Mechanical properties of Ti6Al4V fabricated by laser powder bed fusion: a review focused on the processing and microstructural parameters influence on the final properties

Ti6Al4V alloy is an ideal lightweight structural metal for a huge variety of engineering applications due to its distinguishing combination of high specific mechanical properties, excellent corrosion resistance and biocompatibility. In this review, the mechanical properties of selective laser-melted Ti6Al4V parts are addressed in detail, as well as the main processing and microstructural parameters that influence the final properties. Fundamental knowledge is provided by linking the microstructural features and the final mechanical properties of Ti6Al4V parts, including tensile strength, tensile strain, fatigue resistance, hardness and wear performance. A comparison between Laser Powder Bed Fusion and conventional processing routes is also addressed. The presence of defects in as-built Ti6Al4V parts and their influences on the mechanical performance are also critically discussed. The results available in the literature show that typical Laser Powder Bed–Fused Ti6Al4V tensile properties (>900 MPa yield strength and >1000 MPa tensile strength) are adequate when considering the minimum values of the standards for implants and for aerospace applications (e.g., ASTM F136–13; ASTM F1108–14; AMS4930; AMS6932).This work was supported by FCT national funds, under national support to an R&D units grant, through the reference projects UIDB/04436/2020 and UIDP/04436/2020 and also through the projects ADD2MECBIO (PTDC/EME-EME/1442/2020) and Additive_Manufacturing to Portuguese Industry_POCI-01-0247-FEDER-024533