Mechanical Properties and Microstructural Features of Direct Laser-Deposited Ti-6Al-4V

Direct laser deposition (DLD) is a means to additively manufacture metallic, functional parts via blown powder (or wire) and in situ laser delivery. Despite the various research efforts in characterization of post-manufactured DLD parts and in optimizing the DLD process, there are still areas that need to be further explored to promote the widespread adaption and utilization of DLD parts for engineering application. This article aims to review the mechanical properties of Ti-6Al-4V parts manufactured via DLD, including tensile and fatigue characteristics and microstructural features. These mechanical properties will be related with DLD process parameters (e.g., laser power, traverse speed, etc.) and resultant phenomena such as melt pool dynamics and part thermal history. Because fatigue is a main failure mode of parts in many engineering applications, the fatigue behavior of Ti-6Al-4V parts fabricated via DLD is highlighted and discussed in detail.