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In 718合金中δ-Ni_3Nb相的孪晶结构
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作者 孟庆昌 洪班德 伊晓 《金属学报》 SCIE EI CAS CSCD 北大核心 1991年第2期A157-A160,共4页
本工作发现在In 718合金δ-Ni_3Nb相中存在孪晶结构。通过衍射、衍衬综合分析及迹线分析,确定δ相孪晶面为{201}和{203}。δ相孪晶界两侧的点阵完全重合,但孪晶区内Nb原子的位置发生了有规律的变动。本文还给出了上述孪晶的变换矩阵。
关键词 δ-ni3nb 孪晶结构 IN718合金
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δ-Ni_3Nb对Inconel718合金低周疲劳断裂行为的影响 被引量:6
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作者 洪班德 伊晓 孟庆昌 《金属学报》 SCIE EI CAS CSCD 北大核心 1991年第1期A055-A060,共6页
本文研究了δ-Ni_3Nb相的尺寸及分布对Inconel718合金在650℃,恒应变控制循环应变作用下断裂行为的影响。结果表明,由高温固溶及中间时效造成的δ相沿晶界的锯齿状分布,可以提高材料对裂纹沿晶扩展的抗力,使低周疲劳断口由标准工艺处理... 本文研究了δ-Ni_3Nb相的尺寸及分布对Inconel718合金在650℃,恒应变控制循环应变作用下断裂行为的影响。结果表明,由高温固溶及中间时效造成的δ相沿晶界的锯齿状分布,可以提高材料对裂纹沿晶扩展的抗力,使低周疲劳断口由标准工艺处理后的沿晶型转变为穿晶。但是,与形成锯齿晶界的工艺相伴随的,δ相在晶内沿孪晶界面及贯穿晶粒的粗大片状析出,降低材料对循环应变的适应能力,常常过早地在δ相与基体界面处形成微孔甚至界面分离,使材料疲劳寿命降低。 展开更多
关键词 高温合金 疲劳 断裂 δ-ni3nb
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Phase Equilibria in Nb-Si-Mo Ternary Alloys at 1273 K and 2073 K 被引量:3
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作者 Huang Qiang Ma Chaoli Zhao Xinqing Xu Huibin 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第5期448-454,共7页
Phase equilibrium in Nb-Si-Mo ternary alloys (〈37.5 at.% Si) at 1 273 K and 2 073 K is investigated by using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive spectrosco... Phase equilibrium in Nb-Si-Mo ternary alloys (〈37.5 at.% Si) at 1 273 K and 2 073 K is investigated by using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The partial isothermal section at 1 273 K, which contains four single-phase regions, five two-phase regions and two three-phase regions, is basically the same as that at 1 973 K. However, when the temperature increases to 2 073 K, the three-phase region of Nbss+ct-(Nb(Mo))sSi3+13-(Nb,Mo)sSi3 obviously moves towards the Nb-rich comer. This suggests that Nb-Si-Mo ternary alloys remain stable at least up to 1 973 K. 展开更多
关键词 nb/nbsSi3 in-situ composite isothermal section phase equilibria MICROSTRUCTURE
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Bonding of Al_2O_3 ceramic and Nb using transient liquid phase brazing 被引量:1
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作者 于治水 梁超 +2 位作者 李瑞峰 吴铭方 祁凯 《中国有色金属学会会刊:英文版》 CSCD 2004年第1期99-104,共6页
The brazing of Al 2O 3 to Nb was achieved by the method of transient liquid phase (TLP) bonding. Ti foil and Ni 5V alloy foil were used as interlayers for the bonding. The base materials were brazed at 1 4231 573 K fo... The brazing of Al 2O 3 to Nb was achieved by the method of transient liquid phase (TLP) bonding. Ti foil and Ni 5V alloy foil were used as interlayers for the bonding. The base materials were brazed at 1 4231 573 K for 1120 min. The results show that the shear strength of the joint first increases and then decreases with increasing holding time and brazing temperature. The joint interface microstructure and elements distribution were investigated. It can be concluded that a composite structure, in which the base metals are solid solution Nb(V) and Nb(Ti) reinforced by Ni 2Ti, is formed when the brazing temperature is 1 473 K and holding time 15 min, and a satisfactory joint strength can be achieved. The interaction of Ti foil and Ni 5V foil leads to the formation of liquid eutectic phase with low melting point, at the same time the combination of Ti come from the interlayer with O atoms from Al 2O 3 results in the bonding of Al 2O 3 and Nb. 展开更多
关键词 氧化铝陶瓷 陶瓷/金属连接 钎焊 瞬间液相连接 TLP
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Microstructure and Stability of Fe_(73.5) Cu_1Nb_3Si_(13.5)B_9 Alloy at Different Stages of Phase Transformation
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作者 Guiyi ZENG, Qixian BA and Hualin ZENG (Northeastern University, Shenyang 110006, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第2期153-154,共2页
The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy an... The microstructure and the stability of Fe_73.5Cu_1Nb_3Si_13.5B_9 alloy at different stages of phase transformation were investigated through the observation of X-ray difraction and transmission electron microscopy and the measurement of magnetic aftereffect (MAE). It was found that the dependence of the volume fraction of amorphous phase and the MAE in the samples annealed from 450 to 700℃ on the annealing temperature is similar. 展开更多
关键词 B9 Alloy at Different Stages of phase Transformation Microstructure and Stability of Fe Cu1nb3Si SI
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Ag-loaded mesoporous Pb_3Nb_2O_8 photocatalysts with enhanced activity under visible-light irradiation 被引量:1
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作者 Xiaopeng Han Jianan Lü +5 位作者 Li Tian Lingru Kong Xuemei Lu Yong Mei Jiwei Wang Xiaoxing Fan 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2017年第1期83-91,共9页
Mesoporous Pb3Nb2O8 photocatalysts were synthesized by the evaporation‐induced self‐assembly (EISA) method. Ag was deposited on the surface of mesoporous Pb3Nb2O8 by a facile photoreduction process. The as‐prepared... Mesoporous Pb3Nb2O8 photocatalysts were synthesized by the evaporation‐induced self‐assembly (EISA) method. Ag was deposited on the surface of mesoporous Pb3Nb2O8 by a facile photoreduction process. The as‐prepared samples were characterized by TG‐DSC, XRD, N2 adsorption, HR‐TEM andUV‐Vis spectroscopy. The results revealed that mesoporous Pb3Nb2O8 has a large specific surfacearea and uniform pore size distribution both before and after Ag deposition. The photodegradationof 2‐propanol and acetaldehyde gas under visible‐light (λ > 420 nm) irradiation was employed toevaluate the photocatalytic activities of the samples. The results showed that the photocatalyticactivity of mesoporous Pb3Nb2O8 is greatly improved by the Ag co‐catalyst. These mesoporousPb3Nb2O8 exhibit photocatalytic activities as much as 41 times higher when compared with thePb3Nb2O8 prepared by the solid state reaction method. The content of loaded Ag ranged from 0.5%to 5% (Ag2SO4). The optimal loading was determined to be 1% corresponding the highest photocatalyti cactivity. These results clearly indicate that the activity of Pb3Nb2O8 can be improved to obtain an outstanding performance for the photodegradation of organic pollutants. 展开更多
关键词 MESOPORE MESOPORE Pb3nb2O8 PHOTOCATALYSIS Ag loading Gas‐phase degradation
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Poling Effects of Dielectric and Optical Properties on Pb(Zn1/3Nb2/3)1-xTixO3 Crystal
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作者 Tu Chi Shun Wang Fu Tang Chien R R Hugo Schmidt V Chew L L 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z1期166-168,共3页
Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were meas... Dipolar relaxation and dielectric/piezoelectric resonance in a (001)-cut Pb(Zn1/3Nb2/3)0.9Ti0.1O3 (PZNT10%) single crystal before and after electric (E)-field poling were presented. Dielectric permittivities were measured as functions of temperature, frequency and poling E-field strength. Frequency-dependent dielectric spectroscopy in the poled sample exhibits multiple piezoelectric resonances between 0.1 and 1 MHz, which can be described by the forced-damped-oscillator model. The resonant spectra show significant changes while phase transitions are taking place. The unpoled crystal shows almost no optical birefringence, indicating that the average structure symmetry is isotropic. Birefringence of the crystal is significantly enhanced by a prior E-field poling. 展开更多
关键词 Pb(Zn1/3nb2/3)1-xTixO3 DIELECTRIC PERMITTIVITY phase TRANSITIONS refractive indices
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Antisite defect types and temporal evolution characteristics of D0_(22)-Ni_3V structure:Studied by the microscopic phase field
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作者 ZHANG Jing,CHEN Zheng,ZHANG MingYi,LAI QingBo,LU YanLi & WANG YongXin School of Material Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2009年第8期1154-1160,共7页
Microscopic phase field simulation is performed to study antisite defect type and temporal evolution characteristic of D022-Ni3V structure in Ni75AlxV25-x ternary system.The result demonstrates that two types of antis... Microscopic phase field simulation is performed to study antisite defect type and temporal evolution characteristic of D022-Ni3V structure in Ni75AlxV25-x ternary system.The result demonstrates that two types of antisite defect VNi and NiV coexist in D022 structure;however,the amount of NiV is far greater than VNi;when precipitates transform from D022 singe phase to two phases mixture of D022 and L12 with enhanced Al:V ratio,the amount of VNi has no evident response to the secondary L12 phase,while NiV exhibits a definitely contrary variation tendency:NiV rises without L12 structure precipitating from matrix but declines with it;temporal evolution characteristic and temperature dependent antisite defect VNi,NiV are also studied in this paper:The concentrations of the both defects decline from high antistructure state to equilibrium level with elapsed time but rise with elevated temperature;the ternary alloying element aluminium atom occupies both α and β sublattices of D022 structure with a strong site preference of substituting α site. 展开更多
关键词 antisite DEFECT D022-ni3V MICROSCOPIC phase field
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固溶处理时Inconel 718焊接试样中铌的扩散 被引量:3
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作者 盛钟琦 李卫军 +1 位作者 王丛林 邱绍宇 《核动力工程》 EI CAS CSCD 北大核心 2003年第3期241-244,共4页
根据非稳态扩散方程,对Inconel 718焊接试样中铌在固溶处理时的均匀化过程进行了计算,以此说明了要求高温长时间固溶处理的原因,表明了减少条状组织中d-Ni3Nb相的间距是进一步提高延伸率的有效方法。
关键词 INCONEL718 固溶处理 扩散 β-ni3nb 延伸率
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铌欠缺对PZN基陶瓷微观结构和介电性能的影响 被引量:1
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作者 屈绍波 王书文 +1 位作者 郝涛 薛锦 《机械科学与技术》 CSCD 北大核心 2004年第7期860-862,共3页
使用化学混合法制备了PZN基陶瓷 ,研究了铌离子欠缺对其相组成、微观结构和介电性能的影响。随着铌离子欠缺量的增加 ,预烧粉体中的焦绿石相含量大幅度增加 ;但是微量铌离子欠缺对烧结后陶瓷的相组成没有什么影响 ,甚至当铌欠缺量达到 ... 使用化学混合法制备了PZN基陶瓷 ,研究了铌离子欠缺对其相组成、微观结构和介电性能的影响。随着铌离子欠缺量的增加 ,预烧粉体中的焦绿石相含量大幅度增加 ;但是微量铌离子欠缺对烧结后陶瓷的相组成没有什么影响 ,甚至当铌欠缺量达到 2 %时 ,陶瓷仍然为 10 0 %的钙钛矿结构。随着铌欠缺的增加 ,晶粒尺寸增大 ,但是陶瓷仍具有良好的成瓷性。铌欠缺使介电常数减小 ,但是对介电损耗影响很小 ;介电常数减小的原因归结为“有效有序微区” 展开更多
关键词 PB(ZN1/3nb2/3)O3 铌欠缺 相组成 微观结构 介电性能
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不同制备方法对PMN-PT陶瓷相结构与显微结构及介电性能的影响 被引量:2
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作者 张金选 杨祖培 《电子显微学报》 CAS CSCD 北大核心 2001年第2期136-139,共4页
本文采用熔盐法、传统氧化物混合法和二次合成法制备了 0 8PMN 0 2PT陶瓷 ,研究了它们对其相结构、显微结构和介电性能的影响。结果表明 :熔盐法制备的陶瓷不仅能获得纯钙钛矿相结构 。
关键词 熔盐法 相结构 介电性能 PMN-PT陶瓷 显微结构
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镧掺杂对PMN-PT陶瓷结构与性能的影响 被引量:2
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作者 张金选 《陕西师范大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第2期63-66,共4页
采用熔盐法制备了 0 .82PMN 0 .1 8PT xLa陶瓷 ,研究了掺镧离子对 0 .82PMN 0 .1 8PT陶瓷相结构、显微结构以及介电性能的影响 .结果表明 ,随着掺镧含量的增加 ,不仅预烧粉体和陶瓷的焦绿石相含量逐渐增加 ,而且在显微结构中逐渐出现了... 采用熔盐法制备了 0 .82PMN 0 .1 8PT xLa陶瓷 ,研究了掺镧离子对 0 .82PMN 0 .1 8PT陶瓷相结构、显微结构以及介电性能的影响 .结果表明 ,随着掺镧含量的增加 ,不仅预烧粉体和陶瓷的焦绿石相含量逐渐增加 ,而且在显微结构中逐渐出现了小颗粒 ,气孔增多 ,陶瓷的致密性逐渐下降 ,严重恶化了介电性能 ,导致介电常数急剧下降 ,但介电温度稳定性却大幅度提高 . 展开更多
关键词 镧掺杂 相结构 显微结构 介电性能 弛豫铂电陶瓷 PMN-PT陶瓷
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Microscopic phase field study of the antisite defect of Ni_3 Al in binary Ni-Al alloys 被引量:3
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作者 ZHANG Jing ,CHEN Zheng,LU YanLi,ZHANG MingYi & WANG YongXin State Key Laboratory of Solidification Processing School of Material Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2010年第11期2047-2053,共7页
The temporal evolution feature of a microscopic phase field model is utilized to study the antisite defects of L1 2-Ni 3 Al;this is quite different from other physicist’ interests.There are mainly two points in brief... The temporal evolution feature of a microscopic phase field model is utilized to study the antisite defects of L1 2-Ni 3 Al;this is quite different from other physicist’ interests.There are mainly two points in brief.Firstly,antisite defects Ni Al and Al Ni ,which are caused by the deviation from the stoichiometric Ni 3 Al,coexist in the Ni 3 Al phase.The surplus Ni atom in the Ni-rich side is prone to substitute Al thus producing the antisite defect Ni Al that maintains the stability of the L1 2 structure.In other case,the surplus Al atom in the Al-rich side is accommodated by a Ni sublattice consequently giving rise to antisite defect Al Ni .The calculated equilibrium occupancy probability of Ni Al is much higher than that of Al Ni .This point is generally in line with other theoretical and experimental works.Additionally,both Ni Al and Al Ni have a strong negative correlation to time step during the disorder-order transformation.Since the initial value of Ni Al and Al Ni on each site of the matrix is right at the concentration that we set,we can observe the decrease process of Ni Al and Al Ni from the initial disordered high anti-structure state to their respective equilibrium state,i.e.to the result of the ordering process further coarsening. 展开更多
关键词 antisite DEFECT L1 2 -ni 3 AL temporal evolution MICROSCOPIC phase field model
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Representation of A15 composition and T_C in internal-Sn Nb_3Sn superconducting strands 被引量:1
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作者 Andre SULPICE Jean-Louis SOUBEYROUX +1 位作者 Christophe VERWAERDE Gia Ky HOANG 《Science China(Technological Sciences)》 SCIE EI CAS 2010年第11期3020-3026,共7页
Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite confi... Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite configurations and some third element alloying were arranged. All the strand samples underwent a 210°C/50 h + 340°C/25 h thermal duration for Cu-Sn alloying. After that A15 phase formation heat treatment (HT) was applied for which the ME samples were chosen at three reaction temperatures of 675°C, 700°C and 725°C for 100 h and 200 h while the MF samples at four temperatures of 650°C, 675°C, 700°C and 725°C for 128 h and 200 h. The heat-treated samples were examined for A15 phase composition distribution by X-ray EDS. SQUID magnetization measurement was used to determine critical temperature TC. The obtained results demonstrate that for fully-reacted internal-Sn Nb3Sn superconductors the A15 phase composition and the intrinsic property TC are determined by the diffusion and solid state reaction mechanism and are independent of the factors including HT temperature, strand composite component and configuration arrangement, and the third element addition within the experimental range. 展开更多
关键词 internal-Sn nb3SN STRANDS A15 phase COMPOSITION phase formation heat treatment composite configuration and design third element ALLOYING
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Nb掺杂对Ni基合金中γ'→γ"相转变影响的第一原理研究 被引量:4
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作者 孙昊昉 田素贵 金莹 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2017年第2期449-455,共7页
通过第一原理计算Nb掺杂对γ'-Ni_3Al和γ"-Ni_3Nb两相形成热、结合能及态密度的影响,研究了Nb掺杂量γ'-Ni_3Al和γ"-Ni_3Nb两相的合金化行为。结果表明,在γ'-Ni_3Al和γ"-Ni_3Nb两相共存的熔体中,在Nb掺... 通过第一原理计算Nb掺杂对γ'-Ni_3Al和γ"-Ni_3Nb两相形成热、结合能及态密度的影响,研究了Nb掺杂量γ'-Ni_3Al和γ"-Ni_3Nb两相的合金化行为。结果表明,在γ'-Ni_3Al和γ"-Ni_3Nb两相共存的熔体中,在Nb掺杂量小于15.625at%范围内,与γ"-Ni_3Nb相比,γ'-Ni_3Al相有较好的稳定性;而Nb掺杂量大于18.75 at%时,γ"-Ni_3Nb相有更大的稳定性。其中在Nb掺杂15.452at%~16.34at%范围内,γ'-Ni_3Al和γ"-Ni_3Nb两相有相近的晶格常数,是使其发生γ'-Ni_3Al→γ"-Ni_3Nb共格相转变的必要条件。Nb掺杂量大于18.75at%后,γ'-Ni_3Al和γ"-Ni_3Nb两相费米能级处态密度的差值明显增大,γ"-Ni_3Nb相稳定性增强。此外,在γ"-Ni_3Nb相长大的同时,可发生γ'-Ni_3Al相的分解而消失。 展开更多
关键词 第一原理计算 γ'-ni3Al和γ"-ni3nb nb掺杂 态密度 相转变
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Element Segregation and Solidification Behavior of a Nb, Ti, Al Co-Strengthened Superalloy ЭК151 被引量:12
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作者 Yuan-Guo Tan Fang Liu +4 位作者 An-Wen Zhang Da-Wei Han Xiao-Yu Yao Wei-Wei Zhang Wen-Ru Sun 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2019年第10期1298-1308,共11页
The as-cast microstructure, element segregation and solidification behavior of a multi-alloyed superalloy ЭК151 have been investigated. The results show that the severe element segregation leads to the complicated p... The as-cast microstructure, element segregation and solidification behavior of a multi-alloyed superalloy ЭК151 have been investigated. The results show that the severe element segregation leads to the complicated precipitations at the inter-dendritic region, including η-Ni3(Ti, Nb), eutectic(γ + γ’) and Laves, which shows the characteristics of both Ti, Al-strengthened and Nb-strengthened alloys. Differential thermal analysis, heating and quenching tests reveal the solidification sequence as follows: Liquids →γ matrix →(Nb, Ti)C →η-Ni 3(Ti, Nb) →eutectic( γ+γ’) → Laves. The melting points are between 1250 and 1260 °C for(Nb, Ti)C, between 1200 and 1210 °C for η phase, between 1180 and 1190 °C for eutectic(γ+γ’) and Laves. γ’ initially precipitates from matrix at 1150 °C and achieves the maximum precipitation at 1130 °C. According to the microstructure evolution captured during solidification and composition analysis by an energy dispersive spectrometer and electron probe microanalyzer,(Nb, Ti)/Al ratio is put forward to explain the formation of η-Ni3(Ti, Nb) and eutectic( γ+γ’). The solidification of γ matrix increased the Nb, Ti concentration in the residual liquids, so the high(Nb, Ti)/Al ratio would result in the formation of η-Ni3(Ti, Nb); the precipitation of the phase consumed Nb and Ti and decreased the(Nb, Ti)/Al ratio in the liquid, which led to the precipitation of eutectic(γ + γ’). Laves formed by the sides of η-Ni3(Ti, Nb) and in front of the eutectic( γ + γ’) after Al, Ti were further depleted by the two phases and Cr, Co, Mo were rejected to liquids. 展开更多
关键词 SUPERALLOY ЭК151 Solidification Eutectic(γ+γ’) η-ni3(Ti nb) Laves
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ATI 718Plus合金国内研究进展 被引量:13
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作者 王民庆 邓群 +2 位作者 杜金辉 田志凌 朱静 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2016年第12期3335-3340,共6页
ATI 718Plus(简称718Plus)合金作为一种新型镍基变形高温合金涡轮盘材料,由于在700℃以下具备优异的综合力学性能、良好的热加工和焊接等工艺性能以及适宜的成本,而受到国内外的广泛关注。本文综述了近几年国内718Plus合金的研究进展,... ATI 718Plus(简称718Plus)合金作为一种新型镍基变形高温合金涡轮盘材料,由于在700℃以下具备优异的综合力学性能、良好的热加工和焊接等工艺性能以及适宜的成本,而受到国内外的广泛关注。本文综述了近几年国内718Plus合金的研究进展,主要包括:(1)718Plus合金相组成及合金特点;(2)P对718Plus合金组织及性能的影响规律及机理;(3)Al对718Plus合金组织及性能的影响规律及机理;(4)析出相对718Plus合金性能的影响规律及机理。 展开更多
关键词 718Plus合金 η-ni3Al0.5nb0.5相 三维原子探针(3DAP)
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K4169合金循环加载过程中的微观组织演变 被引量:2
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作者 吴贇 刘雅辉 +3 位作者 康茂东 高海燕 王俊 孙宝德 《金属学报》 SCIE EI CAS CSCD 北大核心 2020年第9期1185-1194,共10页
通过熔模精密铸造、循环加载和微观组织表征等方法研究了K4169合金循环加载过程中的微观组织演变特征,重点分析了不同循环周次后Laves相和δ-Ni3Nb相的变形和断裂特征。结果表明,在室温380 MPa应力幅值循环加载实验中,循环寿命主要取决... 通过熔模精密铸造、循环加载和微观组织表征等方法研究了K4169合金循环加载过程中的微观组织演变特征,重点分析了不同循环周次后Laves相和δ-Ni3Nb相的变形和断裂特征。结果表明,在室温380 MPa应力幅值循环加载实验中,循环寿命主要取决于显微疏松体积分数,裂纹优先萌生于试样表面的显微疏松位置。Laves相的断裂不受循环周次的影响,在循环加载初期,显微疏松附近的长带状Laves脆性相容易开裂,其内部还产生平行排列的二次裂纹,成为裂纹扩展的敏感区域。δ-Ni3Nb层片呈现2种变形和断裂特征:沿长度方向的开裂;层片表面滑移和断裂。循环加载初期,显微疏松附近的δ-Ni3Nb层片容易产生沿长度方向的开裂,而随着循环周次的增加,远离显微疏松的δ-Ni3Nb层片表面滑移迹线逐渐增多直至滑移断裂。γ-Ni基体在循环加载过程中产生孪生变形特征,导致应变局部化程度加剧,进而使Laves相和δ-Ni3Nb层片周围产生应力集中。 展开更多
关键词 K4169高温合金 循环应力 微观组织演变 LAVES相 δ-ni3nb
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GH4169G合金锻件条带缺陷微观检测及改进 被引量:2
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作者 孙凯 蔺虹宾 +1 位作者 何跃斌 苗景国 《特种铸造及有色合金》 CAS 北大核心 2020年第6期694-696,共3页
GH4169G合金锻件在低倍组织检验时出现明暗相间的条带缺陷,对其进行微观检验。结果表明,条带暗处的δ-Ni3Nb相较正常部位明显富集,晶粒度偏大,条带组织的出现与碳化物、碳氮化物的偏聚无关。借助JMatPro对GH4169G合金凝固过程的相转变... GH4169G合金锻件在低倍组织检验时出现明暗相间的条带缺陷,对其进行微观检验。结果表明,条带暗处的δ-Ni3Nb相较正常部位明显富集,晶粒度偏大,条带组织的出现与碳化物、碳氮化物的偏聚无关。借助JMatPro对GH4169G合金凝固过程的相转变规律进行模拟计算,发现合金中Nb元素的平衡分配系数最小,为0.19,容易形成成分偏析,这是形成明暗条带缺陷的主要原因。将合金锭均匀化热处理由原来2段改为3段后,即1120℃×15h+1160℃×30h+1190℃×60h,合金条带缺陷消失。 展开更多
关键词 GH4169G合金 条带缺陷 δ-ni3nb nb偏析
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