Transverse stress rupture properties of a third generation single crystal superalloy at medium and elevated temperatures
YANG Wan-peng, LI Jia-rong, LIU Shi-zhong, ZHAO Jin-qian, SHI Zhen-xue, WANG Xiao-guang
Science and Technology on Advanced High Temperature Structural Materials Laboratory, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China
Abstract：At the conditions of 760℃/800 MPa, 980℃/250 MPa and 1100℃/137 MPa, the transv-erse stress rupture properties of a nickel-based third generation single crystal superalloy were investigated. The results show that the stress rupture life and elongation of the transverse specimens are lower than those of the longitudinal specimens at 760℃/800 MPa, 980℃/250 MPa and 1100℃/137 MPa. The dislocation configurations of the stress ruptured transverse and longitudinal specimens are the same. There are intersecting stacking faults in the γ' phases after stress ruptured at 760℃/800 MPa, and the dislocations are tangled and high densities of dislocation networks have formed at the γ/γ' interface after stress ruptured at 1100℃/137 MPa. The transverse and longitudinal specimens show quasi-cleavage and dimple mixture mode at 760℃/800 MPa, while they both show dimple mode at 980℃/250 MPa and 1100℃/137 MPa. The fracture mechanisms of transverse specimens of the first generation single crystal superalloy DD3, the second generation single crystal superalloy DD6 and the third generation single crystal superalloy in our study at medium and elevated temperatures are basically the same. The main reason for the transverse specimens have a lower stress rupture properties than the longitudinal specimens is that the external applied stress is perpendicular to the primary interdendritic interface formed during the directional solidification process.
杨万鹏, 李嘉荣, 刘世忠, 赵金乾, 史振学, 王效光. 一种第三代单晶高温合金中高温横向持久性能[J]. 材料工程, 2020, 48(7): 139-145.
YANG Wan-peng, LI Jia-rong, LIU Shi-zhong, ZHAO Jin-qian, SHI Zhen-xue, WANG Xiao-guang. Transverse stress rupture properties of a third generation single crystal superalloy at medium and elevated temperatures. Journal of Materials Engineering, 2020, 48(7): 139-145.
[1] GELL M, DUHL D N, GIAMEI A F. The development of single crystal superalloy turbine blades[J]. Superalloys,1980:205-214.
[2] LI J R, LIU S Z, WANG X G, et al. Development of a low-cost third generation single crystal superalloy DD9[J]. Superalloys, 2016:57-63.
[3] LIU L, HUANG T W, ZHANG J, et al. Microstructure and stress rupture properties of single crystal superalloy CMSX-2 under high thermal gradient directional solidification[J]. Materials Letters, 2007, 61(1):227-230.
[4] YU J, SUN X, ZHAO N, et al. Effect of heat treatment on microstructure and stress rupture life of DD32 single crystal Ni-base superalloy[J]. Materials Science and Engineering:A, 2007, 460/461:420-427.
[5] 喻健,李嘉荣,韩梅,等.近
[001] 取向DD6单晶高温合金980℃/250 MPa持久性能各向异性研究[J].材料工程,2012(4):1-5. YU J, LI J R, HAN M, et al. Anisotropy of stress rupture properties of DD6 single crystal superalloy at 980℃/250 MPa near
[001] orientation[J]. Journal of Materials Engineering, 2012(4):1-5.
[6] SHAH D M, CETEL A. Evaluation of PWA1483 for large single crystal IGT blade applications[J]. Superalloys,2000:295-304.
[7] 陈德厚,吴仲棠,钟振刚,等.DD3单晶高温合金的中温横向持久性能[J].航空材料学报,1985(3):1-5. CHEN D H, WU Z T, ZHONG Z G, et al. Transverse stress rupture properties of single crystal superalloy DD3 at medium temperature[J]. Journal of Aeronautical Materials,1985(3):1-5.
[8] 赵金乾,李嘉荣,刘世忠,等.单晶高温合金DD6的中温横向持久性能[J].材料工程,2009(3):1-5. ZHAO J Q, LI J R, LIU S Z, et al. Transverse stress-rupture properties of single crystal superalloy DD6 at mediate temperature[J]. Journal of Materials Engineering, 2009(3):1-5.
[9] SHI Z X, LI J R, LIU S Z, et al. Effects of dendritic orientation on stress rupture properties of DD6 single crystal superalloy[J]. Journal of Iron and Steel Research, International, 2011, 18(10):66-71.
[10] SHI Z X, LIU S Z, HAN M, et al. Stress rupture properties and fracture behavior of DD6 single crystal superalloy[J]. Materials Science Forum, 2016, 849:468-474.
[11] 刘昌奎,杨胜,何玉怀,等.单晶高温合金断裂特征[J].失效分析与预防,2010,5(4):225-230. LIU C K, YANG S, HE Y H, et al. Fracture features of single crystal superalloys[J]. Failure Analysis and Prevention, 2010, 5(4):225-230.
[12] MACLACHLAN D W, KNOWLES D M. Modelling and prediction of the stress rupture behaviour of single crystal superalloys[J]. Materials Science and Engineering:A, 2001, 302(2):275-285.
[13] HOPGOOD A A, MARTIN J W. The creep behaviour of a nickel-based single-crystal superalloy[J]. Materials Science and Engineering, 1986, 82(1/2):27-36.
[14] LEVERANT G R, DUHL D N. The effect of stress and temperature on the extent of primary creep in directionally solidified nickel-base superalloys[J]. Metallurgical Transactions, 1971, 2(3):907-908.
[15] HAN G M, YU J J, SUN Y L, et al. Anisotropic stress rupture properties of the nickel-base single crystal superalloy SRR99[J]. Materials Science and Engineering:A,2010,527(21):5383-5390.
[16] RAE C M F, REED R C. Primary creep in single crystal superalloys:origins, mechanisms and effects[J]. Acta Materialia, 2007, 55(3):1067-1081.
[17] SHI Z X, LI J R, LIU S Z, et al. Creep properties and microstructure evolution of nickel-based single crystal superalloy at different conditions[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(8):2536-2543.
[18] SASS V, FELLER-KNIEPMEIER M. Orientation dependence of dislocation structures and deformation mechanisms in creep deformed CMSX-4 single crystals[J]. Materials Science and Engineering:A, 1998, 245(1):19-28.
[19] 刘丽荣,金涛,赵乃仁,等.一种镍基单晶高温合金蠕变机制的研究[J].金属学报,2005,41(11):1215-1220. LIU L R, JIN T, ZHAO N R, et al. Creep deformation mechanism in a Ni base single crystal superalloy[J]. Acta Metallurgica Sinica, 2005, 41(11):1215-1220.
[20] YAN G W P, LI J R, LIU S Z, et al. Orientation dependence of transverse tensile properties of nickel-based third generation single crystal superalloy DD9 from 760 to 1100℃[J]. Transactions of Nonferrous Metals Society of China, 2019,29(3):558-568.
[21] CHENG K Y, JO C Y, KIM D H, et al. Influence of local chemical segregation on the γ' directional coarsening behavior in single crystal superalloy CMSX-4[J]. Materials Characterization, 2009, 60(3):210-218.
[22] 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):93-98. ZHAO X B, LIU L, YANG C B, et al. Advance in research of casting defects of directionally solidified nickel-based single superalloys[J]. Journal of Materials Engineering, 2012(1):93-98.
2020, Vol. 48 
