The effect of heat treatment sequence on microstructure and mechanical properties of diffusion brazed IN-939 superalloy

Arhami, Farzam; Mirsalehi, Seyyed Ehsan

doi:10.1016/j.jmatprotec.2018.11.020

Cited by 30 publications

(7 citation statements)

References 36 publications

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“…Z Miskovic et al [26]showed that for as cast IN 939 alloy dendrites are rich in Ni, Co, and Cr while interdendritic areas are rich in Ti, Nb, Ta. Similarly, F. Arhami et al [27] showed that the microstructure of IN 939 consists of γ/γ' matrix and primary carbide phases which was rich in Ti, Nb and Ta. In Fig.…”

Section: Isothermal Oxidation Kinetics Of In939 Alloysmentioning

confidence: 90%

Comparison of Isothermal Oxidation Performance of IN 939 Produced by Casting and Additive Manufacturing

Başbozkurt,

Sarıoğlu

2023

Preprint

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The focus of this study is to compare the isothermal oxidation behavior of IN 939 nickel-based superalloys manufactured by powder bed fusion (PBF) and casting methods. Oxidation experiments were performed on heat treated and non-heat treated IN 939 specimens to reveal the role of heat treatment and manufacturing methods on oxidation behavior. Microstructure of as cast IN 939 had a dendritic structure with gamma prime precipitates. After heat treatment two kinds of gamma prime precipitates were visible. IN 939 manufactured by Powder bed fusion exhibited clearly visible melt pools and no trace of gamma prime precipitates. After heat treatment the melt pools disappeared, and gamma prime precipitates formed. Weight gain results showed that all samples experienced similar mass gain characteristics however, PBF IN 939 with heat treatment showed slightly superior spallation behavior than other samples at 1000˚C. Spallation did not occur at 800 and 900˚C whereas at 1000˚C all samples experienced spallation. All samples followed a parabolic rate law. The activation energies of all samples, calculated for three temperatures (800, 900 and 1000˚C,) were similar, ranging between 260.99-287.51 kJ/mole. XRD and EDS analyses were performed to investigate the oxidation products on the surface. Results indicated that the oxide scale that formed on all IN 939 samples were mainly Cr2O3 and TiO2 in rutile form. In conclusion, based on oxidation weight gain (kinetics) results and oxide scale analysis, additively manufactured IN939 superalloys showed similar oxidation resistance compared to as cast IN939 alloy. These results supported the replacement of as cast manufacturing technique with additive manufacturing techniques for IN 939 alloys with respect to high temperature oxidation resistance.

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Section: Isothermal Oxidation Kinetics Of In939 Alloysmentioning

confidence: 90%

Comparison of Isothermal Oxidation Performance of IN 939 Produced by Casting and Additive Manufacturing

Başbozkurt,

Sarıoğlu

2023

Preprint

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“…718Plus and Ni 3 Al-based superalloys are shown on the left and right, respectively. As can be seen in Figure 3a-c, the joints can be divided into three regions: [35,36] diffusion-affected zone (DAZ) on both sides shows different morphologies of precipitation, and the amount of precipitation decreases gradually from the joint toward the base metal; isothermally solidified zone (ISZ) consists of pre-eutectic γ solid solution, nucleation, and growth of grains from the base metal to the center of the joint; athermally solidified zone (ASZ), when holding time is insufficient, residual liquid phase forms eutectic phase by athermal solidification.…”

Section: Microstructure Of Tlp Jointmentioning

confidence: 99%

Effect of Holding Time on Microstructure and Mechanical Properties of Dissimilar γ'‐Strengthened Superalloys TLP Joint

Yang

Ding

Wang³

et al. 2023

Adv Eng Mater

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To achieve efficient connectivity of dissimilar γ'‐strengthened superalloy, transient liquid‐phase (TLP) diffusion bonding of 718Plus and Ni3Al‐based superalloys is carried out using BNi‐2 interlayer at a constant temperature of 1100 °C with holding times of 3, 15, 30, and 60 min. It is shown in the results that when the holding time is insufficient, isothermal solidification transforms into athermal solidification. Due to the enrichment of B and Cr elements in liquid phase, ternary eutectic consisting of γ, Ni3B, and CrB is formed at the joint center. Ternary eutectic with higher hardness (≈600 Hv) is poorly bonded to the matrix, which can easily become crack initiation location and significantly deteriorated the tensile properties. In addition, microhardness of the joint becomes more uniform and tensile strength gradually increases due to the reduction of eutectic with holding time increasing. Isothermal solidification completes and a joint without eutectic structure is formed at 1100 °C for 60 min. Diffusion of Al atoms leads to the formation of γ' with gradient size and tensile strength is comparable to that of base metal which is about 690.93 MPa.

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“…This is called isothermal solidification, which is more convenient than solidification by cooling [11,12,21,[13][14][15][16][17][18][19][20]. In previous studies, similar and dissimilar TLP bonding of several Ni-based superalloys such as IN-617 [22][23][24][25], IN-939 [16,[26][27][28],…”

Section: Introductionmentioning

confidence: 99%

Dissimilar transient liquid phase bonding of Ti-6Al-4V alloy to Inconel 625 superalloy: Effect of bonding temperature on microstructural evolutions and mechanical properties

Zorriatolhosseini,

Mirsalehi,

Shamsi

2023

Preprint

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The present study investigated the effect of bonding temperature on the dissimilar transient liquid phase (TLP) bonded IN-625/Ti-6Al-4V dissimilar joints using a thin foil of pure copper as the interlayer. The samples were bonded in a vacuum chamber at 900, 930, and 960°C for 60 min. The results indicated the occurrence of different intermetallic compounds such as Ti2Cu, TiCu2, TiCu, NiTi, and Ni3Ti at different bonding temperatures, and it was concluded that in all the samples, isothermal solidification was accomplished. Maximum shear strength of 278 MPa was achieved at 930 ℃. At lower bonding temperatures, the presence of porosities and cracks decreases the shear strength. At higher temperatures, a high-volume percentage of intermetallic compounds embrittled the specimen and reduced its shear strength. The results of scanning electron microscopy of the fracture surfaces revealed the formation of extensive cleavage fracture and river-like patterns in all samples, indicating a brittle failure mode.

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The effect of heat treatment sequence on microstructure and mechanical properties of diffusion brazed IN-939 superalloy

Cited by 30 publications

References 36 publications

Comparison of Isothermal Oxidation Performance of IN 939 Produced by Casting and Additive Manufacturing

Comparison of Isothermal Oxidation Performance of IN 939 Produced by Casting and Additive Manufacturing

Effect of Holding Time on Microstructure and Mechanical Properties of Dissimilar γ'‐Strengthened Superalloys TLP Joint

Dissimilar transient liquid phase bonding of Ti-6Al-4V alloy to Inconel 625 superalloy: Effect of bonding temperature on microstructural evolutions and mechanical properties

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