1. Key Laboratory of Advanced High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China;
2. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China;
3. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China
Abstract：Effects of the hot-isostatic pressing (HIP) temperature (1280,1300,1320℃) on microstructures and mechanical properties of a second generation single crystal superalloy DD6 were investigated. The results show that the HIP treatment significantly decrease the cast porosity number of DD6 compared with standard treated specimens. Especially, the cast porosity volume fraction is deceased from 0.31% to 0.04% after the HIP treatment of 1300℃/100MPa, 4h. The cast eutectic volume fractions are remarkably reduced with increasing HIP temperature. The HIP treatments nearly unchanged the creep lives, While they greatly promote the low cycle fatigue lives. The elimination of cast microspores using the HIP treatment of 1300℃/100MPa, 4h result in the inhibition of crack initiation during fatigue and improve the low cycle fatigue lives one order of magnitude larger than that after standard heat treatment.
[1] REED R C. The Superalloys:Fundamentals and Applications[M]. Cambridge, UK:Cambridge University Press, 2006.
[2] 张剑, 赵云松, 骆宇时, 等. 一种镍基单晶高温合金的高温蠕变行为[J]. 航空材料学报, 2013, 33(3):1-5. ZHANG J, ZHAO Y S, LUO Y S, et al. Creep behavior of a nickel-based single crystal superalloy[J]. Journal of Aeronautical Materials, 2013, 33(3):1-5.
[3] FUCHS G E. Improvement of creep strength of a third generation, single-crystal Ni-base superalloy by solution heat treatment[J]. Journal of Materials Engineering & Performance, 2002, 11(1):19-25.
[4] LAMM M, SINGER R F. The effect of casting conditions on the high-cycle fatigue properties of the single-crystal nickel-base superalloy PWA 1483[J]. Metallurgical & Materials Transactions A, 2007, 38(6):1177-1183.
[5] BOKSTEIN B S, EPISHIN A I, LINK T, et al. Model for the porosity growth in single-crystal nickel-base superalloys during homogenization[J]. Scripta Materialia, 2007, 57(9):801-804.
[6] LECOMTE-BECKERS J. Study of microporosity formation in nickel-base superalloys[J]. Metallurgical & Materials Transactions:A, 1988, 19(9):2341-2348.
[7] KUNZ L, KUKA P, KONENA R, et al. Casting defects and high temperature fatigue life of IN 713LC superalloy[J]. International Journal of Fatigue, 2012, 41(8):47-51.
[8] FRITZEMEIER L G. The influence of high thermal gradient casting, hot isostatic pressing and alternate heat treatment on the structure and properties of a single crystal nickel base superalloy[A]. REICHMAN S, DUHL D N, MAURER G, et al. Superalloys 1988[C]. Champion,PA:TMS, 1988. 265-274.
[9] 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]. Journal of Materials Engineering & Performance, 2003, 12(4):420-425.
[10] 韩梅, 骆宇时. 热等静压对DD3单晶高温合金组织与性能的影响[J]. 材料工程, 2008, (8):40-43. HAN M, LUO Y S. Effect of HIP on microstructures and properties of DD3 single crystal superalloys[J]. Journal of Materials Engineering, 2008, (8):40-43.
[11] WASIELEWSKI G E, LINDBLAD N R. Elimination of casting defects using HIP[A]. JOHN K T, STANLEY T W, HUGH M I, et al. Superalloys 1972[C]. Warrendale, PA:TMS, 1972. D1-D24.
[12] KIM M T, CHANG S Y, WON J B. Effect of HIP process on the micro-structural evolution of a nickel-based superalloy[J]. Materials Science & Engineering A, 2006, 441(1):126-134.
[13] 李影, 苏彬. DD6单晶合金的高温低周疲劳机制[J]. 航空动力学报, 2003, 18(6):732-736. LI Y, SU B. Mechanisms of low cyclic fatigue of DD6 alloy at elevated temperature[J]. Journal of Aerospace Power, 2003, 18(6):732-736.
[14] 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(10):1237-1247. 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 Metallurgica Sinica, 2012, 48(10):1237-1247.
[15] REED R C, COX D C, RAE C M F. Damage accumulation during creep deformation of a single crystal superalloy at 1150℃[J]. Materials Science & Engineering A, 2007, 448:88-96.
2016, Vol. 44 
