航空材料学报

2019-03目录

2019, 39(3): .

[Abstract](2639) [FullText HTML] (1425) [PDF 1007KB](27)

Abstract:

Research progress on SiCN ceramic prepared at low temperature by chemical vapor deposition

Yangyang MU, Jianyong TU, Jimei XUE, Fang YE, Laifei CHENG

2019, 39(3): 1-9.

[Abstract](5831) [FullText HTML] (2920) [PDF 2127KB](52)

Abstract:
Chemical vapor deposition (CVD) is a new technology for preparing inorganic materials which possess some advantages, such as lower preparation temperature, uniform and compact microstructure, and near-size molding, so it is one of the common methods to prepare functional ceramics. In the paper, several common chemical vapor deposition methods like atmospheric chemical vapor deposition, low-pressure chemical vapor deposition, plasma-enhanced chemical vapor deposition and laser-assisted chemical vapor deposition are reviewed, because the microstructure and performance of functional ceramics are greatly influenced by their fabrication methods. In addition, the deposition parameters of Si-C-N absorbing ceramics which are deposited at lower temperature by low-pressure chemical vapor deposition are optimized. It is proposed that low-pressure chemical vapor deposition is the main method for preparing the advanced EMW absorbing ceramics.

Progress in functionalization, hybridization of polyhedral oligomeric silsesquioxanes（POSS）and its application in modified epoxy resin

Sheng YANG, Kelong CHEN, Zhiyong WANG, Tong ZHANG, Yi CUI

2019, 39(3): 10-24.

[Abstract](3050) [FullText HTML] (1177) [PDF 1095KB](63)

Abstract:
Polyhedral oligomeric silsesquioxanes (POSS) has a unique structure and good heat resistance. After the function- alization of POSS, a new type of organic-inorganic hybrid material with high performance can be obtained, which has potential application value in many fields. This paper reviews the related issues of the synthesis and functionalization of POSS. Many types of POSS are widely used, but the relatively expensive price limits the development scale of POSS in many fields. POSS can be used as the modifier of epoxy resin, which has obvious strengthening and toughening effects, and significantly improves the heat resistance of cured epoxy resin. However, due to the nanometer size effect of POSS, the addition amount of POSS in the resin is limited. In the future , with the cost reduction of POSS synthesis and the continuous improvement of the means to modify the resin, the application scope of POSS in the modification field of thermosetting resin will be expanded.

Current situation of research on test methods for elastic modulus and Poisson’s ratio of single crystal superalloys

Pengtao ZHAO, Huichen YU, Yuhuai HE

2019, 39(3): 25-34.

[Abstract](3052) [FullText HTML] (1357) [PDF 721KB](79)

Abstract:
In view of the anisotropic characteristics of elastic constants of single crystal superalloys and other materials, this paper summarizes two main existing testing methods for measuring elastic moduli and Poisson’s ratio of single crystal superalloys: static method and dynamic method, and analyses the research status of elastic moduli and Poisson’s ratio of single crystal superalloys both at home and aboard. Also, the main problems and feasible solutions in current research both at home and abroad are summarized. And it is pointed out that there is no special testing standard for the elastic moduli and Poisson's ratio of single crystal superalloys. Compared with foreign countries, there is still an obvious gap in the testing and characterization technology in China, and effect of crystal orientation on elastic moduli and Poisson's ratio is often neglected in engineering applications. So it is necessary to estimate the influence of errors in measuring elastic constants of single crystal alloys by exiting testing standards. Meanwhile, this paper describes how to establish the quantitative relationship between crystal elastic moduli and arbitrary crystal orientation for single crystal superalloy DD6 through linear regression analysis of crystal orientation index and elastic moduli.

Experiment and simulation of thermomechanical coupled behavior of SMA under low velocity impact

Xuanchang REN, Jun WANG, Yingjie XU, Weihong ZHANG

2019, 39(3): 35-43.

[Abstract](2587) [FullText HTML] (1480) [PDF 1389KB](42)

Abstract:
The thermomechanical coupled behaviour of shape memory alloy (SMA) sheet under low velocity impact loading was investigated. Based on the SMA thermomechanical constitutive model, the impact response of SMA sheet was numerically simulated in software to explore the characteristics of SMA thermomechanical coupled behaviour under impact load.The numerical simulation results are in good agreement with the experimental data, which effectively characterizes the thermomechanical coupled behaviour, such as deformation, phase transformation, dissipation and temperature change, etc. during the impact of SMA sheet.

High temperature compression deformation behavior of TB17 titanium alloy

Hongchang ZHU, Junming LUO, Zhishou ZHU

2019, 39(3): 44-52.

[Abstract](2815) [FullText HTML] (1510) [PDF 1744KB](115)

Abstract:
The high temperature hot deformation behavior of TB17 titanium alloy was studied using Gleeble-3800 thermo-compression simulation tester at the temperature of 860 -980 ℃, strain rate of 0.001-1 s^–1 and the deformation degree of 0.7. The deformation behavior and microstructure were studied. By building the relationship between material parameters and true strain, the relationship between flow stress and deformation temperature, strain rate and strain was established by using Arrhenious constitutive equation and Z parameter. The results show that TB17 titanium alloy is more likely to happen continuous dynamic recrystallization at strain rate of 0.001-0.01 s^–1 and deformation temperature of 890-980 ℃, while discontinuous dynamic recrystallization occur mainly at high strain rate (≥ 0.1 s^–1). The error analysis shows that the average relative error between calculated and measured values is 6%. It indicates that the constitutive relation model has higher accuracy.

Effect of pouring system on shrinkage porosity of TiAl alloy rod castings by centrifugal casting

Haitao HU, Xiwen ZHANG, Chunlei ZHU, Sheng LI, Ji ZHANG

2019, 39(3): 53-61.

[Abstract](2368) [FullText HTML] (1400) [PDF 997KB](35)

Abstract:
Numerical simulation was used to study the influence of the diameter and riser structure of rod castings on the shrinkage porosity of TiAl alloy rod castings by centrifugal casting. The reasons for the influence were analyzed according to the filling and solidification temperature fields. The results indicate that the diameter of rod castings is increased from 16 mm to 20 mm, the diameter of the entrance area is further designed into 20 mm, and the diameter of the distal end is 16 mm, the tendency for blocking the rod casting filler channel is gradually reduced, the temperature of the molten metal for feeding is increased, and the solidification time is gradually increased. Thus the feeding effect is increased, and the level of shrinkage porosity is gradually reduced. Based on the conical design of rod castings, compared with the rod castings without risers, the added ring-shaped riser causes the sequential solidification tendency of the molten metal during filling weakened, the temperature of the molten metal for feeding during solidification decreased, and the solidification time shortened. Thus the feeding effect is decreased, and the level of shrinkage porosity is slightly increased. With adding the cone-shaped riser, the sequential solidification tendency of the molten metal during filling is enhanced, the temperature of the molten metal for feeding during solidification is increased, and the solidification time is increased. Thus the feeding effect is improved, and the level of shrinkage porosity is decreased. The pouring test of the casting is carried out with the best design. The average value of the maximum shrinkage porosity of the section of rod castings is basically the same as that of the simulation test.

Effect of solid solution temperature on microstructure of Hf-containing K416B Ni-based superalloy with high W-content

Guichen HOU, Haijun SU, Jun XIE, Shuling XUN, Jinjiang YU, Xiaofeng SUN, Yizhou ZHOU

2019, 39(3): 62-68.

[Abstract](2576) [FullText HTML] (1442) [PDF 4760KB](56)

Abstract:
By means of microstructure observation on Hf-containing K416B Ni-based superalloy with high W-content after solid solution heat treatment at different temperatures, the effect of solid solution temperature on microstructure of the alloy was investigated. The results show that with the increasing of solid solution temperature, the size of secondary dendrite increases slightly by element diffusion, and the eutectic content decreases gradually to promote the densification of alloy microstructure. In addition, the γ′ phase is dissolved into the matrix, and its size is decreased. During high temperature solid solution heat treatment, the primary strip MC phase in the inter-dendrite is decomposed to form granular M₆C carbides, while the morphology and quantity of large sized block M₆C phase in eutectic have no obvious change. The solid solution treatment causes that the element W is segregated in the dendrites to diffuse into inter-dendrites, and elements of Hf, Nb, Ti and Cr diffuse into the dendrites, the segregation degree of each element of the alloy is greatly reduced. The results of microstructure research indicate that the optimal solid-solution heat treatment process for the alloy is 1220 ℃ × 4 h.

Preparation and properties of new poly (methylphenyl silylene aryl ether arylacetylene) resin

Qi NIU, Junkun TANG, Chuan LI, Jiawei LUO, Xiaotian LIU, Qiaolong Yuan, Farong HUANG

2019, 39(3): 69-74.

[Abstract](2655) [FullText HTML] (1507) [PDF 821KB](45)

Abstract:
A poly (methylphenyl silylene aryl ether arylacetylene) (PSEA-P2) resin was synthesized from 1, 4-bis (4’-ethynylphenoxy) benzene and methylphenyldichlorosilane through Grignard reaction. The carbon fiber reinforced PSEA-P2 resin composite was also prepared. The structure of the resin was characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. The thermal behaviour of the resin was examined by differential scanning calorimetry. The glass transition temperature and heat resistance of PSEA-P2 resin were examined by dynamic thermomechanical analysis and thermogravimetric analysis respectively. The results show that the glass transition temperature and the degradation temperature in N₂ are higher than 450 ℃ and 531 ℃ respectively. The processing performance was determined by rotational rheological analysis. The results show that the processing window of PSEA-P2 resin is in the temperature range of 110-175 ℃, which is suitable for compression molding. The cured resin has excellent mechanical strength and heat resistance. The flexural strength of the cured resin is 54.3 MPa. The flexural strength of T300 carbon fiber reinforced composite can reach 518.0 MPa at room temperature, and its retention rate at 400 ℃ is 53%. The good mechanical strength of PSEA-P2 resin is due to the polar aryl ether bonds in molecular chain which enhances the bonding force between the resin and the fiber. On the other hand, the degree of crosslinking after curing is appropriate which reduces the decrease of mechanical properties caused by excessively high degree of crosslinking.

Preparation and properties of BAS/SiC complex phase ceramic materials

Xiaobo YANG, Zhiqiang SUN, Bingqing ZHANG, Zhenjiang MIAO, Huadong WANG, Yi LYU

2019, 39(3): 75-80.

[Abstract](2847) [FullText HTML] (1394) [PDF 12291KB](26)

Abstract:
Celsian was synthesized in situ and was used to sinter silicon carbide. The low temperature pressureless liquid sintering process for BAS/SiC complex phase ceramics was studied, and ceramic materials with high density were prepared. The effect of sintering temperature and content of BAS on density, structure and mechanical properties of the ceramics were investigated. The densification and microstructures of BAS/SiC ceramics were observed by scanning electron microscope. The crystalline phase of the composite ceramics was identified by X-ray powder diffraction. The results show that celsian is synthesized at the temperature of 1800 ℃, and BAS/SiC ceramics are prepared with density of 3.2 g/cm³. BAS is precipitated in hexagonal structure, and SiC particles are distributed uniformly in the composite ceramic. The flexural strength and fracture toughness of composite ceramics are decreased due to grains growth while the sintering temperature is above 1800 ℃. When the mass content of BAS reaches 30%, the typical flexural strength, elastic modulus and fracture toughness of the pressureless sintered BAS/SiC ceramics are 413 MPa, 210 GPa and 5.03 MPa•m^1/2 at room temperature.

Phase structure and thermal properties of bismaleimide/polyethersulfone multi-phase resin system

Huimin DONG, Xuefeng AN, Li YAN, Huanghai QIAN, Lijun CHENG, Liping LIU, Yueteng LI

2019, 39(3): 81-87.

[Abstract](2874) [FullText HTML] (1474) [PDF 1083KB](53)

Abstract:
The effect of micro phase morphology of bismaleimide (BMI)/polyethersulfone (PES) multi-phase system on the thermal properties was studied by SEM, DMA and TGA. The SEM results suggest that the phase separation exists in the multi-phase BMI/PES resin. Phase inversion happens with the addition of PES up to 15 phr. SEM shows that the subtle micro structure with fine BMI-rich particulate phases is surrounded by continuous PES-rich phase. The glass transition temperature (T_g) belonging to BMI-rich phase of BMI/PES resin is higher than neat BMI resin. BMI/PES-5 resin system exhibits only one T_g and the temperature corresponding to the decrease of initial modulus increased. The high-temperature plastic behavior of BMI/PES resin system is enhanced with the increase of PES. The peak thermal decomposition temperature and char yield of BMI/PES resin are enhanced owing to the excellent interface interaction between BMI and PES as well as the thermal protection effect of PES. The heat resistance of resin systems under N₂ atmosphere are superior to the systems under air atmosphere.

Hygrothermal properties of domestic T800 carbonfiber/epoxy composites

Xiaodong SUI, Shu XIONG, Liang ZHU, Ye LI, Na LI

2019, 39(3): 88-93.

[Abstract](2657) [FullText HTML] (1329) [PDF 837KB](65)

Abstract:
Scanning electron microscope (SEM) was used to study the morphologies of 3 kinds of domestic T800 carbon fiber (CCF800). Infrared spectrogram was used to analyse the structure of CCF800 sizing agent. In order to study the hygrothermal properties of domestic CCF800/epoxy composites, moisture absorption behavior and interlaminar shear property under hygrothermal environment were tested. Furthermore, SEM was used to study the interface between carbon fiber and epoxy after hygrothermal treatment. The results show that the morphologies of the 3 kinds of CCF800 are similar, while the chemical structures of sizing agent have a difference. The three kinds of CCF800/epoxy composite share the similar saturated moisture absorption period, that is about 54 days. And 95% saturated moisture absorption period is also the same, that is about 30 days. However, there is a obvious difference in saturated moisture absorption. In CCF800-3 sizing agent, the highest content of hydroxy leads to the highest moisture absorption rate of its epoxy resin matrix composite, and the interlaminar shear strength decreases most obviously under the action of high temperature and high humidity.

Novel honeycomb sandwich structure wave-absorbing composites with metamaterials

Songming LI, Sibao WU, Jiafu WANG, Haijun LU, Liying XING

2019, 39(3): 94-99.

[Abstract](2863) [FullText HTML] (1476) [PDF 1155KB](64)

Abstract:
The wide-band wave-absorbing properties of novel metamaterial honeycomb sandwich structure composites were studied, and the effects of wave-absorbing honeycomb height and dielectric property on the wave-absorbing properties of novel metamaterial honeycomb sandwich structure composites were analyzed. The results show that the wave-absorbing properties of metamaterial structures are improved while the honeycomb heights is increased. The matching effect of metamaterial structures and wave-absorbing honeycomb is improved firstly, and then decreased with the increase of the dielectric properties of wave-absorbing honeycomb. While ε′ is between 1.59-1.84 and ε″ is between 1.31-1.75, the matching effect is optimal. By the introduction of metamaterial structures, the average wave-absorbing properties at 1-2 GHz of novel metamaterial honeycomb sandwich structure composites are significantly improved, and the weight is greatly reduced.

2019 Vol. 39, No. 3