检索结果-南通市图书馆

China Foundry 2019年第1期16卷 14-22页

作者： Qiang Gao Li-rong Liu Xiao-hua Tang Zhi-jiang Peng Ming-jun Zhang Su-gui Tian School of Materials Science and engineering Shenyang University of TechnologyShenyang 110870China aecc shenyang liming aero engine co.ltd. Shenyang 110043China

Interfacial dislocations found in single crystal superalloys after long term thermal aging have an important effect on mechanical properties. Long term thermal aging tests for DD5 single crystal superalloy were carried out at 1,100 ℃ for 20, 100, 200, 500 and 1000 h, and then cooled by air. The effect of long term thermal aging on the dislocation networks at the γ/γ' interfaces was investigated by FE-SEM. Results showed that during the long term thermal aging at 1,100 ℃, misfit dislocations formed firstly and then reorientation in the(001) interfacial planes occurred. Different types of square or rectangular dislocation network form by dislocation reaction. Square dislocation networks consisting of four groups of dislocations can transform into octagonal dislocation networks, and then form another square dislocation network by dislocation reaction. Rectangular dislocation networks can also transform into hexagonal dislocation networks. The interfacial dislocation networks promote the γ' phase rafting process. The dislocation networks spacings become smaller and smaller, leading to the effective lattice misfit increasing from-0.10% to-0.32%.

关键词： DD5 single crystal superalloy interfacial dislocations long term thermal aging effective lattice misfit

Error modeling and compensating of a novel 6-DOF aeroengine rotor docking equipment

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2022年第6期35卷 312-324页

作者： Tianyi ZHOU Hang GAO Xuanping WANG Lun LI Qing LIU Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education Dalian University of TechnologyDalian 116024China aecc shenyang liming aero-engine co. LtdChina

In the docking process of aeroengine rotor parts,docking accuracy that indicates the gaps between the end faces is strictly required.A key issue is improving docking accuracy using automated docking *** this paper,a systematic study is carried out on the error modeling and compensation of a novel six-degrees-of-freedom(6-DOF)docking equipment for aeroengine ***,a new model for indicating the main indexes of docking accuracy is ***,the error model of a specially designed 6-DOF docking equipment is established based on a modified Denavit Hartenberg method with five ***,two error compensation methods are *** on the above models,a docking accuracy simulation algorithm is proposed using the Monte Carlo ***,verification experiments are *** results show that,for the maximum values and standard deviations of the gaps between the rotor end-faces in the actual and target positions and attitudes,i.e.,main indexes that represent docking accuracy,the deviation rates between the simulation and experimental results are less than20%.The modeling methods have referential *** decline rates of these values are 50–65%when using the two proposed compensation *** compensation methods significantly improve the docking accuracy.

关键词： Accuracy analysis aeroengine rotor Docking Error compensation Error models Multi-degree-of-freedom structures

Experimental investigation of laser peening on TiAl alloy microstructure and properties

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2015年第2期28卷 609-616页

作者： Qiao Hongchao Zhao Jibin Gao Yu shenyang Institute of Automation Chinese Academy of Science AVIC shenyang liming aero-engine (Group) corporation ltd.

In order to study the effect of laser peening on microstructures and properties of TiAl alloy, TiAI alloy samples were treated by Nd：YAG laser system with the wavelength of 1064 nm, pulse-width of 18 ns, and pulse-energy of 0-10J. Surface micro-hardness, roughness, and microstructural characteristics were tested with micro-hardness tester, roughness tester and scanning electron microscope. Residual stress and pole figures were tested with X-ray diffraction and its high-temperature stability was analyzed. The experimental results show that surface micro-hardness increases by up to 30%, roughness increases to 0.37 lain, compressive residual stress increases to 337 MPa, and local texture and typical lamellar microstructure are generated. Residual stress, micro-hardness, and （002） pole figures tests are conducted, compressive residual stress value drops from 337 MPa to 260 MPa, hardness value drops from 377 HV0.2 to 343 HV0.2, and the （002） poles shift back to the center slightly. Laser peening improves microstructure and properties of TiAl alloy significantly.

关键词： High temperature stabilityLaser peening Microstructure Residual stress TiAl alloy

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

在线全文

学校读者我要写书评

暂无评论

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

High-performance grinding of ceramic matrix composites

在线全文

学校读者我要写书评

暂无评论

Nanotechnology and Precision engineering 2024年第3期7卷 45-55页

作者： Jingfei Yin Jiuhua Xu Honghua Su college of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Technology Center AECC Shenyang Liming Aero-engine Co.Ltd.Shenyang 110043China

Ceramic matrix composites(CMCs)are highly promising materials for the next generation of ***,machining of CMCs suffers from low efﬁciency and poor surfaceﬁnish,which presents an obstacle to their wider *** overcome these problems,this study investigates high-efﬁciency deep grinding of CMCs,focusing on the effects of grinding *** results show that both the sur-face roughness and the depth of subsurface damage(SSD)are insensitive to grinding *** material removal rate can be increased sixfold by increasing the grinding depth,while the surface roughness and SSD depth increase by only about 10%.Moreover,it is found that the behavior of material removal is strongly dependent on grinding *** the grinding depth is increased,ﬁbers are removed in smaller sizes,with theﬁber length in chips being reduced by about 34%.However,too large a grinding depth will result in blockage by chip powder,which leads to a dramatic increase in the ratio of tangential to normal grinding *** study demonstrates that increasing the depth of cut is an effective approach to improve the machining efﬁciency of CMCs,while maintaining a good surfaceﬁ*** provides the basis for the further development of high-performance grinding methods for CMCs,which should facilitate their wider application.

关键词： Ceramic matrix composite Grinding Surfaceﬁnish Subsurface damage Fiber breakage

Effect of Phosphorus on Mechanical Properties and Thermal Stability of Fine-grained GH761 Alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2011年第6期27卷 539-545页

作者： Shulin Yang Wenru Sun Jianxi Wang Zhimei Ge Shouren Guo Zhuangqi Hu Institute of Metal Research~ Chinese Academy of Sciences Shenyang 110016 China shenyang liming aero-engine corporations shenyang 110043 China

The effect of phosphorus on mechanical properties and thermal stability of fine-grained GH761 alloy has been *** results show that,when the content of phosphorus is in the range of 0.0007-0.040,there are no significant effects on the tensile *** strongly affects the stress rupture *** content of 0.023 P results in the longest life in this *** with that of the alloy with 0.0007 P,the life is increased more than 2 times in the alloy with 0.023 *** ageing at 700℃ for 1000 h,the life reduced to some ***,phosphorus exhibits the similar effect on the life as before *** tensile properties of the alloy are not influenced by long term ageing *** present results suggested that the optimum content of phosphorus is *** phosphorus with this content can optimize the precipitates at the grain boundaries and prevent the excessive growth of the *** combining mechanical properties of GH761 alloy can be largely improved by phosphorus addition combined with grain refinement.

关键词： Phosphorus Fine-grained Mechanical properties Ageing Grain boundaries

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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2009年第A3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

Development of a deviation package method for low-cost robust optimization in compressor blade design

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2024年第4期37卷 166-180页

作者： Mingzhi LI Xianjun YU Dejun MENG Guangfeng AN Baojie LIU Research Institute of aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&Technology on aero-engine aero-Thermodynamics Beihang UniversityBeijing 100191China aecc shenyang engine Research Institute Shenyang 110015China

Manufacture variations can greatly increase the performance variability of compressor blades. Current robust design optimization methods have a critical role in reducing the adverse impact of the variations, but can be affected by errors if the assumptions of the deviation models and distribution parameters are inaccurate. A new approach for robust design optimization without the employment of the deviation models is proposed. The deviation package method and the interval estimation method are exploited in this new approach. Simultaneously, a stratified strategy is used to reduce the computational cost and assure the optimization accuracy. The test case employed for this study is a typical transonic compressor blade profile, which resembles most of the manufacture features of modern compressor blades. A set of 96 newly manufactured blades was measured using a coordinate measurement machine to obtain the manufacture variations and produce a deviation package. The optimization results show that the scatter of the aerodynamic performance for the optimal robust design is 20% less than the baseline value. By comparing the optimization results obtained from the deviation package method with those obtained from widely-used methods employing the deviation model, the efficiency and accuracy of the deviation package method are demonstrated. Finally, the physical mechanisms that control the robustness of different designs were further investigated, and some statistical laws of robust design were extracted.

关键词： Manufacture variations Robust design optimization compressor leading edge aerodynamics Physical mechanism

Breaking the geometry-performance tradeoff in compressor deviation modeling:Nested principal component analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of aeronautics 2024年第9期37卷 131-149页

Uncertainties in the aerodynamic performance of compressors,introduced by manufacturing variations,have received more and more attentions in recent *** deviation model plays a crucial role in evaluating this uncertainty and facilitating robust ***,current deviation models with a few variables cannot simultaneously achieve a precise geometric approximation of deviation and provide an accurate assessment of performance *** paper introduces a novel deviation modeling method named Nested Principal component Analysis(NPCA)to break this *** this method,both geometry-based and performance-based modes are utilized to describe manufacturing *** considering aerodynamic sensitivity,surface deformations that significantly impact aerodynamic performance can be extracted for deviation *** demonstrate the superiority of this newly proposed method,ninety-eight newly manufactured compressor rotor blades were measured using a coordinate measurement machine,and both NPCA and Principal component Analysis(PCA)were employed to model the real manufacturing *** results indicate that,in comparison to the PCA method,the NPCA method achieves an equivalent level of accuracy in geometric reconstruction and evaluation of mean ***,the same level of accuracy can be obtained with eight NPCA modes and fifty PCA modes when assessing the scatter in aerodynamic ***,the working mechanism of the NPCA method for accurate uncertainty quantification was further investigated.

关键词： Manufacturing variation Uncertainty quantification Dimension reduction aerodynamics Flow mechanism