Advances in Secondary Phase Evolution and Performance Enhancement of Allvac 718Plus Superalloy
TANG Liting, GUO Qianying, LI Chong, DING Ran, LIU Yongchang()
School of Materials Science and Engineering, Tianjin University, Tianjin 300354, China
Cite this article:
TANG Liting, GUO Qianying, LI Chong, DING Ran, LIU Yongchang. Advances in Secondary Phase Evolution and Performance Enhancement of Allvac 718Plus Superalloy. Acta Metall Sin, 2025, 61(1): 43-58.
Allvac 718Plus is a newly developed nickel-based superalloy derived from Inconel 718 alloy via composition optimization. Its maximum service temperature is approximately 55 oC higher than that of Inconel 718. With its excellent combination of creep resistance, fatigue resistance, machinability, and weldability, the Allvac 718Plus is highly suitable for manufacturing high-temperature components that can operate at up to 700 oC. As a precipitation-strengthened superalloy that is relatively new with limited application history, understanding the evolution of its secondary phases during heat treatment is crucial for optimizing its properties via microstructure control. In this context, the secondary phases found in Allvac 718Plus are introduced, including the primary strengthening γ′ phase, the main grain-boundary η phase, and the γ″, δ, σ, and C14 Laves phases that form under specific conditions. The precipitation behaviors of the γ′ and η phases during standard heat treatments are examined, along with the effects of presolidification and direct aging treatments. Additionally, the evolution of secondary phases during prolonged thermal exposure are explored. The results demonstrate that the formation of a more stable composite γ″-γ′ structure is a promising strategy to achieve long-term serviceability for the alloy. The influence of the microstructural evolution of secondary phases during high-temperature service on fatigue and creep resistance is also analyzed, focusing on the roles of the two primary secondary phases. Furthermore, this paper highlights the correlation between the sluggish kinetics of γ′ phase precipitation in Allvac 718Plus and its weldability. A comprehensive overview of the harmful effects of the Laves and η phases on cracking during welding and strain-age cracking is also provided.
Table 1 Crystal structures and compositions of main phases in Allvac 718Plus alloy[4,18-22]
Fig.1 Crystallographic prototype structures of the γ′ (a) and η (b) phases in Allvac 718Plus alloy
Fig.2 Crystallographic prototypes structures of the two topological closed-packed (TCP) phases in Allvac 718Plus alloy[18] (a) σ phase (b) Laves phase
Fig.3 TEM-EDS mapping results of the Laves phase (a, b)[34] and σ phase (c, d) in Allvac 718Plus alloy
Fig.4 SEM images of the grain-boundary η phase with different morphologies and the serrated boundary induced by needle-like η phase in Allvac 718Plus solution treated for 1 h at 1000 oC (a, b) and 920 oC (c, d), respectively, followed by the dual aging treatment (The yellow arrows denote the growth directions of the granular η phase)[10]
Fig.5 Schematics of the evolution of secondary phases in rapidly-solidified Allvac 718Plus alloy during solution treatment at 960 oC for 1 h (a), 6 h (b), 8 h (c), 14 h (d), and 24 h (e) (The secondary phases consist of the η phase, the MC carbides, and the Laves (C14) phase)[34]
Heat treatment
Vicker's hardness / HV
Equivalent pressure / GPa
Single aged (788 oC, 4 h, air cooling)
466.8 ± 11.8
4.58 ± 0.12
Double aged (788 oC, 4 h, water cooling + 675 oC, 8 h, air cooling)
526.30 ± 11.2
5.16 ± 0.11
Table 2 Vickers microhardnesses and equivalent maximum pressures as measured for single and double aged Allvac 718Plus alloys[46]
State of Allvac 718Plus alloy
704 oC
760 oC
Rapidly-solidified
14.4
83.2
Forged
08.7
64.4
Table 3 Coarsening rates of γ′ phase of the rapidly-solidified and forged Allvac 718Plus alloy at 704 and 760 oC[29]
Fig.6 TEM images showing the γ″/γ′ co-precipitates in the rapidly-solidified Allvac 718Plus alloy after long-term thermal exposure for 50 h (a, d), 200 h (b, e), and 1000 h (c, f)[29] (a-c) 704 oC (d-f) 760 oC
Fig.7 Bright-field TEM image showing the η phase, δ phase, and σ phase in the rapidly-solidified Allvac 718Plus alloy after the thermal exposures of 760 oC for 1000 h (a), the corresponding selected area electron diffraction (SAED) patterns (b, c), elemental maps images (d), and elemental line-scanning results from TEM-EDS spectrum (e)[29]
Heat treatment
γ′ size
VF of σ
25 oC
704 oC
nm
%
YS / MPa
UTS / MPa
El / %
YS / MPa
UTS / MPa
El / %
As-cast
35.5 ± 6.7
-
1156.48
1493.14
14.53
953.02
1069.00
15.23
704 oC, 100 h
35.6 ± 6.8
-
1247.95
1614.82
14.35
987.05
1124.90
16.61
704 oC, 200 h
36.5 ± 7.2
-
1236.30
1611.22
14.44
988.90
1126.05
11.57
704 oC, 500 h
39.9 ± 7.3
0.36
1217.46
1594.99
13.81
981.76
1104.97
19.34
704 oC, 1000 h
47.5 ± 8.8
1.97
1224.04
1581.43
11.78
969.42
1072.54
21.09
760 oC, 100 h
50.1 ± 8.7
-
1035.34
1410.07
17.58
848.89
0956.40
18.62
760 oC, 200 h
53.8 ± 10.6
1.14
1014.98
1384.67
13.93
806.55
0927.82
24.82
760 oC, 500 h
65.7 ± 13.9
2.63
0967.70
1346.90
11.38
766.01
0855.39
22.93
760 oC, 1000 h
83.6 ± 18.8
3.82
0855.11
1236.68
07.60
748.99
0874.90
30.35
Table 4 Microstructure information and corresponding room-temperatures (25 oC) and high-temperature (704 oC) tensile properties of forged Allvac 718Plus alloy after long-term thermal exposures at 704 and 760 oC[38]
Fig.8 Schematics showing the tensile precipitation-strengthened mechanisms at room temperature (a, b) and elevated temperature (c, d) of the forged Allvac 718Plus alloy after the long-term thermal exposures of 704 oC, 100 h (a, c) and 760 oC, 1000 h (b, d) samples[38]
Fig.9 A qualitative model schematic illustration directly showing the evolution of γ″/γ′ coprecipitates[28] (a) all evolution process in forged Allvac 718Plus alloy during long-term thermal exposures at 705 oC (b) the evolution from γ′ to sandwich-γ″/γ′/γ″ coprecipitates (c) the evolution from sandwich-γ″/γ′/γ″ coprecipitates to partly compact-γ″/γ′ coprecipitates (d) the evolution from sandwich-γ″/γ′/γ″ coprecipitates and partly compact-γ″/γ′ coprecipitates to all compact-γ″/γ′/γ″ coprecipitates
1
Du J H, Bi Z N, Qu J L. Recent development of triple melt GH4169 alloy[J]. Acta Metall. Sin., 2023, 59: 1159
doi: 10.11900/0412.1961.2023.00144
Zhang J, Wang L, Xie G, et al. Recent progress in research and development of nickel based single crystal superalloys[J]. Acta Metall. Sin., 2023, 59: 1109
Wu J, Liu Y C, Li C, et al. Recent progress of microstructure evolution and performance of multiphase Ni3Al-based intermetallic alloy with high Fe and Cr contents[J]. Acta Metall. Sin., 2020, 56: 21
doi: 10.11900/0412.1961.2019.00137
Liu Y C, Zhang H J, Guo Q Y, et al. Microstructure evolution of Inconel 718 superalloy during hot working and its recent development tendency[J]. Acta Metall. Sin., 2018, 54: 1653
doi: 10.11900/0412.1961.2018.00340
Du J H, Lv X D, Dong J X, et al. Research progress of wrought superalloys in China[J]. Acta Metall. Sin., 2019, 55: 1115
doi: 10.11900/0412.1961.2019.00142
Qiao Z, Li C, Zhang H J, et al. Evaluation on elevated-temperature stability of modified 718-type alloys with varied phase configurations[J]. Int. J. Min. Met. Mater., 2020, 27: 1123
doi: 10.1007/s12613-019-1949-8
8
Wu Y T, Li C, Xia X C, et al. Precipitate coarsening and its effects on the hot deformation behavior of the recently developed γ'- strengthened superalloys[J]. J. Mater. Sci. Technol., 2021, 67: 95
9
Qi Q Q, Zhang H J, Liu C X, et al. On the microstructure evolution during low cycle fatigue deformation of wrought ATI 718Plus alloy[J]. Mater. Sci. Eng., 2020, A798: 140132
10
Tang L T, Zhang H Y, Guo Q Y, et al. The precipitation of η phase during the solution treatments of Allvac 718Plus[J]. Mater. Charact., 2021, 176: 111142
11
Li L H, Dong J X, Zhang M C, et al. Integrated simulation of the forging process for GH4738 alloy turbine disk and its application[J]. Acta Metall. Sin., 2014, 50: 821
doi: 10.3724/SP.J.1037.2013.00675
Li J, Wu Y T, Liu Y C, et al. Enhancing tensile properties of wrought Ni-based superalloy ATI 718Plus at elevated temperature via morphology control of η phase[J]. Mater. Charact., 2020, 169: 110547
13
Guo Q Y, Ji K K, Zhang T, et al. Precipitates evolution and tensile behavior of wrought Ni-based ATI 718Plus superalloy during long-term thermal exposure[J]. Sci. China Technol. Sci., 2022, 65: 1283
14
Wang M Q, Deng Q, Du J H, et al. Research progress of alloy ATI 718Plus in China[J]. Rare Met. Mater. Eng., 2016, 45: 3335
Kumar K S, Hazzledine P M. Polytypic transformations in Laves phases[J]. Intermetallics, 2004, 12: 763
16
Asala G, Khan A K, Andersson J, et al. Microstructural analyses of ATI 718Plus® produced by wire-ARC additive manufacturing process[J]. Metall. Mater. Trans., 2017, 48A: 4211
17
Chen Y H, Yang C L, Fan C L, et al. The influence of solution temperature on microstructure evolution and mechanical properties of ATI 718Plus repaired by wire and arc additive manufacturing[J]. Mater. Sci. Eng., 2022, A852: 143641
18
Krakow R, Johnstone D N, Eggeman A S, et al. On the crystallography and composition of topologically close-packed phases in ATI 718Plus® [J]. Acta Mater., 2017, 130: 271
19
Pickering E J, Mathur H, Bhowmik A, et al. Grain-boundary precipitation in Allvac 718Plus[J]. Acta Mater., 2012, 60: 2757
20
Eurich N C, Bristowe P D. Thermodynamic stability and electronic structure of η-Ni6Nb(Al, Ti) from first principles[J]. Scr. Mater., 2014, 77: 37
21
Shen Y, Wang M Q, Xia H, et al. Pseudobinary phase diagrams of eutectic reaction for Pt-containing and Pt-free 718Plus alloys[J]. Adv. Eng. Mater., 2021, 23: 2001233
22
Hosseini S A, Abbasi S M, Madar K Z, et al. The effect of boron and zirconium on wrought structure and γ-γ′ lattice misfit characterization in nickel-based superalloy ATI 718Plus[J]. Mater. Chem. Phys., 2018, 211: 302
23
Srinivasan D, Lawless L U, Ott E A. Experimental determination of TTT diagram for alloy 718Plus®[A]. Superalloys 2012[M]. Seven Springs: TMS, 2012: 759
24
Wang M Q, Tian C G, Nan Y, et al. A review on 718Plus, the new superalloy: Performance, aerospace application and development trend[J]. Mater. Rev., 2017, 31(19): 72
Zhang H J, Li C, Liu Y C, et al. Precipitation behavior during high-temperature isothermal compressive deformation of Inconel 718 alloy[J]. Mater. Sci. Eng., 2016, A677: 515
26
Hausmann D, Förner A, Pröbstle M, et al. Correlation between local chemical composition and formation of different types of ordered phases in the polycrystalline nickel-base superalloy A718Plus[J]. Adv. Eng. Mater., 2021, 23: 2100558
27
Asala G, Andersson J, Ojo O A. Precipitation behavior of γ′ precipitates in the fusion zone of TIG welded ATI 718Plus® [J]. Int. J. Adv. Manuf. Technol., 2016, 87: 2721
28
Guo Q Y, Ma Z Q, Qiao Z X, et al. A new type-γ′/γ′′ coprecipitation behavior and its evolution mechanism in wrought Ni-based ATI 718Plus superalloy[J]. J. Mater. Sci. Technol., 2022, 119: 98
29
Tang L T, Guo Q Y, Li C, et al. Precipitation behaviors of the rapidly-solidified Allvac 718Plus superalloy during aging treatment[J]. Mater. Charact., 2023, 200: 112856
30
Xie X S, Wang G L, Dong J X, et al. Structure stability study on a newly developed nickel-base superalloy-Allvac® 718Plus™[A]. Superalloys 718, 625, 706 and Derivatives 2005[M]. Pittsburgh: TMS, 2005: 179
31
Wang M Q, Du J H, Deng Q, et al. Effect of the precipitation of the η-Ni3Al0.5Nb0.5 phase on the microstructure and mechanical properties of ATI 718Plus[J]. J. Alloys Compd., 2017, 701: 635
32
Casanova A, Martín-Piris N, Hardy M, et al. Evolution of secondary phases in alloy ATI 718Plus® during processing[A]. Proceedings of MATEC Web of Conferences[C]. Paris: EDP Sciences, 2014: 09003
33
Messé O M, Barnard J S, Pickering E J, et al. On the precipitation of delta phase in ALLVAC® 718Plus[J]. Philos. Mag., 2014, 94: 1132
34
Tang L T, Guo Q Y, Li C, et al. Precipitation sequences in rapidly solidified Allvac 718Plus alloy during solution treatment[J]. J. Mater. Sci. Technol., 2022, 128: 180
doi: 10.1016/j.jmst.2022.03.031
35
Asala G, Andersson J, Ojo O A. Improved dynamic impact behaviour of wire-arc additive manufactured ATI 718Plus® [J]. Mater. Sci. Eng., 2018, A738: 111
36
Andersson J, Sjöberg G, Viskari L, et al. Hot cracking of Allvac 718Plus, Alloy 718 and Waspaloy at varestraint testing[A]. Proceedings of the 47th Conference of Metallurgists (COM)[C]. Winnipeg: Springer, 2008: 401
37
Kruk A, Cempura G. Application of analytical electron microscopy and FIB-SEM tomographic technique for phase analysis in as-cast Allvac 718Plus superalloy[J]. Int. J. Mater. Res., 2019, 110: 3
38
Tang L T, Guo Q Y, Li C, et al. Precipitation and tensile behaviors of Allvac 718Plus superalloy during long-term thermal exposure[J]. Mater. Sci. Eng., 2024, A896: 146221
39
Wang M Q, Deng Q, Du J H, et al. The effect of Aluminum on microstructure and mechanical properties of ATI 718Plus alloy[J]. Mater. Trans., 2015, 56: 635
40
Kumari G, Boehlert C, Sankaran S, et al. The effects of solutionizing temperature on the microstructure of Allvac 718Plus[J]. J. Mater. Eng. Perform., 2020, 29: 3523
doi: 10.1007/s11665-020-04687-z
41
Wang M Q, Deng Q, Du J H, et al. The influence of Δ phase on mechanical properties of ATI 718Plus alloy[A]. Proceedings of the 8th International Symposium on Superalloy 718 and Derivatives[C]. Pittsburgh: TMS, 2014: 769
42
Lech S, Wusatowska-Sarnek A M, Wieczerzak K, et al. Evolution of microstructure and mechanical properties of ATI 718Plus® superalloy after graded solution treatment[J]. Metall. Mater. Trans., 2023, 54: 2011
43
Whitmore L, Ahmadi M R, Guetaz L, et al. The microstructure of heat-treated nickel-based superalloy 718Plus[J]. Mater. Sci. Eng., 2014, A610: 39
44
Li J, Ding R, Guo Q Y, et al. Effect of solution cooling rate on microstructure evolution and mechanical properties of Ni-based superalloy ATI 718Plus[J]. Mater. Sci. Eng., 2021, A812: 141113
45
Whitmore L, Ahmadi M R, Stockinger M, et al. Microstructural investigation of thermally aged nickel-based superalloy 718Plus[J]. Mater. Sci. Eng., 2014, A594: 253
46
Whitmore L, Leitner H, Povoden-Karadeniz E, et al. Transmission electron microscopy of single and double aged 718Plus superalloy[J]. Mater. Sci. Eng., 2012, A534: 413
47
Cao W D, Kennedy R L. Application of direct aging to Allvac® 718Plus™ alloy for improved performance[A]. Superalloys 718, 625, 706 and Derivatives 2005[M]. Pittsburgh: TMS, 2005: 213
48
Lech S, Kruk A, Cempura G, et al. Influence of high-temperature exposure on the microstructure of ATI 718Plus superalloy studied by electron microscopy and tomography techniques[J]. J. Mater. Eng. Perform., 2020, 29: 1453
49
Hörnqvist M, Viskari L. Reduced dwell-fatigue resistance in a Ni-base superalloy after short-term thermal exposure[J]. Metall. Mater. Trans., 2014, 45A: 2699
50
Pröbstle M, Neumeier S, Hünert D, et al. Tensile and creep strength of thermally exposed allvac 718Plus[A]. Proceedings of the 8th International Symposium on Superalloy 718 and Derivatives[C]. Pittsburgh: TMS, 2014: 349
51
Kearsey R M, Tsang J, Oppenheimer S, et al. Microstructural effects on the mechanical properties of ATI 718Plus® alloy[J]. JOM, 2012, 64: 241
52
Tsang J, Kearsey R M, Au P, et al. Effect of composition and microstructure on the fatigue and creep-fatigue behaviour of Allvac 718Plus alloy[J]. Mater. High Temp., 2010, 27: 79
53
Liu X B, Xu J, Barbero E, et al. Effect of thermal treatment on the fatigue crack propagation behavior of a new Ni-base superalloy[J]. Mater. Sci. Eng., 2008, A474: 30
54
Cao W D. Thermal stability characterization of Ni-base ATI 718Plus® superalloy[A]. Superalloys 2008[M]. Pittsburgh: TMS, 2008: 789
55
Dash B B, Dixit S, Boehlert C J, et al. Influence of interrupted ageing on the temporal evolution of the γ′ size distribution and the co-precipitation of γ″ in alloy 718Plus[J]. Mater. Charact., 2023, 206: 113394
56
Guo J T. The effect of aluminium and titanium on the microstructure and mechanical properties of an iron-base alloy[J]. Acta. Metall. Sin., 1978, 14: 227
Viskari L, Cao Y, Norell M, et al. Grain boundary microstructure and fatigue crack growth in Allvac 718Plus superalloy[J]. Mater. Sci. Eng., 2011, A528: 2570
58
Wang M, Du J, Deng Q, et al. The effect of grain size on the dwell fatigue crack growth rate of alloy ATI 718Plus®[A]. Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications[C]. Cham: Springer, 2018: 817
59
Kirchmayer A, Pröbstle M, Huenert D, et al. Influence of grain size and volume fraction of η/δ precipitates on the dwell fatigue crack propagation rate and creep resistance of the nickel-base superalloy ATI 718Plus[J]. Metall. Mater. Trans., 2023, 54A: 2219
60
Liu X B, Xu J, Deem N, et al. Effect of thermal-mechanical treatment on the fatigue crack propagation behavior of newly developed Allvac® 718PlusTM alloy[A]. Superalloys 718, 625, 706 and Derivatives 2005[M]. Pittsburgh: TMS, 2005: 233
61
Tsang J, Kearsey R M, Au P, et al. Microstructural study of fatigue and dwell fatigue crack growth behaviour of ATI 718Plus alloy[J]. Can. Metall. Q., 2011, 50: 222
62
Kattoura M, Mannava S R, Qian D, et al. Effect of ultrasonic nanocrystal surface modification on elevated temperature residual stress, microstructure, and fatigue behavior of ATI 718Plus alloy[J]. Int. J. Fatigue, 2018, 110: 186
63
Kattoura M, Telang A, Mannava S R, et al. Effect of ultrasonic nanocrystal surface modification on residual stress, microstructure and fatigue behavior of ATI 718Plus alloy[J]. Mater. Sci. Eng., 2018, A711: 364
64
Kattoura M, Mannava S R, Qian D, et al. Effect of laser shock peening on elevated temperature residual stress, microstructure and fatigue behavior of ATI 718Plus alloy[J]. Int. J. Fatigue, 2017, 104: 366
65
Kattoura M, Mannava S R, Qian D, et al. Effect of laser shock peening on residual stress, microstructure and fatigue behavior of ATI 718Plus alloy[J]. Int. J. Fatigue, 2017, 102: 121
66
Zrník J, Strunz P, Horňák P, et al. Microstructural changes in long-time thermally exposed Ni-base superalloy studied by SANS[J]. Appl. Phys., 2002, 74A: s1155
67
Chen K, Dong J X, Yao Z H, et al. Creep performance and damage mechanism for Allvac 718Plus superalloy[J]. Mater. Sci. Eng., 2018, A738: 308
68
Hayes R W, Unocic R R, Nasrollahzadeh M. Creep deformation of Allvac 718Plus[J]. Metall. Mater. Trans., 2015, 46A: 218
69
Barba D, Pedrazzini S, Vilalta-Clemente A, et al. On the composition of microtwins in a single crystal nickel-based superalloy[J]. Scr. Mater., 2017, 127: 37
70
Unocic R R, Zhou N, Kovarik L, et al. Dislocation decorrelation and relationship to deformation microtwins during creep of a gamma' precipitate strengthened Ni-based superalloy[J]. Acta Mater., 2011, 59: 7325
71
Alabbad B, Tin S. Effect of grain boundary misorientation on η phase precipitation in Ni-base superalloy 718Plus[J]. Mater. Charact., 2019, 151: 53
doi: 10.1016/j.matchar.2019.02.038
72
Hassan B, Corney J. Grain boundary precipitation in Inconel 718 and ATI 718Plus[J]. Mater. Sci. Technol., 2017, 33: 1879
73
Unocic K A, Hayes R W, Mills M J, et al. Microstructural features leading to enhanced resistance to grain boundary creep cracking in Allvac 718Plus[J]. Metall. Mater. Trans., 2010, 41A: 409
74
Zhang H J, Li C, Guo Q Y, et al. Improving creep resistance of nickel-based superalloy Inconel 718 by tailoring gamma double prime variants[J]. Scr. Mater., 2019, 164: 66
75
Huang C A, Wang T H, Lee C H, et al. A study of the heat-affected zone (HAZ) of an Inconel 718 sheet welded with electron-beam welding (EBW)[J]. Mater. Sci. Eng., 2005, A398: 275
76
Asala G, Ojo O A. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus[J]. Results Phys., 2016, 6: 196
77
Andersson J, Sjöberg G P. Repair welding of wrought superalloys: Alloy 718, Allvac 718Plus and Waspaloy[J]. Sci. Technol. Weld. Joining, 2012, 17: 49
78
Devendranath Ramkumar K, Sridhar R, Periwal S, et al. Investigations on the structure-property relationships of electron beam welded Inconel 625 and UNS 32205[J]. Mater. Des., 2015, 68: 158
79
Koleva E G, Mladenov G M, Trushnikov D N, et al. Signal emitted from plasma during electron-beam welding with deflection oscillations of the beam[J]. J. Mater. Process. Technol., 2014, 214: 1812
80
Vishwakarma K R, Richards N L, Chaturvedi M C. Microstructural analysis of fusion and heat affected zones in electron beam welded Allvac® 718PlusTM superalloy[J]. Mater. Sci. Eng., 2008, A480: 517
81
Idowu O A. Heat affected zone cracking of Allvac 718Plus superalloy during high power beam welding and post-weld heat treatment[D]. Winnipeg: The University of Manitoba, 2010
82
Singh S, Fransson W, Andersson J, et al. Varestraint weldability testing of ATI 718Plus®-influence of eta phase[A]. Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications[C]. New York: Springer, 2018: 929
83
Mei Y P, Liu Y C, Liu C X, et al. Effect of base metal and welding speed on fusion zone microstructure and HAZ hot-cracking of electron-beam welded Inconel 718[J]. Mater. Des., 2016, 89: 964
84
Singh S, Andersson J. Varestraint weldability testing of cast ATI® 718Plus™: A comparison to cast alloy 718[J]. Weld World, 2019, 63: 389
85
Hanning F, Khan A K, Andersson J, et al. Advanced microstructural characterisation of cast ATI 718Plus®-effect of homogenisation heat treatments on secondary phases and repair welding behaviour[J]. Weld World, 2020, 64: 523
doi: 10.1007/s40194-020-00851-0
86
Hanning F, Andersson J. The influence of base metal microstructure on weld cracking in manually GTA repair welded cast ATI 718Plus® [A]. Proceedings of the 9th International Symposium on Superalloy 718 & Derivatives: Energy, Aerospace, and Industrial Applications[C]. Cham: Springer, 2018: 917
87
Andersson J, Sjöberg G, Larsson J. Investigation of homogenization and its influence on the repair welding of cast Allvac 718Plus(®)[A]. Superalloy 718 and Derivatives[M]. Pittsburgh: TMS, 2010: 439
88
Andersson J, Sjöberg G, Hänninen H. Metallurgical response of electron beam welded Allvac® 718Plus™[A]. Hot Cracking Phenomena in Welds III[M]. Berlin, Heidelberg: Springer, 2011: 415
89
Idowu O A, Ojo O A, Chaturvedi M C. Crack-free electron beam welding of Allvac 718Plus®superalloy[J]. Weld. J., 2009, 88: 179S