HIGH-TEMPERATURE TENSILE FRACTURE BEHAVIOR OF DIRECTIONALLY SOLIDIFIED Ni,Cr,Al-TaC EUTECTIC SUPERALLOY
The high-temperature tensile fracture behavior of the Ni, Cr, Al-TaC eutectic superalloy directionally solidified under high temperature gradient is investigated. The hightemperature tensile fracture of this in situ composite has ductile character with lots of ductile nests whose diameters decrease with the increasing solidification rates. The maximum σb and δ are respectively 668.5MPa and 19.6%. There is a TaC whisker in the center of each nest, and the deformation of γ' and TaC is uneven. The hightemperature tensile behavior cannot be explained by the rule of mixtures but is decided by the formation of the plastic deforrmation band. The crack extension model is given.
作 者： J.Zhang J.J.Yu H.Z.Fu 作者单位： J.Zhang,H.Z.Fu(State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072,China)J.J.Yu(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
刊 名： 金属学报(英文版) ISTIC EI 英文刊名： ACTA METALLURGICA SINICA(ENGLISH LETTERS) 年，卷(期)： 2004 17(4) 分类号： 关键词： Ni Cr Al-TaC eutectic superalloy directional solidification in situ composite high-temperature tenslie fracture