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DIRECTIONAL COARSENING OF THE γ''-PHASE DURING COMPRESSION CREEP OF A SINGLE CRVSTAL NICKEL-BASE SUPERALLOY
田素贵,周惠华,张静华,杨洪才,徐永波,胡壮麒
金属学报 , 1998,
Abstract: 对「001」取向单晶镍基合金恒温恒载压缩蠕变不同时间的组织形貌进行了SEM和TEM观察表明:蠕变初期,两立方γ‘相沿平行于应力轴方向扩散相连定向生长成为条形筏结构;垂直通道中基体「001」晶向共格应变量减小,应变能降低是合金元素定向扩散形成γ’相符结构的驱动力;压缩与拉伸蠕变相比较,γ’相形筏所需要的时间较长,应力较大。
A DIRECTIONAL COARSENING MECHANISM OF THE γ'-PHASE DURING CREEP OF A SINGLE CRYSTAL NICKEL-BASE SUPERALLOY
田素贵,周惠华,张静华,杨洪才,徐永波,胡壮麒
金属学报 , 1998,
Abstract: 对001]取向单晶镍基合金恒载拉伸蠕变不同阶段的组织形貌进行了SEM,TEM观察和EDAX成分分析,研究了γ'相定向粗化过程及机理结果表明:蠕变初期,两相邻γ'相呈侧平面对接方式,沿垂直于应力轴方向定向生长为类似筛网的核状组织,外加应力使γ'/γ界面共格应变减少,应变能降低,释放的能量是促使合金元素定向扩散形成筏状γ'结构的驱动力.
SOLIDIFICATION CHARACTERS OF SUPERFINE DIRECTIONAL COLUMNAR GRAINS IN CAST NICKEL-BASE SUPERALLOY
镍基高温合金超细定向柱晶的凝固特性

LIU Zhongyuan,YANG Aimin,LI Jianguo,SHI Zhengxing,FU Hengzhi,
刘忠元
,杨爱民,李建国,史正兴,傅恒志

材料研究学报 , 1992,
Abstract: This paper deals with solidification characters of superfine directional columnargrains in cast nickel-base superalloy K405 with rapid directional solidification equipment withsuper-high temperature gradient.Experimetal results show that superfine directi
OBSERVATION OF COMPETITIVE GROWTH IN A DIRECTIONALLY SOLIDIFIED NICKEL BASE SINGLE CRYSTAL SUPERALLOY
单晶高温合金定向凝固过程中晶体竞争生长观察

FU Hengzhi,HE Guo,LI Jianguo,
傅恒志
,何国,李建国

金属学报 , 1997,
Abstract: Experiments have been done on bi and tetra-crystal competitive growth in a nickel base single crystal superalloy to imitate the competitive growth during directional solidification. The grain orientations were controlled by seed crystals. Results show that the competitive growth is dependent on the relative orientations of grains and their relation with the direction of maximum temperature gradient. Grains with their preferred growth direction (<001> in nickel base superalloy) nearer to maximum temperature gradient will grow faster than those with their preferred growth direction far away from maximum temperature gradient in the condition of bi-crystal as well as tetra-crystal competitive growth. A third grain may appear and grow as a single crystal if two seed crystals with their preferred growth directions are far away from that of maximum temperature gradient in a divergent way in bicrystal competitive growth.
Antiphase Boundary Strengthening in a Single Crystal Nickel-base Superalloy
Antiphase Boundary Strengthening in a Single Crystal Nickel—base Superalloy

Jinghua ZHANG,Tao JIN,Yongbo XU,Zhuangqi HU,Xin WU,
Jinghua ZHANG
,Tao JIN,Yongbo XU and Zhuangqi HUShenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences,Shenyang,ChinaXin WU

材料科学技术学报 , 2002,
Abstract: An investigation has been made into strengthening mechanism in a single crystal nickel-base superalloy DD8 by transmission electron microscopy. The results show that the stress rupture strength of the alloy increases with a dominate role in strengthening of the single crystal Ni-base superalloy DD8.There are three kinds of mechanisms for forming the APBs which were observed in the present materials. One is matrix dislocation network. The contribution of the antiphase boundary energy to the strength of the alloy can be expressed by:Burgers vector; a is the lattice constant; G is the shear modulus, and k is the proportional constant.
SOLIDIFICATION OF NICKEL-BASED SINGLE CRYSTAL SUPERALLOY BY ELECTRIC FIELD
YS Yang,XH Feng,GF Cheng,YJ Li,ZQ Hu,
Y.S.
,Yang,X.H.,Feng,G.F.,Cheng,Y.J.,Li,Z.Q.,Hu

金属学报(英文版) , 2005,
Abstract: The crystal growth of a nickel-based single crystal superalloy DD3 was researched via controlled directional solidification under the action of a DC electric field. The cellular or dendrite spacing of the single crystal superalloy is refined and microsegregation of alloying elements Al, Ti, Mo and W, is reduced by the electric field. The electric field decreases the interface stability and reduces the critical growth rate of the ceUular-dendritic translation because of Thomson effect and Joule heating. The precipitation of the γ' phase is more uniform and the size of the γ' phase is smaller with the electric field than that without the electric field.
AN INVESTIGATION OF THE DIRECTIONAL SOLIDIFICATION OF A NICKEL-BASE SUPERALLOY

Lin Dongliang,Lin Tung-liang,Yao Deliang Shanghai Jiaotong University,

金属学报 , 1979,
Abstract:
MC CARBIDE FLOATATION IN A HOT CORROSION RESISTANT SINGLE CRYSTAL Ni-BASE SUPERALLOY DURING DIRECTIONAL SOLIDIFICATION
WANG Huaming TANG Yajun ZHANG Jinghua ZHANG Zhiya HU Zhuangqi Institute of Metal Research,Academia Sinica,Shenyang,China,
WANG Huaming TANG Yajun ZHANG Jinghua ZHANG Zhiya HU Zhuangqi Institute of Metal Research
,Academia Sinica,Shenyang,China

金属学报(英文版) , 1992,
Abstract: The floating phenomenon of MC carbide(TiC)in a hot corrosion resistant single crystal Ni-base superalloy was observed during planar and cellular interface directional solidification.The explanation about the phenomenon is presented.
Thermomechanical Fatigue Behaviour of a Nickel Base Superalloy
LIANG Jin R M Pelloux XIE Xishan Univiersity of Science,Technology Beijing,China MIT,Cambridge MA USA,
梁晋
,R.M.Pelloux,谢锡善

材料科学技术学报 , 1989,
Abstract: The isothermal low cycle fatigue (LCF)and thermomechanical fatigue (TMF) behaviourof a Ni-base superalloy was investigated. Theresults show that temperature plays an importantrole in both LCF and TMF. The alloy shows thelowest LCF fatigue resistance in the intermediatetemperature range (~760℃). For strain-controlledTMF, in-phase (IP) cycling is more damagingthan out-phase (OP) cycling. The high tempera-ture exposure in the TMF cycling influencesthe deformation behaviour at the low temperature.LCF lives at different temperatures, and IPand OP TMF lives are successfully correlatedby using the hysteresis parameter Δσ·Δε_p.
Property Enrichment of Aged Nickel Base Superalloy Supercast 247A
Lavakumar Avala,Ch.V.S. Murthy 2,Prince Kr singh 3,Bhargav Chaitanya 4
International Journal on Theoretical and Applied Research in Mechanical Engineering , 2013,
Abstract: The commercial nickel-base superalloy Supercast 247A can be used for applications in which is required high mechanical strength and corrosion resistance at elevated temperatures, such as turbine blades and automotive turbocharger rotors. The mechanical properties are totally connected to the morphology, size and distribution of γ' phase and carbides. In order to improve the mechanical properties, the material is subjected to solution and aging heat treatment, to raise the volume fraction of γ' phase in the matrix and to form carbides at grain boundaries. In the present study the Supercast 247A superalloy was remelted and cast to obtain the desired polycrystalline test bars by controlling casting parameters, followed by the investigation of precipitation morphology and mechanical properties with respect to solution treatment and aging treatment. The experimental results show that by well controlled casting parameters the Supercast 247A owns excellent castability to form a superalloy with fine grain structure, resistance to indentation as well as superior strength.
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