航空材料学报

2021, 41(5): .

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Abstract:

Research progress on spectrally selective radiation infrared stealth materials

WANG Xinfei, LIU Dongqing, PENG Liang, CHENG Haifeng

2021, 41(5): 1-13.

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Abstract:
The continuously developing infrared detection technology and precise guidance technology pose an increasingly serious threat to the survival and penetration of missiles, hypersonic aircraft and other weapons and equipment. Infrared stealth technology plays an increasingly important role in modern warfare. Traditional low-emissivity coating materials usually have low emissivity characteristics in the entire infrared band and do not have spectral selectivity. This causes a poor effect on radiative cooling, which is not conducive to the reduction of the overall infrared signal of the target. Spectrally selective radiation infrared stealth materials can reduce the emissivity of atmospheric windows (3-5 and 8-14 µm), while using non-atmospheric window (5-8 µm) for radiative cooling. They have more efficient infrared stealth performance, thus attracting a lot of attention currently. This article introduces the research status and progress of three-generation spectrally selective radiation structures, which are based on photonic crystals, frequency selective surfaces and Fabry-Perot cavities respectively, summarizes their advantages and problems. At present, the spectrally selective radiation infrared stealth material is still far from practical application. In the future, it should continuously develop in the direction of simpler technology, stronger high-temperature stability and multiband compatibility.

Research progress and development trend of fiber-reinforced ceramic matrix composites

ZHANG Menghua, PANG Zixuan, JIA Yunxiang, LI Juncaoyi, SHAN Chenwei

2021, 41(5): 14-27.

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Abstract:
Fiber-reinforced ceramic matrix composites have many excellent mechanical properties for their high specific modulus, high specific strength, low coefficient of thermal expansion, high temperature resistance, corrosion resistance and wear resistance. Due to these properties, fiber-reinforced ceramic matrix composites have been widely applied in aerospace and other fields. However, fiber-reinforced ceramic matrix composites are difficult to machine due to their heterogeneity, anisotropy, high hardness and brittleness. Therefore, it is necessary to conduct in-depth research on the machining mechanism of this kind of composites. This paper systematically reviews the research status of conventional machining method and non-conventional machining method of fiber-reinforced ceramic matrix composites. It also generalizes the development trend, advantages and disadvantages, application scope, existing problems, and corresponding solutions of various machining methods. Compared with the conventional machining method, non-conventional machining method has obvious advantages, which is the main direction of development at present.

Anti-sand erosion and anti-icing coating for leading edge of airfoil based on silicone modified polyurethane elastomer

YU Mingming, ZHANG Yi, LIANG Lu, WANG Zhiyong

2021, 41(5): 28-34.

[Abstract](274) [FullText HTML] (128) [PDF 737KB](45)

Abstract:
The anti-sand erosion and anti-icing coating technique is highly demanded in the leading edge of the airfoil surface. Herein, an anti-sand erosion and anti-icing coating (Si-PUEc) based on the silicone-modified polyurethane elastomer (Si-PUE) was fabricated and its hydrophobicity, tensile property, sand erosion resistance and anti-icing performance were investigated. The polyurethane elastomer was synthesized by a polyaddition reaction of hydroxy-terminated polyolefin resin and polyolefin resin as soft segments with isophorone diisocyanate and 1,4-butanediol as hard segments. The research results show that the Si-PUEc with a high water contact angle (WCA) of 108° exhibits a weak ice adhesion strength of 68.04 kPa, less than a third of that of the original bare aluminum plate surface (235.26 kPa). Moreover, the tensile strength of Si-PUEc is 14.03 MPa and the elongation at break is 370%, showing excellent tensile properties. After the sand and dust test, the surface of Si-PUEc is intact, without damage, cracking and other defects of the film, and the WCA remains at 108°. Before and after the damp-heat test, the hydrophobic performance, anti-icing performance, and stress-strain performance of Si-PUEc are not changed significantly. The distinctive composition and morphology of the polyurethane elastomer serves as the key that opens up a new strategy to design hydrophobic coatings for robust and durable anti-sand erosion and anti-icing coating applications in the leading edge of the airfoil surface.

Effects of small addition of Sc on microstructure and mechanical properties of X2A66 alloy

XIONG Chun, XIAO Kai, GUAN Ruichun, XU Jinjun, TANG Qidong, JIANG Mang

2021, 41(5): 35-43.

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Abstract:
The effects of Sc addition on the microstructure evolution and mechanical properties of X2A66 alloy were studied by the experimental methods of mechanical property test and microstructure characterization. The results indicate that adding 0.18% Sc element in the X2A66 alloy can effectively refine the grain size, and form the primary phase of AlScZr or AlCuScZr with larger size, and also increases the over firing temperature of the as-cast alloy. Compared with Al₃Zr particles, Al₃(Sc, Zr) composite particles have better effect on restraining recrystallization, and make the alloy have smaller grain size during the subsequent deformation and heat treatment. However, AlCuSc and AlCuScFe phases can not be completely dissolved in the subsequent heat treatment process, which damages the mechanical properties of the solid solution alloy.

Investigation on hot deformation behavior of 2050 Al-Cu-Li alloy

MA Xiaoguang, YANG Yuyan, LUO Rui, XU Yanjin, CAO Yun, ZENG Yuansong

2021, 41(5): 44-50.

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Abstract:
In this paper, Gleeble-3500 thermal simulator was employed to perform single-pass isothermal compression tests of a spray formed 2050 Al-Cu-Li alloy at a temperature range of 350 to 470 ℃ and a strain rate range of 0.01 to 5 s⁻¹. The flow stress curves of the alloy were captured and the flow data were made into 3D hot processing map subsequently as a guidance for industrial production. At the same time, EBSD technique was applied to characterize the evolution of hot deformation microstructure of the alloy. The results show that the flow stress of the alloy increases with the decreasing deformation temperature and rising strain rate. 3D hot processing map shows that the dissipation power of the alloy has two peaks, and the optimal hot working interval is from to 450-470 ℃, 0.01 - 0.1 s⁻¹. The microstructure analysis of EBSD shows that the original grains of the alloy are significantly elongated after hot deformation, and a large number of recrystallized grains are found in the intergrain and grain boundary of the alloy at 470 ℃/0.01 s⁻¹, which indicates that the alloy has good hot working performance under such deformation conditions.

Constitutive model and hot workability of 2195 Al-Li alloy based on stress correction

ZHAO Yifan, WU Wenke, HE Guoai, WANG Qiang

2021, 41(5): 51-59.

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Abstract:
The isothermal compression tests of 2195 Al-Li alloy annealed at 400 - 490 ℃ and strain rate 0.01-10s⁻¹ were carried out. The true stress-strain curve obtained from the experiment was modified by friction force and temperature rise effects, and the constitutive relationship was established based on the modified true stress-strain curve. The results show that the correlation coefficient R is 0.99584, and the mean absolute error (AARE) is only 3.698%, which indicates that the constitutive model can well predict the flow stress of 2195 Al-Li alloy under different deformation parameters. Furthermore, based on the modified stress-strain data, the activation energy processing diagram (AEP) is established by coupling the rheologic instability diagram(conventional hot processing map, CHP) with the activation energy value Q, and the hot-working window of the alloy is optimized as follows: the strain rate is less than 0.4 s⁻¹, and the temperature is 475-490 ℃. The constitutive relationship and activation energy thermal processing diagram of 2195 Al-Li alloy established based on the modified stress and strain can lay a good foundation for the finite element simulation of the 2195 Al-Li alloy rheological process and the formulation of processing parameters.

Analysis of influencing factors on forming limit of GH605 sheet metal

WANG Yanju, LUAN Wei, MENG Bao, SHA Aixue, JIA Chonglin

2021, 41(5): 60-68.

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Abstract:
Sheet metal forming limit diagram (FLD) is a comprehensive index used to evaluate sheet metal formability. In this paper, the forming limit curves of GH605 sheet materials with 0.2 mm and 2.5 mm thickness under three different heat treatment conditions were obtained by numerical simulation of bulging. Then, the simulated forming limit results of the three materials with 0.2 mm thickness were compared with the experimental results. The results show that the simulated FLDs can be in good agreement with the experimental FLDs. The influences of work hardening index (n value) and anisotropy index (r value) on the forming limit are analysed from the view of material property difference. The comprehensive simulated and experimental results show that the formability of the sheets after the two kinds of solution treatment is significantly better than that of the annealed sheets. The forming limit curve increases with the increase of n value and r value, and the influence of n value on the forming limit curve is more significant than that of r value. The forming limit diagram established by numerical simulation can provide a theoretical basis for material development and process selection.

Influence of constitutive model on calculation results of creep deformation response of notched specimen of GH4169 alloy

HU Xianming, JI Dawei, ZHUANG Shuying, HU Xuteng

2021, 41(5): 69-77.

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Abstract:
In view of the creep deformation failure of areo-engine high temperature components, the elastoplastic and creep deformation response of GH4169 alloy smooth and notched plate specimens at 650 ℃ is calculated using elastoplastic coupled creep constitutive model based on the large deformation finite element analysis, to explore the influence of creep constitutive model selection on creep deformation response and creep rupture life calculation. The results show that the elastoplastic deformation response of notched plate specimens is well predicted by large deformation analysis, the elastoplastic deformation and ultimate strength of the three notched plate specimens are all well predicted, and the prediction error of ultimate strength is within ± 3%. Three creep models have different predictive effects on creep response and creep rupture life of notched plate specimens under large deformation finite element analysis. The θ-projection model is found to predict the rupture life of notched specimens more accurately within the factor of ± 2. While the modified creep model and the Batsoulas model can predict the deformation of the first two creep stages more accurately.

Microstructure and mechanical properties of wide gap brazing joint of the third-generation nickel-based single crystal superalloy

LI Kexin, HOU Xingyu, WANG Shiyang, SUN Yuan, CHEN Lijia, CHENG Lufan, WANG Zhenjiang, LI Hansong, TANG Guangquan

2021, 41(5): 78-85.

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Abstract:
In this study, the third-generation rhenium containing single crystal superalloy was brazed by mixed powder filler, in which the mixed powder filler was consisted of nickel-based powder filler and the superalloy powder with the same composition of the base metal. SEM and EPMA were used to analyze the influence of the proportion of the third-generation single crystal superalloy powder in the mixed filler on the microstructure of the joint, and the high temperature stress rupture properties of the brazed joint with four kinds of solder were tested. The result indicates that the microstructures and phase compositions of the Ni-based powder filler and mixed powder filler are both consisted of γ-Ni, γ′, CrB, Ni₃B and M₃B₂ type boride, but the residue of the mixed powder filler is molten ball-type superalloy. With the thickness of brazing gap constant and increasing the ratio of the third-generation single crystal superalloy powder in the mixed filler, the precipitation of M₃B₂ type boride and low-melting point phases in the joint can be inhibited, and the distribution of borides becomes more uniform and the size becomes smaller, thus improving the uniformity of the composition and microstructure of the joint. When the proportion of alloy powder increased from 0% to 50%, the endurance life of the joint increased from 15 min to 34 hours. However, when the proportion of alloy powder increased to 60%, there are a lot of void defects in the joint, resulting in the endurance life of the joint decreased to 4 hours.

Microstructure and electrochemical properties of laser cladding C276 coating on 300M steel

CUI Jing, XUE Anyuan, LIU Ling, XIA Haiyang, YANG Guangfeng

2021, 41(5): 86-93.

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Abstract:
IIn order to improve the corrosion resistance of 300M steel surface, NCLT was used in cw-1k solid-state Nd: YAG laser system, Hastelloy C276 coating with 800W laser power and 8 mm/s scanning speed was prepared on the surface of cw-1k solid-state Nd: YAG laser system. The macro morphology, microstructure, phase composition, microhardness, friction and wear properties and electrochemical properties of C276 coating were tested. The results show that the microhardness of C276 coating is increased by 1.4 compared with the substrate. However, the wear resistance of the coating is lower than that of the 300M steel substrate, the corrosion potential of the coating is the highest, the self - corrosion current density is the smallest. The C276 coating is prepared on the surface of 300M steel by laser cladding technology, which significantly improves the corrosion resistance of 300M steel surface, and provides a new scheme for improving the corrosion resistance and corrosion resistance of the material surface.

Stability of interface between MgO and carbon nanotubes

LIAO Lin, YUAN Shaotao, ZHOU Jiajun, MA Guangxiang, CHEN Yanyuan, YUAN Qiuhong

2021, 41(5): 94-102.

[Abstract](314) [FullText HTML] (71) [PDF 1631KB](28)

Abstract:
In this work, MgO-coated carbon nanotubes (MgO@CNTs) were synthesized via the co-deposition technique. The samples of MgO@CNTs were treated by using the high power ultrasonic vibration with a long time to verify their structural stability. Microstructure of the CNTs and MgO@CNTs was characterized by using the FI-IT spectra analysis, scanning electron microscope and transmission electron microscope. The experiment result reveals that the high power ultrasonic vibration and the long-time ultrasonic-treatment can easily cut off the CNTs, while the MgO nanoparticles are still tightly adsorbed on the surface of CNTs without removing away from the surface of CNTs by the ultrasonic vibration. It means that MgO@CNTs is a novel reinforcement for the Mg-based composite because the MgO nanoparticles and CNTs have formed a good interface bonding with high stability. Simultaneously, the stable interfacial bonding between MgO and CNTs is explained by the first- principle calculation.

2021 Vol. 41, No. 5