The development of next generation aero-engines requires support of advanced materials and appropriate new structures and technologies. According to the service environment of aero-materials,some points of view on combining the structure concept with material concept,the advancement and reliability of aero-engines with the controllability and safety of structure and defect for research and development of materials are proposed. From the aspects of fundamental properties of maximam service temperature,high temperature specific strength,antioxidation,toughness,conductivity and processing ability,the behaviour of traditional and new materials systems is analysed and some suggesstions aimed at the problems in development of aero-engine materials in China are presented.

The advanced polymer composites community has made great progress during the past thirty years.An assesment on the state of the art of the advanced polymer composites as well as their applications in aviation industrial is presented.The future development and research prospects of advanced polymer composites are discussed.

This paper introduced the two main electrica1 conduction mechanisms of the silicone conductive rubber,which are conductive pathway theory and quantum mechanics tunne1ing effect theory.The progress of electrical1y conductive fillers is mentioned,and the factors affecting the conductive properties of silicone rubber are discussed based on temperature,pressure,machining technics and so on.In addition,the applications and prospect of the conductive silicone rubber are briefly viewed.

A review on the 20th century development history of casting superalloys is presented.Several main events,vacuum melting,directionally solidified and single crystal superalloy,alloy design,Ni3Al-based casting alloys,numerical simulation technique and fine grain casting are described.Furthermore,some prospects on the developments of cast superalloy in the 21th century are proposed.

The basic failure modes in unidirectional composite laminates have been given and the damage characteristics in multi directional composite laminates have been summarized. In composite laminates there are four basic failure modes: matrix cracking, delamination, fiber breakage and debonding. Although numerous and complicated failure modes can be combined from the four basic failure modes mentioned above, all the failures in composite laminates can be divided into two kinds:"fiber dominated modes" and "matrix dominated modes". The failure analysis methods for composite laminates have been also discussed in this paper. At present, the knowledge of fractography of composite materials is growing and paid much attention.

The strengthening mechanisms and strength prediction have always been the focus of investigation, because these are critical to the design of metal matrix composites (MMCs). Numerous strengthening mechanism and theoretical models have been developed to correlate the mechanical behaviors of MMCs with their microstructure characteristics, but no one accords with the experimental results very well. An overview of recent studies on strengthening mechanisms and models for MMCs is presented. The disadvantages, appropriate research orientation are also discussed.

The fatigue life experiments of 7075-T651 aluminum alloy were conducted under different stress amplitude and S-N curves was gained from fitting the experimental data.An estimation of detailed fatigue limit result was 223MPa.The fractography of high stress amplitude and low stress amplitude using scanning microscope displayed that the crack initiation mostly derived from the interior flaw or inclusion,and crack propagation gone with the quasi-cleavage crack.The crack propagation regions under high stress amplitude was characterized by furrow and tyre patterns while lots of fatigue fringe together with the fatigue sidestep and secondary crack generated in the crack propagation regions of low stress amplitude.The tearing edge and equiaxial dimples existed in fatigue failure region of both high stress amplitude and low stress amplitude fracture surface.The bulky inclusion particles can be the crack initiation while dispersion of tiny precipitated phase has a positive influence on fatigue performance of 7075-T651 aluminum alloy.

The measurement principles of indentation creep by depth sensing indentation were elucidated,and recent progresses in investigation on indentation creep were also introduced.The creep behavior of metallic materials such as Ta,Ni and Ni-based alloy,BaTiO3 and Ag/Co multilayers were measured by depth sensing indentation.The stress exponents and the corresponding creep mechanism were also analyzed.

Benzocyclobutene is a thermally activated precursor to the highly reactive intermediate orthoquinodimethane. The intermediate will react either with itself or dienophile in a Diels-Alder fashion. The chemical reaction principle for benzocyclobutene compounds, the properties and applications of polymers from benzocyclobutenes are reviewed in this paper. The tendency and prospect for the development of the materials are also discussed.

The microstructures and tensile properties of cold-rolled and T3 treated 2524 aluminum alloy sheet with the thickness of 2mm at different orientation were investigated by tensile test,OM,XRD and TEM analysis.On the basis of the model that regards the sheet containing only {110}texture,the relationship of in-plane anisotropy and the anisotropy of crystallography was analyzed.The results show that the strength of 2524 cold-rolled and T3 sheet orientated 45° and 60° with respect to the rolling direction is lower than that of specimens orientated 0°,30° and 90° with respect to the rolling direction.The elongation of the sheet orientated 45° with respect to the rolling direction is highest,And then the tensile properties of the sheet orientated 0° with respect to the rolling direction are both higher than that of the sheet orientated 90° with respect to the rolling direction.The IPA of cold-rolling condition alloy sheet is higher than that of T3 condition.The major crystallographic texture of 2524 cold-rolled sheet is {110},and the secondary crystallographic texture is {311}.But the major crystallographic texture of 2524-T3 condition is {110}.The in-plane anisotropy of mechanical properties of 2524 aluminum alloy sheet is closely related to the grain structure and crystallography orientation,among them crystallographic texture is responsible for the in-plane anisotropy of mechanical properties.

Residual stresses of a very significant level were introduced when aluminum alloy parts were quenched in cold water from the temperature of solution treatment Residual stresses cause not only distortion and cracking, but also enhance susceptibility to stress corrosion cracking (SCC) and lead to premature failure The aim of this research is how to control and relieve residual stresses in high-strength aluminum alloy parts First, various quenching processes have been evaluated in an attempt to combine low residual stresses with the required levels of mechanical properties during solid solution, involving quenching into boiling water, spray quenching and polymer glycol quenchants The second part of this paper is focused on the comparison of different stress-relieving techniques, highlighting their key attributes, specific advantages and limitations Moreover, the paper concludes that all stress-relieving techniques should be carried out immediately after being quenched in the solution treatment.

P/M superalloy becomes excellent material for fabricating turbine discs used for advanced aviation enging due to its special structure and properties.To advance the applicable property and security of aviation enging,the material from melting original alloy to engineering application of turbine disc was studied,and remarkable results in aspect of so many key technologies were gained due to the result of the foundation of fabricating technique for turbine disc and the establishment of process and testing documents.Numerical simulation is widely used to fabricate P/M turbine disc for the purpose of shortening studying period and optimizing processes,and the preparatory experimental results were achieved.

A new type Korex honeycomb cell materials was introduced. Korex is an aramid/phenolic high mo dulus,high strength true composite honeycomb core. It was first introduced in 1992 in response to industry desires for a lightweight composite core with greater stiffness, strength and fatigue resistance. The mechanical properties and typical application properties for Korex honeycomb core of different cell-density have been also compared in the article. A few new type honeycomb structure have been given. The research for new type honeycomb cell structure and materials will efficiently increase the mechanical properties of honeycomb structure, decrease their structure weight and enhance their working reliability. All these are very beneficial to enlarge the application of honeycomb structure in aerospace and other industry fields.

This paper reviewed the progress of high-temperature PMR type polyimide matrix composites, and summarized its application in aeronautical engine field.

Continuous fiber reinforced silicon carbide ceramic matrix composites were developing towards possessing self-healing properties for the need of high thrust mass ratio aerospace-engine working in thermal oxidizing environment.The microstructure and properties of a self-healing silicon carbide matrix composite were introduced.The mechanism of toughness and stiffness of the composite and the self-healing behaviors were commented.The application progress of self-healing silicon carbide component was summarized.Manufacturing method and technique feature were reviewed.Multi-component and multi-layer microstructure was the key point for this composite possessing self-healing and toughing properties,and oxidation resistant system which exhausted O2 and sealed crack in each layer.This self-healing silicon carbide matrix composite coule not only meet the requirements of for aerospace-engine service but decreased weight remarkably,increased thrust-weight ratio in return.

The recent development of near net-shape investment casting technology for superalloys was introduced.The researching results of investment casting technology for superalloy turbine blades/vanes,integral turbine wheels,nozzle assembly and casings of aero engine in BIAM were mainly introduced.Meanwhile the researching scopes in the future was discussed.

Hafnium and zirconium can promote the formation of (γ+γ′) eutectic,MC(2) carbides,M2SC sulfides and Ni5M phases in superalloys,change script MC and M3B2 into blocky shape and delay the initiation and propagation of cracks by cleaning the free state sulfur at grain boundary and interdendritic regions and strengthening their cohesion.Both of elements Hf and Zr increase the stress rupture strength and ductility of cast superalloys at intermediate temperature and also improve the tensile strength and ductility at room temperature.Hf and Zr strict the precipitation of secondary carbides,such as M23C6 and M6C,therefore stabilize the microstructure of alloys during long-term exposure at elevated temperature.However,Hf and Zr lower the incipient melting temperature of superalloys.The melting of Ni5Hf or Ni5Zr phases may be considered as one of the main factors affecting incipient melting.By means of a pretreatment at 1150℃/8h,Ni5Hf phase can be eliminated in two ways: The reaction Ni5Hf+ γ(C) →MC(2)+ γ or solid solution.Hafnium may narrow down the range between temperature lost the interdendritic capillary feeding action and solidus,as well as may decrease the liquid content necessary for linking the interdendritic pools in the late solidification.The Hf-rich melts in interdendritic zone have superior fluidity,wettability and skin effect.These are the factors in increasing castability and weldability of Hf-containing superalloys and in decreasing tendency of hot tear.The high chemical activity of skin Hf-rich liquid promotes the formation of a thin layer of Hf2O on the surface of castings.Hf and Zr are the melting point depressant in the interlayer alloys used for brazing.It may be considered that dendrites formed in the early solidification are brazed by interdendritic Hfor Zr-rich melts.Eventually,the Ni-18.6Co-4.5Cr-4.7W-25.6Hf and Ni-10Co-8Cr-4W-13Zr alloys were developed according to the composition of Hf-or Zr-rich melts,and the Si-or B-free-bonding for single crystal superalloys could be realized.Studying the Hf-rich melts also leads to the development of unidirectionally solidified lamellar Ni3Al/Ni7Hf2 eutectic.The suitable compositions for these eutectic in situ composites are Ni-5.8Al-32Hf and Ni-4Al-26Hf-8Cr-4W.The results showed that the lamellar Ni3Al/Ni7Hf2 eutectic aligned parallel to the direction of solidification were prepared with temparature gradient G=250℃·cm-1 and solidification rate R=5μm·s-1 for the ternary alloy,and G=350℃·cm-1 and R=1μm·s1 for multicomponent alloy.

The cure reaction of cyanate ester resins via the auto-catalytic mechanism, or catalyzed by active-hydrogen compounds and by organic-metal complexes, as well as the different kinds of catalyst used were reviewed. The recent progress of catalyst research in photoinitiating organometallic complexes and organic tin compound is also discussed.

The current status of development of high performance aeronautical gear steel has been evaluated.Three generation gear steels,including high hardness steel used at conventional temperature,high hardness steel used at medium temperature and the steel which possesses ultra high hardness in case,ultrahigh strength with excellent toughness in core,corrosion resistance used at high temperature have been developed.It is the best way to obtain high power density and long life gear to develop higher-performance gear steel, superpure melted and advanced relative technique,such as design,manufacture,heat treatment of gear.

The TLP bonding process for DD3 superalloy using a B-contain interlayer alloy with different temperature and holdingtime is analyzed. Microstructures of different joints were observed and the widths of the eutectic zone of the centre of the joints were measured. It shows that the width is inversely proportional to the square root of holding time. Based on the result, the time for isothermalsolidification at 1150℃, 1200℃ and 1250℃ are not more than 3h, 2h and 1h respectively by the estimation. By establishing the diffusion model and using the error function solution to the second Ficks law,the time for isothermalsolidification at different temperature is calculated by NiB phasediagram and DD3B analogous phasediagram,respectively.The calculated results show that for a certain bonding system, there exists an optimum temperature at which the time for isothermal solidification is the shortest. According to the experimental results, it is suitabk to choose 1250℃ as the bonding tamperatune for DD3 superalloy.

An experimental study of stable fatigue crack propagation behavior and the measurement of fatigue crack propagation thresholds of YB-MD-3 PMMA plates was carried out at room temperature.During the preparation of initial through fatigue cracks for M(T)specimens,load cycles with compressive portion demonstrates better quality than usual tension-tension loading.The fatigue crack propagation rate in Paris's region for certain load ratio shows good correlation with a straight line in double logarithmic da/dV-ΔK coordinate.The da/dN and the slope of the straight line increases with the increase of load ratio.For the negative load ratios,however,the compressive portion in load cycles accelerates the crack growth.A proper formulation to these effects is unavailable.The fatigue crack propagation rate in YB-MD-3 plates is also sensitive to the change of load frequency at room temperature,even for very low frequencies,say,1Hz and 2Hz.

A series of polyimides had been prepared via one-step high temperature polycondensation procedure from 1,4-bis(3'-amino-5'-trifluoromethylphenoxy) biphenyl(m-TFDAB) and 3,3',4,4,'-biphenyltetracarboxylic dianhydride(s-BPDA) or 2,3,3',4'-biphenyltetracarboxylic dianhydride(a-BPDA),respectively.Two polyimides,PI-1(s-BPDA/m-TFDAB) and PI-2(a-BPDA/m-TFDAB) have been successfully prepared by one-step procedure,whose properties were widely researched.The results showed that asymmetry wouldn't greatly affect the thermal and mechanical properties of the polyimides.On the contrary,asymmetry enhanced the solubility of the polyimides in organic solvents and increased the transparency of the PI film.PI-2 was soluble not only in polar aprotic solvents,but in many common solvents.PI-2 film showed good transparency in the visible light region with transmittance of 86% at 450nm wavelength.Furthermore,PI-2 exhibited good thermal stability with the initial thermal decomposition temperature of higher than 580℃ in nitrogen and 67% of residual weight ratio at 700℃.

The thermal conductive and electrically insulating silicone rubber was prepared using the methyl vinyl silicone rubber and heat conductive hybrid alumina powder with two different particle sizes.The examinations of effects of alumina filler content on the thermal conductivity,mechanical properties,curing behavior,coefficient of thermal expansion(CTE) and heat stability of the silicone rubber indicated that the thermal conductivity and heat stability increased with increasing the filler content,while CTE and mechanical properties declined;alumina has a slight influence on the curing reaction of silicone rubber.In addition,a novel type of electrical fiberglass reinforced composite silicone rubber with thermal conductivity of 0.92 W·(m·K)-1,good electrical insulation and mechanical properties,was developed based on the alumina filled silicone rubber.The developed composite silicone rubber is a kind of ideal thermal interfacial materials for heat dissipation of higher performance devices.

The appearance of element Zr in aluminum alloys was summarized in the paper. Effects of the element on aluminium alloys such as recrystallization behaviour, quench sensitivity, aging behaviour and comprehensive properties (tensile strength, fracture toughness and stress-corrosion resistance etc.) were emphasized on. Applications of element Zr in aluminum alloys, especially in high-strength aluminum alloys were briefly introduced. Based on the new tendency of current research and development, it was pointed out that the understanding and investigation of element Zr should be made much further.

The superplastic behavior and isothermal forging technology of FGH96 alloy were investigated in this paper.The experimental results show that grain-refining treated FGH96 alloy obtained extremely significant superplasticity at temperature 1020～1100℃.When as-HIP and HIP+HIF FGH96 alloy was isothermal compressed at the same deformation condition,the flow stress of HIP+HIF FGH96 alloy was significantly reduced.The results of investigation on superplastic isothermal forging process of FGH96 alloy have made it possible to produce large disc forgings with relatively smaller equipment.

The process of the application of reaction bonded SiC ceramics to the manufacture of spacecraft combustion chamber was investigated.The results showed that spacecraft combustion chamber made from reaction bonded SiC ceramics is acceptable and results of the experiment is satisfactory.The strength of parts with reaction bonded SiC ceramics is changing with silicon content.Under the this article testing condition,the optimum silicon content is 10.5%.The method of reaction bonded SiC ceramics is suited for manufacture parts of complicated structure and higher size precision.

Three kinds of thermoplastic composites have been made with PES, PES C, PEK C and a high stress continuous glass fiber roving. The preimpregnating technology, forming process parameters were investigated. Test on their elementary mechanical properties, and the fracture appearance (SEM) of 45° longitudinal transverse shear were analysed.

P/M superalloys become first-choice material for high performance applications such as turbine disks used for high thrust-weight ratio aeroengine due to the superior high temperature porperties.In recent years,because of the in-depth research on double-properties turbine disk with duplex structure,the prospect in application of P/M superalloy will be more hopeful.The development of double-properties turbine disk applied in domestic and abroad aircraft was summarized,the encounter problems in the study were analysed with emphasis,some suggestions for improvement on double-properties turbine disk were also proposed.

The article mainly shows the properties of silicone rubber at high or low temperature.The effects of metal oxides Fe2O3,Fe2O3/SnO2,SnO2,CeO2 on the thermal stability of methyl-vinyl silicone rubber(VMQ),methyl-phenyl-vinyl silicone rubber(PVMQ),and trifluoropropyl contained silicone rubber(FVMQ) were studied by heat aging test.Through coefficient of cold-resistance under compression and DMTA,the characters in low temperature of VMQ,PVMQ and FVMQ were also studied.Result shows that metal oxides such as Fe2O3,Fe2O3/SnO2,SnO2 and CeO2 can greatly improve the thermal stability of silicon rubber.The analysis of x-ray photoelectron spectroscopy(XPS) showed that Sn+4 were reduced to Sn0 in silicone rubber during thermal air aging.The thermal stability of silicone rubber could be improved by some metal oxide.The results of DMTA showed that the rubber based on PVMQ,SKTFT-50,SKTFT-25 and the copolymer have excellent cold resistance.

The recent advancement of the oxidation protective coatings of C/C composites in China was reviewed.New technologies and new improvements of the traditional coating preparation technologies for C/C composites were introduced.According to the application conditions of C/C composites,the development trend of anti-oxidation coatings was also proposed.It was showed that the present research results could not meet the requirements of the coated C/C composites in severe work environments.The further researches would be focused on the preparation of suitable coating that could protect C/C composites from oxidation from room temperature to 1700℃ in high speed gas-fired environments.To reduce the cost of preparation,the coating that could works at 1800℃ for long time should be exploited.

The corrosion and protection for aeronautical materials in China is reviewed.The techniques and research in natural environmental test,indoor accelerated tests,corrosion mechanics and tests,high temperature protective caotings,surface treatment and protective techniques are introduced.The development trend and application prospect of corrosion and protection are proposed.

Effect of solution treatment on mechanical properties and microstructure of Al-Cu-Mg alloy with Ag addition was studied by using optical microscopy（OM），scanning electron microscopy（SEM），transmission electron microscopy（TEM），differential scanning calorimeter （DSC），and tensile test. Results show that the most suitable solution treatment process of the alloy is solutionizing at 515℃ for 1.5 h. After aging treatment at 185℃ for 4 h，tensile strength and elongation of the alloy are 503 MPa and 12.3%， respectively. The mechanical properties of the alloy increase first with increasing solution temperature and time，then decrease with solution temperature over 515℃（holding time is 2h）or solution time（solution temperature is 515℃ ） longer than 1.5 h. The lower solution temperature and less solution time result in a less resolution of excess phases and produce a lower strength of the alloy. However，too high solution temperature and excessive solution time easily lead to overburn of the specimens. The overburned temperature of the alloy is demonstrated at 525.9℃. The solution temperature has stronger influence on mechanical properties and microstructure of this alloy than the solution time.

Based on the data of hotcompressing tests which were carried out at temperature ranged from 1050℃ to 1110℃ and strain rate from 0.01s-1 to 1s-1, a system of flow curves of the new type 3rd generation nickelbased superalloy FGH98 was obtained .Then they were used to uncover how the flow stress changes by the change of temperature and strain rate as well as strain.It shows that the curve takes on a typical agitation charateristic and the flow stresses are very sensitive to temperature and strain rate.Subsequently, Arrehenius equation was selected as a model of the constitutive relationship, and the relative parameters were figured out by linear regression analysis of the experimental data with simple error analysis.Then the constitutive equation has been established.

利用带有加热装置和同步组装系统的高温Hopkinson压杆系统对某不锈钢材料在温度20~800℃时，应变率103~104s-1下的动态压缩力学性能进行了测试，得到了材料在不同温度和应变率耦合作用下的真实应力应变曲线。对比准静态结果，考察了材料流动应力的温度和应变率敏感性，并根据热激活位错运动理论对其内在机理进行了解释和探讨。试验表明，材料具有显著的热软化和应变率强化效应；且高温时，材料的温度敏感性、应变率敏感性均显著增加。

In order to improve the mechanical properties of cyanate ester resin,Bisphenol-A dicyanate(BADCy) was copolymerized with E20 and E51,respectively.DSC and FTIR studies showed that both E20 and E51 epoxies were catalytic for the curing reaction of BADCy while E20 epoxy had stronger catalytic effect than E51.By means of SEM,large amount of tough whorls and break were observed in the fractures of BADCy modified by E20 and E51.It turns out that heat deflection temperature(HDT) and moisture absorption of the modified systems decreased with the increasing of epoxy content and E51 epoxy modified BADCy system displayed relatively higher HDT and lower moisture absorption than that of E20 epoxy modified one.

The film thickness uniformity is an important reflection of the film quality and the device performance.The influence of the target substrate distance,sputtering power and working pressure on the film thickness uniformity deposited by self-designed magnetron sputtering deposition equipment has been studied.The film thickness measured by SENTECH Instruments GmbH's Spectroscopic Ellipsometry SE800.The result indicates that,the film has a good uniformity at a long target substrate distance.The sputtering power and working pressure also have influence on the film thickness uniformity.

Work hardening rate curve under the large strain and inflection point criterion of dynamic recrystallization from the curve for determining critical strain theory was analyzed based on dislocation. The dynamic recrystallization critical conditions for onset of DRX during β process were established according to the work hardening rate approach,using experimental data obtained during compression deformation in the range of deformation temperature 1050～1100℃ and strain rate 0.001~1s-1.Furthermore,the predicting model of critical strain was determined by the Zener-Hollomon parameter approach. The results indicate that two type of stress-strain curve is observed under present deformation conditions.The critical conditions leads to the appearance of an inflection point in the θ-σ curve and to a minimum value of -∂θ/∂σ when the critical state is attained. There are linear relation between critical strain and peak strain,i.e. εc/εp=0.62.The predicting model of critical strain were established by the function of εc=1.7210-2Z0.0605

Vibration damping is very important to improve dynamic behavior of composite structures There is a strong need for information on damping research in design optimization of composite structures In this paper,the status of research on damping in fiber reinforced composite materials and structure has been reviewed The content can be divided into three parts,such as damping mechanisms,modeling of damping and enhancement of damping At last,the recommendations regarding future research have also been offered.

High temperature accelerated aging was adopted to investigate property changes and life-span of sulfured nitrile-butadiene rubber(NBR) in glycol.Mass loss,mechanical property change,cross-section morphography of sulfured NBR aging in glycol at 70℃,90℃,110℃ were studied.According to Arrhenius equation,regard elongation as criterion,the relationship of velocity constant of aging and temperature was deduced.All results show that substance exchange exists between sulfured NBR and glycol,while sulfured NBR loses weight,sulfured NBR becomes brittle in glycol,holes and flaws also develop,life-span of sulfured NBR in glycol at a certain temperature could be deduced by high temperature accelerated aging.

The interface between the matrix and reinforcement plays a crucial role in determining the properties of metal matrix composites (MMC).Surface treatments and coating of the reinforcement are some of the important techniques by which the interfacial properties can be improved . Reinforcement coatings are classified as metallic,ceramic,bilayer and multilayer coatings. Fabrication methods often include electroless plating ,chemical vapor deposition,and sol gel technique, etc. Coatings on three important reinforcements, such as carbon, silicon carbide (SiC) and alumina (Al2O3) and their effects on the interface and properties of aluminium alloy matrix composites are reviewed.