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Isothermal Oxidation Behavior of Dysprosium/S-Doped β-NiAl Alloys at 1200°C

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Journal of Materials Science & Technology 2014年第3期30卷 229-233页

作者： Lu Wang Dongqing Li Jian Chang Hongbo Guo Shengkai Gong Huibin Xu School of Materials Science and engineering Beihang University AVIC shenyang liming aero-engine group corporation Ltd.

A β--NiAI alloy with normal purity, a S-doped and a Dy and S co-doped （Y-NiAI alloys were prepared by arc-melting and their corresponding S contents were less than 20 ×10-6, 33 ×10-6 and 22 × 10-6, respectively. The isothermal oxidation behavior of the alloys at 1200 ℃ was investigated and the extent of S segregation at the scale-alloy interface was determined by scanning Auger microscopy. S-doping had no significant effect on the phase transformation rate from e- to β-Al2O3, while the addition of Dy retarded this process. For the S- doped alloy, scale rumpling occurred only after 2 h thermal exposure and numerous large voids were observed at the scale-alloy interface where S segregated. In contrast to this, the oxide scale formed on the Dy and S co-doped alloy still remained flat even after 50 h isothermal oxidation and only small voids existed at the interface where S segregation was not detected.

关键词： NiAl Dy S Isothermal oxidation Phase transformation Segregation

Effect of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece

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中国有色金属学会会刊：英文版 2007年第5期17卷 957-962页

作者：王明伟张立文裴继斌李辰辉张凡云 State Key Laboratory for Materials Modification by Laser Ion and Electron Beams Dalian University of Technology shenyang liming aero-engine group corporation

Temperature is one of the key parameters for BT20 titanium alloy cylindrical workpiece manufactured by vacuum hot bulge forming. A two-dimensional nonlinear thermo-mechanical coupled FE model was established. Numerical simulation of vacuum hot bulge forming process of titanium alloy cylindrical workpiece was carried out using FE analysis software MSC Marc. The effects of temperature on vacuum hot bulge forming of BT20 titanium alloy cylindrical workpiece were analyzed by numerical simulation. The simulated results show that the Y-direction displacement and the equivalent plastic strain of the workpiece increase with increasing bulge temperature. The residual stress decreases with increasing bulge temperature. The optimal temperature range of BT20 titanium alloy during vacuum hot bulge forming is 750-850 ℃. The corresponding experiments were carried out. The simulated results agreed well with the experimental results.

关键词：钛合金真空热膨胀温度作用数字模拟

Influence of Pre-Compressive Creep on Internal Friction Stress and Creep Parameters of Nickel-Base Single Crystal Superalloys

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稀有金属材料与工程 2009年第A03期38卷 28-32页

作者： Yu Xingfu Tian Sugui Zhao Zhonggang Du Hongqiang Shang Lijuan Cui Shusen shenyang University of Technology Shenyang 110023 China shenyang liming aero-engine corporation AVICI Shenyang 110043 China

By means of pre-compressive creep treatment, the cubic γ′ phase in a nickel base single crystal superalloy is transformed into the P-type rafted structure. And the influence of the pre-compressive creep on the internal friction stress and creep lifetimes of the superalloy are investigated by means of the measurement of the creep curves and microstructure observation. Results show that, compared to the P-type structure alloy, the full heat treated state alloy displays a bigger internal friction stress value of dislocation motion during steady state creep and a longer creep lifetimes. The creep activation energies of the full heat treated and P-type structures alloys are measured to be 462 kJ/mol and 412 kJ/mol, respectively. Thereinto, the P-type rafted γ′ phase in the alloy is transformed into the N-type structure during tensile creep. And the N-type γ′ phase transformed from the P-type structure displays a shorter size in length, this is a main reason of the P-type structure alloy possessing a shorter creep lifetimes due to creep dislocation moving easily over the rafted γ′ phase.

关键词：镍基单晶合金物理性能结构分析

Bearing loads of dual rotor-bearing system under stationary and transient conditions

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Journal of Beijing Institute of Technology 2012年第4期21卷 460-465页

作者：刘树辉王国丽朱清乐周年发陈勇 School of Mechanical engineering Beijing Institute of Technology Avic shenyang liming aero-engine (group) corporation Ltd

Aimed at aeroengine vibration failure, bearing loads of dual rotor-bearing system caused by unbalance are calculated under stationary and transient conditions. The three-dimensional （3-D） finite element method （FEM） model of dual rotor-bearing system was established. Applying the ro- tor dynamics function of Ansys 12.0, bearing loads were calculated under various unbalance force in stationary condition, and the transient vibration characteristics and the effect of acceleration on bearing loads were discussed. On the basis of simulation results, the influence disciplines of unbal- ance on bearing loads and theoretic reference for reducing bearing loads during start-up were ob- tained.

关键词： dual rotor-bearing system bearing loads rotor dynamics aeroengine

Electrochemical Behavior of Oxide Films of Stainless Steel in 40 kHz Sonicated Sulphate Electrolytes

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Chinese Journal of aeronautics 2007年第2期20卷 148-152页

作者： ZHU Li-qun LI Min-wei WANG Hui School of Materials Science and engineering Beij＇ing University of Aeronautics and Astronautics Beijing 100083 China shenyang liming aero-engine group corporation Shenyang 110043 China

This paper describes effects of 40 kHz ultrasound on the oxide films of stainless steel in sulphate electrolytes so as to determine the transmitted power and to characterize mass transfer and peak current density on the electrode surface. Emphasis was mainly laid on electrochemical oxidations and peeling mechanism of oxide films in sonicated sulphate solutions （0.5 and 1.0 mol/L）. Polarization voltammetry, current response traces and SEM analysis were carded out in order to provide full information as to oxide films surface. Results shows that the rate of electrochemical oxidation, the shape of polarization curves and the surface micrographs in sonicated sulphate electrolytes are different from those obtained without introduction of ultrasound. It is concluded that ultrasound can change the electro-chemical behavior of oxide films by its cavitaion effects, which would produce transient mechanical impulsive force and enhance electrochemical reactions.

关键词： stainless steel oxide films electrolysis ultrasound cavitation

Performance evaluation of creep feed grinding ofγ-TiAl intermetallics with electroplated diamond wheels

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Chinese Journal of aeronautics 2021年第6期34卷 100-109页

作者： Xinxin XI Wenfeng DING Zhixin WU Lama ANGGEI College of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China shenyang liming aero-engine Co. Ltd.Aero-Engine Corporation of ChinaShenyang 110043China

This paper evaluates the performance of creep feed grindingγ-TiAl intermetallic(Ti-45 Al-2 Mn-2 Nb)using electroplated diamond ***,a comparative analysis with the grinding results by using electroplated CBN wheels was conducted,mainly involving abrasive wheel wear behavior and maximum material removal rate below surface burn *** was found that the diamond wheel would produce much better grinding results including lower wheel wear rate and higher maximum material removal *** the surface integrity obtained at different level of material removal rate was characterized with the utilization of the diamond *** poor ductility of thisγ-TiAl intermetallic material was found to have a marginal effect on the surface integrity,as no severe surface defects such as material pullout were generated during the stable wheel wear *** the involved operating parameters,a deformation layer was produced with~10μm or more in thickness depending on the material removal rate ***,a work-hardened layer extending to more than 100μm was produced with a maximum microhardness of above 520 HV0.05(bulk value 360 HV0.05).The residual stress remained compressive,with a value of above-100 MPa and even up to-500 MPa for an elevated material removal *** chip was the main chip type,indicating good wheel sharpness in the grinding process.

关键词： Creep feed grinding Electroplated abrasive wheels Surface integrity Wheel wear γ-TiAl intermetallic

Effects of shot peening and laser remelting on oxygen-permeation treatment of titanium alloy

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中国有色金属学会会刊：英文版 2004年第z1期14卷 268-273页

作者： MA Hong-yan WANG Mao-cai WEI Zheng XIN Gong-chun State Key Laboratory for Corrosion and Protection Institute of Metal Research Graduate School of Chinese Academy of Sciences Beijing 100030 China State Key Laboratory for Corrosion and Protection Institute of Metal Research Graduate School of Chinese Academy of Sciences Beijing 100030 China Shenyang Liming Aero-engine Group Corporation Shenyang 110043 China Shenyang Liming Aero-engine Group Corporation Shenyang 110043 China

The influence of surface pre-treatments, shot-peening (SP) and laser remelting (LR), on oxygen permeation behaviors of titanium alloy TC11 was investigated. Optical microscope, SEM with EDAX, XRD, and microhardness tester were employed to characterize the microstructure, composition and hardness of this alloy. The results show that the surface roughness is increased by shot-peening, and the microstructure with fine-grain can be obtained by LR pre-treatment. The pre-treated samples were oxygen-permeated at (810± 10) ℃ for 10 h in atmospheric air. The outer layer consists essentially of TiO2, trace Ti2 N, Ti3Al and Ti3AlN for the SP pre-treatment and thin oxygen solution layer is found in the subsurface layer. As for LR pre-treatment, the outer layer consists mainly of TiO2 and small amounts of TiO, and the inner layer consists of alpha crystals, rich in interstitial atoms. Samples by LR pre-treatment has thicker hardened layer with higher hardness values in comparison with SP pre-treated *** boost diffusion of oxygen and hardening mechanisms were discussed based on the experimental results.

关键词： shot peening laser remelting oxygen-permeation titanium solution

Complicated hollow turbine blades and surface grain refinement process

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China Foundry 2010年第2期7卷 121-126页

作者： Peng Zhijiang Jia Shuqin Zhang Zehai Liu Yan AVIC shenyang liming aero-engine （group） corporation Ltd Shenyang 110043 shenyang Research Institute of Foundry Shenyang 110022 China

The control of grain size in superalloys is critical in the manufacture of gas turbine *** aim of the present research is to provide the technology for producing complicated hollow turbine blades with fine surface grains and better comprehensive mechanical *** melt superheating treatment and coating the internal surfaces of shell mould using a cobalt aluminate-bearing coating material,the in-uence of cobalt aluminate as inoculant on the surface grain sizes of turbine blade was studied with addition of cobalt aluminate:0,35%,45%-65% and 100% *** the same time,the effects of cooling circumstances of the blades on surface grain sizes were also experimented under the same addition of cobalt *** results showed that the melt superheating treatment plays a significant role in the grain size and carbide morphology;and fine surface grains were obtained when the internal surfaces of shell mould were coated using cobalt aluminate *** the addition of cobalt aluminate in coating is between 45%-65%,and the melt is poured into preheated shell moulds with fine silica sand as backing sand,the blades satisfied the surface grain size requirement is over 90%.In addition,comparisons of the surface grain size and the mechanical properties were also conducted between home-made and foreign-made blades.

关键词： complicated hollow turbine blades K465 alloy surface grain refinement melt superheating treatment

Cyclic oxidation behavior of β-NiAlDy alloys containing varying aluminum content at 1200℃

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Progress in Natural Science:Materials International 2012年第4期22卷 311-317页

作者： Dongqing Li Lu Wang Hui Peng Xiaoyu Zhao Hongbo Guo Shengkai Gong School of Materials Science and engineering Beihang University shenyang liming aero-engine group corporation Ltd. AVICShenyang 110043China

β-NiAlDy cast alloys containing varying aluminum content were prepared by arc-melting. The microstructures and cyclic oxidation behavior of the alloys at 1200 ℃ were investigated. Grain refinement was achieved by increasing aluminum content in the alloy, which is beneficial to selective oxidation. The Ni-55Al-0.1Dy alloy showed excellent cyclic oxidation resistance due to the formation of a continuous, dense and slow-growing oxide scale. In contrast to this, severe internal oxidation as well as large void formation at the scale/alloy interface occurred in the Ni-45Al-0.1Dy alloy. The aluminum content dependence of the reactive element effects in β-NiAlDy was established that Dy doping strengthened the scale/alloy interface by pegging mechanism in high-aluminum alloys but accelerated internal oxidation in low-aluminum alloys during high-temperature exposure.

关键词： β-NiAl Reactive elements Dysprosium Aluminum content High-temperature oxidation