A comprehensive study on the fabrication and characterization of Ti–48Al–2Cr–2Nb preforms manufactured using electron beam melting

Cakmak, Ercan; Nandwana, Peeyush; Shin, Dongwon; Yamamoto, Yukinori; Gussev, Maxim N.; Sen, Indrani; Seren, M. Hazar; Watkins, Thomas R.; Haynes, J. Allen

doi:10.1016/j.mtla.2019.100284

Cited by 36 publications

(16 citation statements)

References 36 publications

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“…At room temperature, TiAl intermetallic alloys comprise of three major phases of intermetallics, namely; α 2 -Ti 3 Al (D0 19 structure), γ-TiAl (L1 0 structure) and β o -TiAl (B2 structure) [ 1 , 4 , 7 , 18 , 20 , 26 , 27 , 28 , 29 ]. The γ-TiAl phase has L1 0 tetragonal structure while α 2 -Ti 3 Al phase has a D0 19 hexagonal structure [ 30 , 31 , 32 , 33 , 34 ]. Also, the γ-TiAl phase is formed at 49 to 66 at.% Al content [ 14 ] that could be stabilized up to its melting temperature (~1450 °C) [ 28 ].…”

Section: Introductionmentioning

confidence: 99%

“…According to Singh et al [ 31 ], TiAl intermetallic alloys lack hot-workability due to reasons such as (i) low dislocation mobility, (ii) shortage of independent slip system resulting in the materials’ plastic anisotropy, and (ii) lack of mobility at grain boundaries and diffusivity caused by retarded recrystallization and recovery. Also, the practical application of TiAl alloys is inhibited by poor oxidation at elevated temperatures [ 42 ].…”

Section: Introductionmentioning

confidence: 99%

“…Titanium aluminides are problematic to process due to their brittle nature, hence, limiting its widespread production. The intrinsic brittleness at RT and poor hot-deformability limit its application in manufacturing complex-shaped structural components [ 14 , 31 , 39 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. Consequently, conventional processing of TiAl-based alloys such as forging and extrusion are restricted; while casting is known to always produce coarse microstructure and arbitrary defects resulting in inhomogeneous mechanical properties [ 20 , 47 ].…”

Section: Introductionmentioning

confidence: 99%

“…It is reported that the nearly fully lamellar and/or fully lamellar microstructures could provide the much-needed combination of mechanical properties using a viable production method and provide structural integrity during the components’ lifetime [ 5 , 7 , 14 , 16 , 22 , 30 , 46 , 51 , 52 ]. The duplex or equiaxed microstructure (γ+α 2 ) provides adequate ductility and fatigue but it exhibits low creep resistant and fracture toughness; while the microstructure with fully lamellar (with alternating plates of γ and α 2 phases) demonstrates superior fracture toughness and creep resistant but demonstrates poor ductility [ 30 , 31 , 52 ]. Hence, the choice of final microstructure during processing is very essential to obtain the best combination of mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

“…A semi-coherent interface would result from any slight difference in the lattice parameters of both γ and α 2 phases. The transfer of dislocations from one phase to the other is difficult because α 2 -phase is a very brittle phase; thus, reducing the overall ductility in fully lamellar microstructures [ 31 ].…”

Section: Introductionmentioning

confidence: 99%

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Characteristic effects of alloying elements on β solidifying titanium aluminides: A review

Raji

Popoola

Pityana

2020

Heliyon

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The high strength-to-weight ratio property of titanium aluminide (TiAl) based intermetallic alloys makes researchers regard this type of material as a potential replacement for the heavier superalloys of nickel. These alloys have been applied as turbocharger wheels of automobile and turbine blades of aircraft engines. A much recent alloy type of TiAl called the TNM alloy has emerged and primarily amenable to mechanical working; while providing the best combinations of mechanical properties that could be achieved through manufacturing processes with subsequent heat treatments. This is attained by solidifying entirely through the disordered β-phase (A2 structure). Effects of major alloying elements such as strength improvement, microstructural stability and phase formation demand the understanding of these alloying elements addition in TiAl-based intermetallic alloys. This review paper aims at encapsulating several works regarding the effects of major alloying elements on β-solidifying TiAl-based alloys and summarizing the characteristic effects of Si for these types of alloys. An impetus for future works on these types of intermetallic TiAl-based alloys is also presented.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Characteristic effects of alloying elements on β solidifying titanium aluminides: A review

Raji

Popoola

Pityana

2020

Heliyon

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On the Formation Mechanism of Banded Microstructures in Electron Beam Melted Ti–48Al–2Cr–2Nb and the Design of Heat Treatments as Remedial Action

et al. 2021

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The formation mechanism of banded microstructures of an electron beam melted engineering intermetallic Ti–48Al–2Cr–2Nb alloy, the solidification behavior, and the heat treatment response are investigated via a process parameter study. Scanning electron microscopy, hardness testing, X‐ray diffraction, electron probe microanalysis, thermomechanical analysis, electron backscatter diffraction, heat treatments, as well as thermodynamic equilibrium calculation, and numerical simulation were performed. All specimens show near‐γ microstructures with low amounts of α2 and traces of βo. Fabrication with an increased energy input leads to an increased Al loss due to evaporation, a lower α‐transus temperature, and to a higher hardness. Banded microstructures form due to abnormal grain growth toward the bottom of original melt pools, whereas α2 in Al‐depleted zones enables a Zener pinning of the γ‐grain boundaries, leading to fine‐grained areas. Via numerical simulation, it is shown that increasing the energy input leads to larger maximum temperatures and melt pool sizes, longer times in the liquid state, and more remelting events. Solidification happens via the α‐phase and increasing the energy input leads to an alignment of (111)γ in building direction. Furthermore, banded microstructures respond heterogeneously to heat treatments. Heat treatment is introduced based on homogenization via phase transformation to obtain isotropic microstructures.

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Heat‐Resistant Intermetallic Compounds and Ceramic Dispersion Alloys for Additive Manufacturing: A Review

Yakubov

Kruzic

2022

Adv Eng Mater

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Many industries such as aerospace, power generation, and ground transportation demand structural materials with high specific strength at elevated temperatures. Up until now, many types of heat‐resistant materials including Ni‐based superalloys, intermetallic compounds, and dispersion‐strengthened alloys have been developed for specific applications in these industries. Moreover, with the recent development of additive manufacturing techniques, these industries can now benefit from the rapid prototyping abilities, geometric freedom, and increased mechanical properties that can be achieved through various additive manufacturing processes. With this in mind, the progress made in additive manufacturing of heat‐resistant intermetallic compounds and ceramic dispersion alloys is herein examined. A brief introduction is provided on the target industries, applications, and the compositions of heat‐resistant alloys of current research interest. Then, recent research on heat‐resistant intermetallic compounds and ceramic dispersion alloys fabricated by additive manufacturing processes such as laser powder bed fusion, laser direct energy deposition, and electron‐beam powder bed fusion are reviewed with information provided on microstructure, processing parameters, strengthening mechanisms, and mechanical properties. Finally, an outlook is provided with future research suggestions.

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A comprehensive study on the fabrication and characterization of Ti–48Al–2Cr–2Nb preforms manufactured using electron beam melting

Cited by 36 publications

References 36 publications

Characteristic effects of alloying elements on β solidifying titanium aluminides: A review

Characteristic effects of alloying elements on β solidifying titanium aluminides: A review

On the Formation Mechanism of Banded Microstructures in Electron Beam Melted Ti–48Al–2Cr–2Nb and the Design of Heat Treatments as Remedial Action

Heat‐Resistant Intermetallic Compounds and Ceramic Dispersion Alloys for Additive Manufacturing: A Review

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