TGO formation and oxygen diffusion in Al-rich gamma-TiAl PVD-coatings on TNM alloys

Kagerer, S.; Hudak, O.E.; Schloffer, Martin; Riedl, H.; Mayrhofer, Paul H.

doi:10.1016/j.scriptamat.2021.114455

Cited by 10 publications

(6 citation statements)

References 29 publications

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“…Notably, the microstructure refinement of Al 3 NiTi 2 increases with brazing temperature, TiB whiskers with unique clawlike and self-joining structures can be observed (as shown in Figure 7a 1 -d 1 ) and they are obviously coarsened at temperatures above 1200 °C. Similar phenomena were also found in previous research reported by Huang et al [35] and they pointed out that the TiB whiskers were coarsened by the remarkable increasing diffusion of B element along [1,100] directions above 1200 °C. Moreover, the length of TiB whiskers and their corresponding pinning effects sharply increase with brazing temperature, which is beneficial to further refine the microstructure of the matrix (including Al 3 NiTi 2 and Ti 3 Al) and form a strong bonding interface with the selected area matrix.…”

Section: Typical Interfacial Microstructure Of γ-Tial-brazed Jointssupporting

confidence: 90%

“…γ-TiAl alloys, which possess high specific strength, low density, good corrosion resistance, and oxidation resistance as well as excellent high-temperature performance, have been regarded as one of the most potential structural materials, especially for replacing Ni-based superalloys and heatresistant steels in aircraft turbine blade. [1,2] However, the low ductility and poor workability of γ-TiAl alloys inevitably limit their practical applications in large-size structures. [3] Therefore, numerous connection methods, such as fusion welding, [4] diffusion bonding, [5,6] and brazing, [7,8] commonly used to join γ-TiAl alloys have been proposed.…”

Section: Introductionmentioning

confidence: 99%

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Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler

Li,

Yuan,

Luo

et al. 2023

Adv Eng Mater

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Vacuum brazing of Ti–47Al–2Nb–2Cr–0.15B (at%) alloy with TiH2–Ni–TiB2 powder filler in situ assisted 20 vol% TiB whiskers is performed at 1190–1250 °C for 10 min. The microstructure evolution of the joint at various brazing temperatures and the relationship between microstructure and joint properties are systematically investigated. In the results, it is indicated that the interfacial microstructure of the γ‐TiAl joint brazed at 1230 °C is γ‐TiAl/Ti3Al + Al3NiTi2 (layer I)/Al3NiTi2 + Ti3Al (layer II)/Al3NiTi2 + TiB + Ti3Al (layer III)/Al3NiTi2 + Ti3Al (layer II)/Ti3Al + Al3NiTi2 (layer I)/γ‐TiAl. The layer II containing high‐hardness Al3NiTi2 is always the weakest part in the brazed joint. The microstructure refinement and load‐bearing behavior of layer III are increased with brazing temperature due to the increasing length of the TiB whisker. Variation of the content of low‐hardness Ti3Al in layer II as well as its microstructure refinement and internal bonding strength, the shear strength of γ‐TiAl joints is first increased and then decreased with brazing temperature, but that of Al3NiTi2 in layer II is reversed. The joint brazed at 1230 °C possesses the maximum shear strength of 332.87 MPa and a quasi‐cleavage fracture occurs in the layer II mainly consisted of Al3NiTi2.

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Section: Typical Interfacial Microstructure Of γ-Tial-brazed Jointssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler

Li,

Yuan,

Luo

et al. 2023

Adv Eng Mater

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“…At elevated temperatures, interdiffusion of elements between the substrate and coating can lead to significant structural and composition changes resulting in deterioration of oxidation resistance. For this reason, coatings with an elemental composition close to that of the substrate are more preferable; for example, PVD TiAl coatings on TNM alloys [28,29]. In addition, the Al amount in thin coatings required to ensure the formation of aluminum oxide is limited during long-term operation [30].…”

Section: Introductionmentioning

confidence: 99%

TiAl-Based Oxidation-Resistant Hard Coatings with Different Al Contents Obtained by Vacuum-Pulse-Arc Granule Melting

Sheveyko,

Kuptsov,

Kiryukhantsev-Korneev

et al. 2023

Coatings

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A method was proposed for increasing the oxidation resistance of promising wrought Ti2AlNb ortho-alloys by depositing γ-TiAl-based coatings. Using original vacuum pulse-arc melting of 100 μm thick granule layers, coatings with different Al/Ti ratios and a thickness of 50–60 µm were obtained on the surface of the Ti50Al25Nb25 alloy. Granules Ti50Al44Nb4.9Mo1B0.1 (at.%), 20–60 μm in size, were employed. To vary Al content, initial granules and their mixture with Al powder were used. Excellent adhesion of the coatings is ensured by the similar chemical composition and structure of the substrate and coatings, as well as micro-metallurgical reactions between granules and the substrate that occur during treatment. The resulting coatings had a submicron gradient structure consisting of TiAl and Ti3Al intermetallic compounds. During oxidation at 850 °C for 10 h, an oxide layer consisting of a mixture of α-Al2O3, TiO2, and AlNbO4 was formed on the coating surfaces. With an increase in the annealing duration to 100 h, a dense α-Al2O3 oxide layer, approximately 0.5 µm thick, was formed over the primary oxide mixture, the quality of which was higher in coatings enriched with aluminum.

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“…Traditional methods to fabricate Ti-Al composites include rolling (Luo and Acoff, 2006), welding (Chen, Zhang, et al , 2020) and physical vapor deposition (Kagerer et al , 2022), whereas these manufacturing methods have long process or stress concentration. Laser based directed energy deposition (L-DED) is an important research direction of laser additive manufacturing technology, which is one of the most promising and fastest developing material processing technologies (Thomas et al , 2020).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Additive manufacturing of Ti-Al functionally graded material by laser based directed energy deposition

Chen

Wang

et al. 2022

RPJ

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Purpose Ti-Al composite plates have been used in aerospace and other important fields for specific purposes in recent years. However, relatively few studies have concentrated on Ti-Al additive manufacturing because during additive manufacturing process the local fusion and mixing of Ti/Al are inevitable. These areas where Ti and Al are mixed locally, especially interface, could easily generate high residual stresses and cracks. This study aims to manufacture Ti-Al functionally graded material and investigate the interaction of interface. Design/methodology/approach In this study, Ti6Al4V/AlSi10Mg functionally graded materials were fabricated by laser based directed energy deposition (L-DED) and a strategy using V interlayer to relieve interfacial stress was investigated. Findings The area between the two materials was divided into transition zone (TZ) and remelting zone (RZ). The phase distribution, microstructure and micro-Vickers hardness of the TZ and RZ were investigated. Typical intermetallic compounds (IMCs) such as TiAl3, Ti3Al and Ti5Si3 were found in both composites. The addition of V interlayer promoted the homogenization of IMCs near interface and led to the formation of new phases like V5Si3 and Al3V. Originality/value The solidification process near the interface of Ti-Al functionally graded material and the possible generation of different phases were described. The result of this paper proved the feasibility of manufacturing Ti-Al functionally graded material by L-DED.

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TGO formation and oxygen diffusion in Al-rich gamma-TiAl PVD-coatings on TNM alloys

Cited by 10 publications

References 29 publications

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler

TiAl-Based Oxidation-Resistant Hard Coatings with Different Al Contents Obtained by Vacuum-Pulse-Arc Granule Melting

Additive manufacturing of Ti-Al functionally graded material by laser based directed energy deposition

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TGO formation and oxygen diffusion in Al-rich gamma-TiAl PVD-coatings on TNM alloys

Cited by 10 publications

References 29 publications

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH2–Ni–TiB2 Powder Filler

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH2–Ni–TiB2 Powder Filler

TiAl-Based Oxidation-Resistant Hard Coatings with Different Al Contents Obtained by Vacuum-Pulse-Arc Granule Melting

Additive manufacturing of Ti-Al functionally graded material by laser based directed energy deposition

Contact Info

Product

Resources

About

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler

Microstructure Evolution and Shear Strength of TiAl‐Based Intermetallics Joint Vacuum Brazed with TiH₂–Ni–TiB₂ Powder Filler