Shanghai Spaceflight Precision Machinery Institute
Shanghai Spaceflight Precision Machinery Institute
Ma Y.,Shanghai JiaoTong University |
Chen Y.,Shanghai JiaoTong University |
Li S.-H.,Shanghai JiaoTong University |
Peng H.-L.,Shanghai Spaceflight Precision Machinery Institute
Suxing Gongcheng Xuebao/Journal of Plasticity Engineering | Year: 2016
At 500℃,the creep tests were carried out at three stress levels 0.3σ0.2500℃,0.4σ0.2500℃and 0.5σ0.2500℃ for TB2 titanium alloy solution-treated for 30min at 800℃,air-cooled to room temperature. The new creep constitutive equations were established based on classic creep constitutive equation and Garofalo creep constitutive equation. The constitutive parameters in three creep constitutive equations were obtained by using Origin to fit the creep experimental data. The new creep constitutive equations can well describe the creep behavior of TB2 titanium alloy at different stresses by comparing the experimental results and computed creep curves. © 2016, Editorial Board of Journal of Plasticity Engineering. All right reserved.
Zeng K.-H.,National University of Defense Technology |
Li Z.-Q.,Shanghai Spaceflight Precision Machinery Institute |
Liang S.-L.,National University of Defense Technology |
Xiao L.,Shanghai Spaceflight Precision Machinery Institute |
Ma Q.-S.,National University of Defense Technology
Key Engineering Materials | Year: 2017
Mullite matrix composites with laminated and stitched carbon fiber cloth preform as reinforcement were fabricated via the route of "infiltration-drying-heat treatment" using Al2O3-SiO2 sol as raw materials. Thermal properties from room temperature to 1673K of the composites were investigated. The coefficient of thermal expansion (CTE) increases first and then decreases, and reaches a maximum of 4.83×10-6K-1 at 1273K. As a result of the further sintering of matrix, the CTE is negative at above 1300°C. The specific heat capacity increases to the maximum of 1.547J·g-1·K-1 at 1473K and remains stable at above 1473K, with a minimum of 0.756J·g-1·K-1 at room temperature. The thermal diffusivity decreases from 1.1mm2·s-1 at room temperature to 0.707 mm2·s-1 at 973K as the temperature was elevated, and remains stable at above 973K. On the contrary, the thermal conductivity is improved with increasing temperature on the whole and varies from 1.859W·m-1·K-1 at room temperature to 2.325W·m-1·K-1 at 1473K. © 2017 Trans Tech Publications.
Wang Y.,Dalian University of Technology |
Liu S.,Dalian University of Technology |
Liu C.,Shanghai Spaceflight Precision Machinery Institute |
Zhang H.-C.,Dalian University of Technology |
Zhang H.-C.,Texas Tech University
International Journal of Manufacturing Research | Year: 2017
Reliability assessment of centrifugal compressor impellers has been a critical issue in industrial practice and application. In this paper, cycling life of the impeller obtained by the fatigue test is substituted into the S-N formula to calculate a group of parameter b in the formula. Then b is fitted by a three-parameter Weibull distribution. After that, Monte Carlo method is used for random sampling from the three-parameter Weibull distribution. Every b acquired by the sampling is substituted back into the S-N formula, by which a large group of values of the cycling life are calculated to fit its distribution. The reliability of the impeller under operating condition is then obtained to provide a critical reference for the health monitoring of the centrifugal compressor impeller online. © 2017 Inderscience Enterprises Ltd.
Yin J.,Huazhong University of Science and Technology |
Wang D.,Huazhong University of Science and Technology |
Meng L.,Huazhong University of Science and Technology |
Ke L.,Shanghai spaceflight precision machinery institute |
And 2 more authors.
Surface and Coatings Technology | Year: 2017
Laser cladding is an effective way to improve wear resistance of copper alloys, however, low deposition rate is a main drawback that retards its industrial applications. Metal silicide based composite coatings were prepared on pure copper substrate by laser-induction hybrid cladding with a 5 kW fiber laser efficiently, and the powder feeding rate can reach 88.7 g/min. Cr13Ni5Si2, Cr3Ni5Si2 and Cu-based solid solution (Cuss) are main constituent phases in the composite coatings. Moreover, hardness of the different phases was evaluated by nanoindentation. Results indicated that the Cr13Ni5Si2 with high hardness (15.8 GPa) is acted as strengthen phase in the composite coatings, while the Cr3Ni5Si2/Cuss with good toughness are acted as toughness phases. Synergistic effect of the strengthen phase and the toughness phases endows the composite coating with excellent wear resistance, and dry slide wear resistance of the composite coating at 600 °C is 21.9 times higher than that of the stainless steel 1Cr18Ni9Ti. © 2016 Elsevier B.V.
Liu B.,Shanghai University |
Liu B.,Shanghai Key Laboratory of Mechanics in Energy Engineering |
Wei Q.,Shanghai Spaceflight Precision Machinery Institute |
Tu J.,Shanghai Spaceflight Precision Machinery Institute |
And 3 more authors.
Measurement Science and Technology | Year: 2017
In this study, a shearography system integrated with a coherent fiber-optic illumination and a fiber-optic imaging bundle is presented to inspect the quality of the interior surface of a cylindrical vessel for safety purposes. The specific optical arrangement is designed for the inspection of a certain area at a small working distance. The optical arrangement of the system was assembled and an aluminum honeycomb sample was evaluated to demonstrate the capability of the system. The important relationship between the image quality and the working distance, as well as the field of view, is discussed. The system has been applied for the inspection of the interior surface of a cylindrical vessel. The experimental results suggest that the shearography system integrated with optical and image fibers can effectively minimize the size of the inspection device and be capable of evaluating the interior surface of cylindrical structures. © 2017 IOP Publishing Ltd.
Yu Y.,Harbin Institute of Technology |
Zhang W.,Harbin Institute of Technology |
Dong W.,Shanghai Spaceflight Precision Machinery Institute |
Han X.,Aerospace Research Institute of Materials And Processing Technology |
And 3 more authors.
Materials and Design | Year: 2015
Heat treatment with different parameters were performed on the hot-hydrostatically extruded and swaged 3.5. vol.% TiBw/Ti6Al4V composites tubes. The results indicate that the primary α phase volume fraction decreases and transformed β phase correspondingly increases with increasing solution temperatures. The α. +. β phases will grow into coarse α phases when the aging temperature is higher than 600. °C. The hardness and ultimate tensile strength of the as-swaged TiBw/Ti6Al4V composite tubes increase with increasing quenching temperatures from 900 to 990. °C, while they decrease with increasing aging temperatures from 550 to 650. °C. A superior combination of ultimate tensile strength (1388. MPa) and elongation (6.1%) has been obtained by quenching at 960. °C and aging at 550. °C for 6. h. High temperature tensile tests at 400-600. °C show that the dominant failure modes at high temperatures also differ from those at room temperature. © 2015 Elsevier Ltd.
Wen L.,University of Science and Technology Beijing |
Yuan Y.,Shanghai Spaceflight Precision Machinery Institute |
Wang Y.,Harbin Institute of Technology |
Jin Y.,University of Science and Technology Beijing
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2015
The pure and Fe-containing nanocrystalline layers were fabricated on the surface of 2024 Al alloy by surface mechanical attrition treatment (SMAT) using ceramic balls and steel balls, respectively. The friction and wear properties of 2024 Al alloy before and after SMAT were investigated by sliding against a GCr15 steel ball of 5 mm in diameter at a load of 1.5 N. The results demonstrate that the surface nanocrystalline layers with average grain sizes of 49.2 and 52.1 nm can be obtained by using ceramic balls and steel balls, respectively, when treated for 30 min. Moreover, a 5 μm thick surface layer containing Fe is also introduced into the Al nanocrystalline surface when treated using steel balls. The wear resistance of 2024 Al alloy is improved due to the combination of grain refinement, increased hardness and lubrication effect of iron-containing layer. Copyright © 2015, Northwest Institute for Nonferrous Metal Research. Published by Elsevier BV. All rights reserved.
Xu X.,Shanghai Spaceflight Precision Machinery Institute |
Li J.,Harbin Institute of Technology
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2014
To promote the defective craft in non-circular grinding NC system, a special NC system for non-circular grinding is presented based on CPAC. First, on the basis of piecewise cubic spline fitting as mathematical foundation, the cutter center coordinates of X-Y is calculated. Second, the importance of constant speed grinding is produced, and two algorithms based on constant length of arc interpolation are put forward to realize constant speed grinding. Third, the method of error measuring and compensation is given. Finally, integrated system is completed and applied to three-axis milling machine. The experiment proves that the system can meet the needs of non-circular grinding. ©, 2014, Harbin Institute of Technology. All right reserved.
Wang H.-D.,Shanghai Spaceflight Precision Machinery Institute |
Luan Q.-L.,Zhejiang University |
Chen Z.-W.,Zhejiang University |
He H.-N.,Hangzhou ECON Science and Technology Co.
Zhendong yu Chongji/Journal of Vibration and Shock | Year: 2015
Through studying the control algorithm for multi-exciter PSD (power spectral density) replication vibration tests, an identification strategy for the frequency response matrix of a vibration test system based on partial coherence analysis was designed. For situations of singular points existing in a system frequency response matrix and the matrix being rectangular, different system decoupling algorithms were desgined based on the solutions to the matrix generalized inverse and its Moore-Penrose inverse with the minimum norm and least square methods. Aiming at the situation that the system APSD (auto-power spectral density) might be negative or zero in the traditional difference correction of the drive spectral control algorithm, an improved PSD equalization control strategy was designed by introducing a proportional RMS feedback correction algorithm. The algorithm could effectively avoid the APSD being negative and zero in the process of PSD equalization. The multi-exciter PSD replication vibration tests showed that the improved PSD equalization control strategy can achieve a reliable, high-precision control effect on a multi-exciter vibration system. ©, 2015, Chinese Vibration Engineering Society. All right reserved.
Dong W.-Q.,Shanghai Spaceflight Precision Machinery Institute |
Zhang X.-L.,Shanghai Spaceflight Precision Machinery Institute
Suxing Gongcheng Xuebao/Journal of Plasticity Engineering | Year: 2014
The FLDs of the aerospace sheet metal materials of 1Cr18Ni9Ti stainless steel, 7A09, 5A06, 2A14, 2A12 aluminum alloy and TC4 titanium alloy are studied by the experiments. The FLD calculating models of 1Cr18Ni9Ti, 5A06, 2A14 and 2A12 are established based on the experimental data. The experimental study shows that the formability of 1Cr18Ni9Ti is much better than those of 5A06, 2A14 and 2A12 under room temperature, also the thickness of the sheet metal affects its forming limitation a lot. The thinner the sheet is, the lower of the forming limitation becomes. The formability of 7A09 aluminum alloy and TC4 titanium alloy are too bad to obtain their FLD under room temperature.