Mechanical Properties of Ti6Al4V Fabricated by Laser Powder Bed Fusion: A Review Focused on the Processing and Microstructural Parameters Influence on the Final Properties

Abstract

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).

Microstructure Tailoring for High Strength Ti-6Al-4V without Alloying Elements through Optimized Preheating and Post-Heating Laser Scanning in Laser Powder Bed Fusion

“…This is achieved by utilizing the laser source with multi-laser scan strategies before and after the melting scan. The average reported YS of the literature for LPBF-fabricated Ti-6Al-4V was 1048.9 ± 120 MPa [28].…”

“…There are studies seeking solutions to address these issues through optimization of the process parameters [15,26,27]. In addition to these, there are a great number of reported studies investigating the impact of post-HT [28][29][30][31][32][33]. Due to the requirement for advanced equipment, HT increases the production cost as well as the lead time.…”

Effects of build direction and microstructure on fatigue crack growth behavior of Ti6Al4V fabricated by laser powder bed fusion

“…[1][2][3][4] Particularly, Ti6Al4V titanium alloy is widely used to manufacture complex aerospace structural components due to its combination of excellent properties such as low density, high strength, good corrosion resistance, and heat resistance. 5,6 However, due to the poor machinability of Ti6Al4V, the cost of conventional machining is high. Consequently, the additive manufacturing of Ti6Al4V alloy parts has become a focus of the aerospace industry.…”

“…It has greatly contributed to the development of the manufacturing industry and in recent years has achieved great development in the aerospace, rail transportation, automotive, biomedical, military, and other fields 1–4 . Particularly, Ti6Al4V titanium alloy is widely used to manufacture complex aerospace structural components due to its combination of excellent properties such as low density, high strength, good corrosion resistance, and heat resistance 5,6 . However, due to the poor machinability of Ti6Al4V, the cost of conventional machining is high.…”

Effect of standoff distance on printability of aluminum 5356 alloy through extrusion-based metal additive manufacturing using induction heating

“…29 To improve the mechanical performance of finished goods from selective laser melting, post-processing, like hot isostatic pressing or heat treatment, is required to address microstructural flaws. 30 High manufacturing costs are also a result of this post-processing and the slow deposition rate of powder-based metal AM. Lasers and electron beams are currently used as energy sources to melt metallic materials in powder, making metal AM very costly.…”