational simulations have become invaluable tools for understanding and predicting complex thermal histories, phase transformations, and resulting microstructures in PBF-manufactured titanium materials. These simulations enable researchers and engineers to optimize process parameters, predict material properties, and improve the quality and performance of components. By integrating multi-scale modeling approaches, from thermal-fluid simulations of melt pool dynamics to microstructure evolution predictions, computational frameworks can provide comprehensive insights into the PBF process for titanium alloys, facilitating the development of tailored microstructures and properties for specific applications [37; 38]. Despite significant advancements in titanium additive manufacturing, technical and scientific challenges persist that require a deeper understanding, including aspects such as the quality and consistency of the produced material, mechanical and microstructural properties, and process parameter optimization. In this context, a bibliometric review can provide a comprehensive overview of the current state of research, identifying trends, gaps and future opportunities in this field. Specifically, this review seeks to answer the following research questions: What are the primary thematic trends and key research areas in titanium AM by PBF? How has the geographic distribution of research impacted the development of titanium AM by PBF? Which process parameters and materials dominate the field, and what gaps remain for future exploration? In this regard, the primary objective of this article is to conduct a bibliometric review of research related to titanium AM using PBF technology.