Z.T.Yu1
,
2)
,
L.Zhou1)
,
2)
,
J.Deng2) and H.C.Gu1) 1) College of MaterialScience and Engineering
,
Xi’an Jiaotong University
,
Xi’an 710049
,
China 2) NorthwestInstitute for Nonferrous Metal Research
,
P. O.Box 51
,
Xi’an 710016
,
China
金属学报(英文版)
Thelow cyclefatigue( LCF) propertiesof Ti 2 Al 2 5 Zralloytubeand rod specimens weredetermined at R.T. Thestress～strain curve equation under cyclic and monotonicloading andtherelation of totalstrain vsfatiguelife of Ti 2 Al 2 5Zr alloy were established. Theeffectsofstrain ratio R,strain amplitudeεaandspecimenshapeoncyclicdeformingbehavior and fatigueproperties were analyzed . The fatiguefracture features were also discussed ac cording as SEMobservation. The resultsshow , at R = 0 1 ,thecyclicstress straincurvesof Ti 2 Al 2 5Zr alloytube and rodspecimensappear ascyclesoftening. When Ris 1 ,itsrodspecimen behavesascyclesoftening;atlow εavalues; whereasitbehavesascyclehardeningat high εa values. The LCFproperties determined withtubespecimen islower apparentlythanthat withrod one. Thereare muchirregularrecrystallineconvexin LCFfracturesof Ti 2 Al 2 5Zr alloytubeand rodspecimens, and muchsecondarycracks,fatiguestriationsand holes alsoexistamongthem .
关键词:
Ti 2 Al 2 5 Zralloy
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彭宁琦
,
唐广波
,
刘正东
,
吴秀月
金属学报
doi:10.3321/j.issn:0412-1961.2009.03.013
根据Aaronson提出的超组元模型,借助Ae3的实验数据,提出了修正的置换型元素Xi(Xi=Si,Mn,Ni,Co,Mo,Al,Cu,Cr)的Zener两参数,修正中考虑了合金元素间的交互作用.修正后的超组元模型的预测精度明显改善:Ae3计算值与实验值的标准差为10.8℃,与Thermo-Calc计算值的标准差为2.35℃;Ae1计算值与实验值的标准差为6.8℃.按照马氏体相变热力学的计算方法,采用经修正的参数计算了马氏体相变开始温度Ms,提高了Ms点的预测精度,计算值与实验值的标准差为25.3℃.
关键词:
相变
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热力学
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超组元模型
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相变平衡温度
盛广
,
杨志刚
金属学报
根据Fe--C--Xi合金系的正平衡和准平衡热力学模型，推导了简便的奥氏体--铁素体相变驱动力计算解析式。根据公式, 代入合金原始成分和Ae3温度, 即可准确计算正平衡和准平衡模式下的奥氏体--铁素体相变驱动力。采用这一方法计算了Fe--C--Mn--Si--Ni--Cr--Mo--Cu八元系的正平衡和准平衡奥氏体--铁素体相变驱动力。
关键词:
正平衡
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