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Acta Metall Sin  2020, Vol. 56 Issue (9): 1195-1205    DOI: 10.11900/0412.1961.2020.00020
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Effects of Hot Isostatic Pressure on Microdefects and Stress Rupture Life of Second-Generation Nickel-Based Single Crystal Superalloy in As-Cast and As-Solid-Solution States
HE Siliang1, ZHAO Yunsong2, LU Fan1, ZHANG Jian2, LI Longfei1(), FENG Qiang1
1 Beijing Innovation Center for Materials Genome Engineering, State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
2 Science and Technology on Advanced High Temperature Structural Materials Laboratory, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China
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Abstract  

Due to the excellent high temperature comprehensive performance and cost effective, the second-generation nickel-based single crystal superalloy has been widely used in the high-pressure turbine blades of advanced aero-engines. Microdefects such as micropores and interdendritic eutectic are seriously harmful to the high temperature mechanical properties of nickel-based single crystal superalloys. Hot isostatic pressure (HIP) technology, which has been widely used in powder and casting superalloys, can effectively reduce the micropores, interdendritic eutectic and other structural defects formed in the turbine blades during manufacturing, and improve the service reliability of turbine blades. However, the effect of HIP process on the high temperature stress rupture life of nickel-based single crystal superalloys is still controversial, especially with regard to the initial microstructure state of the nickel-based single crystal superalloys, i.e. the as-cast microstructure state or the as-solid-solution state. In this work, a kind of second-generation nickel-based single crystal superalloy with as-cast state or as-solid-solution state was selected as the research object. Through two-stage heat/booster type heat treatment process, in combination with microdefects quantitative analysis, quantitative characterization of alloying element segregation and high temperature stress rupture tests at 980 ℃ and 250 MPa, the effects of HIP process on the microdefects and high temperature stress rupture life of the used superalloy with different initial microstructures were studied. The results indicated that the solid-solution treatment can significantly promote the diffusion of alloying elements, such as Re, W, Al, and Ta, reduce the area fraction of interdendritic eutectic, but significantly increase the average area fraction and size of micropores in the used alloy with as-cast state. While, HIP process can effectively reduce the average area fraction and size of microspores in the used alloy with as-cast state or as-solid-solution state, but cannot eliminate the interdendritic eutectic as remarkable as the solid-solution treatment. By HIP process of the used alloy with as-solid-solution state, the area fraction of micropores is reduced to 0.005%, the eutectic structure is basically eliminated, and the dendrite segregation of Re, W, Al, Ta and other elements is significantly alleviated, resulting in the higher stress ruputure life of the used alloy, about 40% over that of the used alloy with the standard heat treatment state. Performing HIP process on nickel-based single crystal superalloy alloy with as-solid-solution state is of benefit to the high temperature stress rupture life due to the reduction of microdefects and the homogenization of alloying elements, in comparison with performing HIP process directly on the alloy with as-cast sate.

Key words:  second-generation nickel-based single crystal superalloy      hot isostatic pressing      micropore      eutectic structure      stress rupture life     
Received:  15 January 2020     
ZTFLH:  TG132.32  
Fund: AECC Beijing Institute of Aeronautical Materials Cooperation Project(2017012311ZB)
Corresponding Authors:  LI Longfei     E-mail:  lilf@skl.ustb.edu.cn

Cite this article: 

HE Siliang, ZHAO Yunsong, LU Fan, ZHANG Jian, LI Longfei, FENG Qiang. Effects of Hot Isostatic Pressure on Microdefects and Stress Rupture Life of Second-Generation Nickel-Based Single Crystal Superalloy in As-Cast and As-Solid-Solution States. Acta Metall Sin, 2020, 56(9): 1195-1205.

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2020.00020     OR     https://www.ams.org.cn/EN/Y2020/V56/I9/1195

Fig.1  Schematic of the positions for micropore and microstructure observations in the used nickel-based single crystal (SX) superalloy
SpecimenStateHeat treatment process
ACAs-cast state-
ASAs-solid-solution stateAs-cast state+1290 ℃, 1 h+1300 ℃, 2 h+1315 ℃, 4 h, AC*
ACHAs-cast state+HIPAs-cast state+1300 ℃, 30 MPa, 2 h+1300 ℃, 100 MPa, 3 h
ASHAs-solid-solution state+HIPAs-solid-solution state+1300 ℃, 30 MPa, 2 h+1300 ℃, 100 MPa, 3 h
SHTSHTAs-solid-solution state+ageing treatment (1120 ℃, 4 h, AC*+870 ℃, 32 h, AC*)
ACHSAs-cast state+HIP+SHT*As-cast state+HIP+1315 ℃, 3 h, AC*+ageing treatment
ASHSAs-solid-solution state+HIP+SHT*As-solid-solution state+HIP+1315 ℃, 3 h, AC*+ageing treatment
Table 1  Heat treatment processes used in this work
Fig.2  Schematic of the heat treatment routes used in this work
Fig.3  Distributions (a1~d1) and morphological characteristics (a2~d2) of micropores in the used nickel-based SX superalloy before and after HIP treatment with the condition of 1300 ℃, 30 MPa, 2 h+1300 ℃, 100 MPa, 3 h, showing the effects of solid-solution treatment and HIP treatment on the micropores under different states
Fig.4  Average area fractions (a) and average diameters (b) of micropores in the used nickel-based SX superalloy before and after HIP treatment
Fig.5  The relative frequency distributions of micropore diameters in the used nickel-based SX superalloy before (a) and after (b) HIP treatment
Fig.6  The interdendritic eutectic microstructures in the used nickel-based SX superalloy before and after HIP treatment, showing that the eutectic microstructures were reduced obviously by solid-solution rather than by HIP treatments. Furthermore, the eutectic microstructure was completely eliminated in ASH specimen
Fig.7  Dendrite segregation coefficients (ki) of alloy elements in the used nickel-based SX superalloy before and after HIP treatment, showing that ki were reduced obviously by solid-solution and HIP treatments, especially for alloy elements Re, W, Al, Nb and Ta
SpecimenReWAlNbMoCrCoTaNi
AC2.231.660.860.430.941.081.140.640.97
AS1.661.280.940.970.981.021.030.860.96
ACH1.751.410.940.851.001.051.050.810.97
ASH1.371.170.970.940.910.991.000.950.99
Table 2  ki of alloy elements in the used nickel-based SX superalloy before and after HIP treatment
Fig.8  Typical microstructures of γ/γ' phases in the dendrite cores in the used nickel-based SX superalloy under different states
SpecimenVolume fraction of γ' / %Size of γ' / nm
SHT68.7±2.5410±110
ACHS66.1±2.3401±91
ASHS66.0±2.1407±123
Table 3  Volume fractions and sizes of γ' phases in the dendritic cores of the used nickel-based SX superalloy under different states
Fig.9  The high temperature stress rupture lives of the used nickel-based SX superalloy under different states at 980 ℃ and 250 MPa, showing that the stress rupture lives could be obviously increased by HIP treatment
Fig.10  Schematic of the changes of interdendritic eutectic structures and micropores of the used nickel-based SX superalloy under different states during HIP treatment (P—pressure from HIP)
Fig.11  Microstructures around cracks in the interdendritic area from the longitudinal section of the fractured stress-rupture sample in the used nickel-based SX superalloy
[1] Zhao X B, Liu L, Yang C B, et al. Advance in research of casting defects of directionally solidified nickel-based single superalloys [J]. J. Mater. Eng., 2012, (1): 93
(赵新宝, 刘 林, 杨初斌等. 镍基单晶高温合金凝固缺陷研究进展 [J]. 材料工程, 2012, (1): 93)
[2] Elliott A J, Pollock T M, Tin S, et al. Directional solidification of large superalloy castings with radiation and liquid-metal cooling: A comparative assessment [J]. Metall. Mater. Trans., 2004, 35A: 3221
[3] Zhang J, Lou L H. Directional solidification assisted by liquid metal cooling [J]. J. Mater. Sci. Technol., 2007, 23: 289
[4] Chen R Z. Development status of single crystal superalloys [J]. J. Mater. Eng., 1995, (8): 3
(陈荣章. 单晶高温合金发展现状 [J]. 材料工程, 1995, (8): 3)
[5] Ma W Y, Li S S, Qiao M, et al. Effect of heat treatment on microstructure and stress rupture life of Ni-base single crystal superalloy [J]. Chin. J. Nonferrous Met., 2006, 16: 937
doi: 10.1016/S1003-6326(06)60355-5
(马文有, 李树索, 乔 敏等. 热处理对镍基单晶高温合金微观组织和高温持久性能的影响 [J]. 中国有色金属学报, 2006, 16: 937)
[6] Danninger H, Weiss B. The influence of defects on high cycle fatigue of metallic materials [J]. J. Mater. Process. Technol., 2003, 143-144: 179
[7] Murakami Y, Endo M. Effects of defects, inclusions and inhomogeneities on fatigue strength [J]. Int. J. Fatigue, 1994, 16: 163
[8] Aldinger F. Materials by Powder Technology, PTM93 [M]. Obserusel, Germany: DGM Informationsgesellschaft, 1993: 247
[9] Guo H M, Zhao Y S, Zheng S, et al. Effect of hot-isostatic pressing on microstructure and mechanical properties of second generation single crystal superalloy DD6 [J]. J. Mater. Eng., 2016, 44(10): 60
(郭会明, 赵云松, 郑 帅等. 热等静压对第二代单晶高温合金DD6显微组织和力学性能的影响 [J]. 材料工程, 2016, 44(10): 60)
[10] Atkinson H V, Davies S. Fundamental aspects of hot isostatic pressing: An overview [J]. Metall. Mater. Trans., 2000, 31A: 2981
[11] Bocanegra-Bernal M H. Hot isostatic pressing (HIP) technology and its applications to metals and ceramics [J]. J. Mater. Sci., 2004, 39: 6399
[12] Ning Y Q, Yao Z K, Fu M W, et al. Recrystallization of the hot isostatic pressed nickel-base superalloy FGH4096: I. Microstructure and mechanism [J]. Mater. Sci. Eng., 2011, A528: 8065
[13] Galante R, Figueiredo-Pina C G, Serro A P. Additive manufacturing of ceramics for dental applications: A review [J]. Dent. Mater., 2019, 35: 825
pmid: 30948230
[14] Wei C N, Bor H Y, Chang L. Effect of hot isostatic pressing on microstructure and mechanical properties of CM-681LC nickel-base superalloy using microcast [J]. Mater. Trans., 2008, 49: 193
[15] Zhao X M, Lin X, Chen J, et al. The effect of hot isostatic pressing on crack healing, microstructure, mechanical properties of Rene88DT superalloy prepared by laser solid forming [J]. Mater. Sci. Eng., 2009, A504: 129
[16] Cao L M, Liu L J, Chen J Y, et al. Effect of hot isostatic pressing temperature on the microstructure of a third generation single crystal superalloy DD10 [J]. J. Mater. Eng., 2013, (6): 1
(曹腊梅, 刘丽君, 陈晶阳等. 热等静压温度对第三代单晶高温合金DD10组织的影响 [J]. 材料工程, 2013, (6): 1)
[17] Roncery L M, Lopez-Galilea I, Ruttert B, et al. Influence of temperature, pressure, and cooling rate during hot isostatic pressing on the microstructure of an SX Ni-base superalloy [J]. Mater. Des., 2016, 97: 544
[18] Luo Y S, Guo H M, Zhao Y S, et al. Effect of hot isostatic pressing on high-temperature high cycle fatigue properties of a second generation single crystal superalloy DD6 [J]. Mater. Mech. Eng., 2016, 40(7): 51
(骆宇时, 郭会明, 赵云松等. 热等静压对第二代DD6单晶高温合金高温高周疲劳性能的影响 [J]. 机械工程材料, 2016, 40(7): 51)
[19] Reed R C, Cox D C, Rae C M F. Damage accumulation during creep deformation of a single crystal superalloy at 1150 ℃ [J]. Mater. Sci. Eng., 2007, A448: 88
[20] Chang J C, Choi C, Kim J C, et al. Development of microstructure and mechanical properties of a Ni-base single-crystal superalloy by hot-isostatic pressing [J]. J. Mater. Eng. Perform., 2003, 12: 420
[21] Shi Q Y, Li X H, Zheng Y R, et al. Formation of solidification and homogenisation micropores in two single crystal superalloys produced by HRS and LMC processes [J]. Acta Metall. Sin., 2012, 48: 1237
doi: 10.3724/SP.J.1037.2012.00172
(石倩颖, 李相辉, 郑运荣等. HRS和LMC工艺制备的两种镍基单晶高温合金铸态及固溶微孔的形成 [J]. 金属学报, 2012, 48: 1237)
doi: 10.3724/SP.J.1037.2012.00172
[22] Bokstein B S, Epishin A I, Link T, et al. Model for the porosity growth in single-crystal nickel-base superalloys during homogenization [J]. Scr. Mater., 2007, 57: 801
[23] Li X W, Wang L, Dong J S, et al. Evolution of micro-pores in a single-crystal nickel-based superalloy during solution heat treatment [J]. Metall. Mater. Trans., 2017, 48A: 2682
[24] Toloraya V N, Svetlov I L. Effect of conditions of directed crystallization and heat treatment on the porosity of single crystals of high-temperature nickel alloys [J]. Russ. Metall., 1991, 5: 70
[25] Epishin A, Fedelich B, Link T, et al. Pore annihilation in a single-crystal nickel-base superalloy during hot isostatic pressing: Experiment and modelling [J]. Mater. Sci. Eng., 2013, A586: 342
[26] Yan B C, Zhang J, Lou L H. Effect of boron additions on the microstructure and transverse properties of a directionally solidified superalloy [J]. Mater. Sci. Eng., 2008, A474: 39
[27] Schmidt R, Feller-Kniepmeier M. Effect of heat treatments on phase chemistry of the nickel-base superalloy SRR 99 [J]. Metall. Trans., 1992, 23A: 745
[28] Wilson B C, Cutler E R, Fuchs G E. Effect of solidification parameters on the microstructures and properties of CMSX-10 [J]. Mater. Sci. Eng., 2008, A479: 356
[29] Yu Z, Rao S X, Zheng Z, et al. Interaction of hot isostatic pressing temperature and hydrostatic pressure on the healing of creep cavities in a nickel-based superalloy [J]. Mater. Des., 2013, 49: 25
doi: 10.1016/j.matdes.2013.01.055
[30] Zhou Y, Zhang Z, Zhong Q P, et al. Model for healing of creep cavities in nickel-based superalloys under hot isostatic pressing [J]. Comput. Mater. Sci., 2012, 65: 320
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[13] . [J]. 金属学报, 2007, 43(11): 1221-1227 .
[14] XU Daming;CAO Fuyang;LI Qingchun(Harbin Institute of Technology;Harbin 150001)(Manuscript received 1994-12-19;in revised form 1995-06-19). STRUCTURE CHANGES OF DIRECTIONALLY SOLIDIFIED EUTECTIC Pb-Sn ALLOY UNDER VARYING GROWTH VELOCITY[J]. 金属学报, 1995, 31(11): 494-500.
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