The intent of this research work is to explore the relationship between the Additive Manufacturing (AM) processes, microstructure and resulting properties for titanium and alloys. Today, many high performing components are being produced by AM using titanium alloys . Titanium alloys have been used in the manufacture of turbine blades and bio-materials as they have corrosion resistance, light and good specific strength. Because of high specific strength and corrosion resistance of the titanium alloys have made them suitable for aerospace industries. There is wide scope for weight reduction in aircraft industry. This is mainly due to higher payoff for weight reduction. In this context, titanium alloys paly a very significant role in weight reduction. Titanium is introduced into market much later than steel and aluminium.
Titanium alloy, Ti-6Al-4V, is used in the manufacture of airframes, wings and landing gears.
The chapter covers on the following topics:
- Classification of Titanium alloys
- Additive Manufacturing (AM) Process
- Microstructure and properties of titanium and alloys
- Applications
- Titanium alloys -classification
- ?-type
- ?-type
At temperatures above (883 0C) titanium exists in ?-phase. At temperatures below (883 0C) pure titanium exists in ? phase. At Beta Transus Temperature, allotropic transformation of titanium from ?-phase to ? phase happen.
Adding alloying elements in titanium results in stable ?-phase / ? phase.
Commonly used alloying elements for stabilizing ?-phase include : Aluminium (Al), Nitrogen (N), Gallium (Ga), and Oxygen (O).
Commonly used alloying elements for stabilizing ? -phase include: Molybdenum (Mo), Tungsten (W), Vanadium (V), Silicon (Si) and Tantalum (Ta)
?-type titanium alloys contain atoms in Hexagonal Closest Packing crystal lattice. They contain Aluminium as the major alloying element. They have good fracture toughness. These alloys also have ?-type, which consists of Cubic Body Centred Crystal lattice.
Titanium alloys can be classified as follows:
- Commercially pure and low alloyed titanium alloys is composed of mixture of grains of ?-phase and ? phase (spheroid). They contain small amounts of iron for giving stability to ? phase. They have very low mechanical strength and good corrosion resistance. Corrosion resistance can be further improved by adding small amounts of palladium (Pd), molybdenum (Mo) and Nickel (Ni).
Strength of these alloys is greatly governed by Oxygen content. Tensile strength of these alloys can be improved by increasing Oxygen concentration from 0.18% to 0.4%. These alloys are used in the manufacturing of equipment for chemical processing, marine components, aircraft components, gas compressors and desalination equipment.
Additive manufacturing is capable of producing high strength components, which are comparable to that produced from conventional methods. Both static strength and fatigue strength of AM fabricated components depends upon their microstructure.
? alloys:
Commercially pure (cp) titanium alloys differ in mainly in oxygen contents.
Grade 1-4 cp titanium alloys have tensile strength from 240 to 740 MPa (at room temperature). Grade -1 has excellent cold formability. It is widely used in deep drawing operations. In general, these alloys may be used wherever excellent corrosion resistance is required as well as low tensile strength. Grade-2 alloys have tensile strength from 390 to 540 MPa. Grade-3 has relatively higher strength and is used in the construction of pressure vessels. Grade-4 has highest strength (up to 740 MPa). This alloy is the preferred choice for fittings as well as mountings. Ti-5Al-2.5Sn has high strength. It is mainly used in the construction of hydrogen tanks and pressure vessels. The alloy has excellent weldability properties.
To summarize, in the current research work, an attempt has been made to explore the relationship between the Additive Manufacturing (AM) processes, microstructure and resulting properties for titanium and alloys. The findings of the current research would be useful both for academicians and practitioners.
Keywords
Artificial Intelligence, Industry 4.0, Additive manufacturing, AM, Smart manufacturing
Acknowledgments
The author would like to express his sincere thanks to the management of Pandit Deendayal Petroleum University, for providing the necessary infrastructure and timely support.
Biography
Dr. M.B.Kiran is an Associate Professor in the Department of Mechanical Engineering, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar, Gujarat, INDIA. He earned his graduation (B.E.) from the University of Mysore in 1987. He did his post-graduation (M.E.) in Production Engineering from P.S.G. College of Technology (1991) and Doctoral degree (Ph.D.), in Surface Metrology from Indian Institute of Technology (I.I.T.), Madras in 1997. He has Industry/Research/Teaching experience of 25 years. He has published technical papers in many reputed national/international journals and conferences. He is a member of the Project management Institute (P.M.I.), U.S.A. He is a certified project manager (P.M.P.) from P.M.I. He has completed many mission-critical projects. He has conducted many training programs for working executives.