(1. 中國(guó)科學(xué)院 金屬研究所， 沈陽(yáng) 110016;
2. 湖南科技大學(xué) 機(jī)械設(shè)備健康維護(hù)省重點(diǎn)實(shí)驗(yàn)室， 湘潭 411201)
摘 要: 研究擠壓NiAl-25Cr合金在1 073~1 123 K溫度區(qū)間的蠕變行為。 結(jié)果表明： 在實(shí)驗(yàn)溫度區(qū)域內(nèi)， 擠壓NiAl-25Cr合金表現(xiàn)出兩種明顯不同的蠕變機(jī)制； 在低溫區(qū)域中， 由位錯(cuò)的滑移和攀移控制蠕變變形過(guò)程； 而在高溫區(qū)域中， 位錯(cuò)粘滯滑移控制蠕變變形過(guò)程。 在研究蠕變的溫度范圍內(nèi)， 合金的蠕變表觀激活能高于Ni的晶格自擴(kuò)散能， 這可以解釋為在蠕變瞬時(shí)變形過(guò)程中， 第二相粒子沿著基體相運(yùn)動(dòng)的結(jié)果， 第二相粒子可能是γ＇-Ni3Al相或α-Cr相。
關(guān)鍵字: NiAl; 金屬間化合物; 高溫蠕變
NiAl-25%Cr alloy
（1. Institute of Metal Research, Chinese Academy of Sciences,
Shenyang 110016, China;
2. Hunan Provincial Key Laboratory of Health Maintenance for Mechanical Equipment, Hunan University of Science and Technology,
Xiangtan 411201, China）
Abstract: The creep behavior and mechanisms of extruded NiAl-25Cr alloy at elevated temperatures were investigated. The results of the analysis of the creep data in the temperature range of 1 073-1 123 K reveals two distinct regions of creep behavior in this material. At lower temperature, the creep characteristics are consistent with a structure controlled creep process where some form of dislocation climb controls the creep deformation. At higher temperature, the creep characteristics are consistent with mobility-controlled deformation where viscous glide of dislocations controls the creep. The apparent activation energies determined for creep in both regions exceed by a considerable amount, the value for lattice self-diffusion in Ni. This can be explained in terms of the simultaneous deformation of second phase particles along with the Ni matrix during creep. The second phase most likely deforming along with the Ni matrix is the γ＇-Ni3Al and α-Cr phase.
Key words: NiAl-25Cr alloy; intermetallics; high-temperature creep
