航空材料学报

Effect of Fine Grain Treatment on Mechanical Properties of Micro-Alloyed GH761 Alloy

YANG Shu-lin, SUN Wen-ru, GUO Shou-ren, WEI Zhi-gang, YANG Hong-cai, HU Zhuang-qi

2006, 26(4): 1-5.

[Abstract](1390) [PDF 907KB](202)

Abstract:
Six methods of heat treatment were adopted to gain a fine grain structure of GH761 alloy,which was micro-alloyed by adding 0.023% phosphorus.When the temperature of the given primary treatment changed within 780~950℃,no obvious effect on the grain microstructure of the alloy was observed.Compared with that of commercial GH761 alloy treated by the standard treatment,the grains of the test alloy became much finer.The higher mechanical properties were obtained when the alloy was treated at 830 ℃ for 4h,AC,and 720℃ for 24h,AC.The tensile strength at room temperature and 650℃ was enhanced significantly,compared with that of standard treated GH761 alloy.The reduction of area was improved remarkably and elongation was also elevated a little.The stress rupture life of the alloy at 650℃ and 690 MPa was even longer than that of the commercial GH761 alloy at 650℃ and 637 MPa.

Low-Cycle Fatigue Life Prediction of Single Crystal Nickel-Based Superalloys under Asymmetrical Cyclic Loading

DING Zhi-ping, CHEN Ji-ping, YIN Ze-yong, YANG Zhi-guo

2006, 26(4): 6-10.

[Abstract](1571) [PDF 252KB](261)

Abstract:
Low cycle fatigue experiments of DD3 single crystal superalloys along,and orientations under asymmetrical cyclic loading at 680℃ showed that crystal orientation affected low cycle fatigue life of DD3 single crystal superalloy significantly,life along orientation was the longest,life along orientation was the shortest.By modifying strain range with orientation function,the effect to fatigue life from orientation could be eliminated.A parameter k was introduced to express the effect that characteristic of cyclic loading affected fatigue life,and relationship between cyclic life and k indicated power law.According to main factors of affecting low cycle fatigue life for gas turbine blade of single crystal nickel-based superalloy,the formula of cyclic plasticity strain energy was put forward.The main factors of constructing cyclic plasticity strain energy should include total strain range,orientation function and characteristic of cyclic loading,and relations between those parameters and cyclic plasticity strain energy were power law curve.Low cycle fatigue life model for single crystal superalloy was deduced by using cyclic plasticity strain energy as a parameter,and the coefficients that appear in the model could be obtained from fitting fatigue tests data by multianalysis of linear regression,the all data fell into the factor of 2.6 scatter band.

Influences of C and Mg on Microstructures and Mechanical Properties of a Nickel Base Superalloy

YU Qian

2006, 26(4): 11-13.

[Abstract](1494) [PDF 287KB](195)

Abstract:
The influences of C and Mg on microstructures and mechanical properties of a nickel base superalloy were studied.The results showed that when C content was low,the amounts of carbides in the alloy was little and distribution of carbides was not uniform,therefore the stressrupture life was reduced;With the increasing of C content,the distribution of carbides became more uniform,so the stress-rupture life was increased.No obvious effects were found on the microstructures and mechanical properties of the alloy when Mg content was low.The carbides in grain-boundary became bigger when Mg content was high,therefore,the impac value and tensile plasticity were reduced.The carbides were fined with granular in grain-boundary with appropriate content of Mg,impact value and tensile elongation were increased obviously.

Effect of Long Term Ageing on Microstructure and Mechanical Properties of Low Expansion Superalloy GH783

JIA Xin-yun, ZHAO Yu-xin

2006, 26(4): 14-17.

[Abstract](1473) [PDF 837KB](214)

Abstract:
The effects of long term ageing to 1000h on microstructure and mechanical properties of superalloy GH783 at 750℃ were studied by testing mechanical properties and examing microstructure using optics microscope and SEM.The results showed that the size of γ′ phase and the amount of β phase increase,strength and stress-rupture life decrease with ageing time increaseing,but there are higher ductility.

Effect of Surface Topography on Micro-Mechanical Behavior for Different Metallic Materials

MENG Bo, GUO Wan-lin, JIANG Yan

2006, 26(4): 18-23.

[Abstract](1385) [PDF 689KB](327)

Abstract:
Surface topographies of different machined specimens from three typical metallic materials,stainless steel,Ti alloy and Al alloy,have been quantitatively characterized and analyzed to investigate the effect of surface topography on micro-stress concentrations based on the atomic force microscope measurement and finite element simulation.It is found that the surface topography is significantly influenced by the surface treatment method.However,the surface characteristic parameters have shown different variation rules for different metals.It is not only the surface roughness parameters but all characteristic parameters that determine the micro-stress concentrations caused by the surface conditions.Therefore,the integrated influences of surface characteristic parameters on micro-stress behaviors should be considered to estimate the effect of surface conditions on material fatigue performance effectively.

Microstructure and Mechanical Properties of Stainless Steel Wires Used for Metal Rubber

KOU Hong-ning, LIU Guo-quan, YANG Jian-chun, BAI Hong-bai

2006, 26(4): 24-28.

[Abstract](1507) [PDF 568KB](387)

Abstract:
The microstructure and mechanical properties of stainless steel wires used for metal rubber were studied by means of optical microscopy,SEM,and X-ray diffraction.The wire diameters were 0.4,0.3,0.2,and 0.15mm,which were obtained by cold drawn of 36%,64%,84% and 91%,respectively.The deformation-induced martensite content in the wires increased with the deformation,starting from 81.2% at 36% deformation.The microstructures of metal rubber produced using these wires should mainly consist of martensite other than austenite,although the experimental material is a typical austenitic stainless steel.SEM observations showed that there were large quantities of voids parallel to the drawing direction,whose volume fractions increased with the deformation.Meanwhile,the tensile strengths of the wires were 1406~2244MPa, the elongations were 13.0%~8.9%.Therefore,we can conclude that the metal rubber produced by such wires should mainly consist of martensite and bear both micro-and macro-voids or porosities.

Application of the Orthogonal Design of Experiment on the Study of Heat Treatment for Precipitation Hardening Stainless Steel

JIN Jian-jun, GU Li-xin

2006, 26(4): 29-34.

[Abstract](1377) [PDF 304KB](171)

Abstract:
The effects of prime heat treatment parameters on mechanical properties of the precipitation hardening stainless steel 0Cr17Ni5Mo3 were studied by the orthogonal design of experiment.Those parameters are solution temperature,solution time,equalization temperature,equalization time.The results show that a lot of experiments in finding out the relationship between heat treatment parameter and mechanical property by using the orthogonal design of experiment for the precipitation hardening stainless steel could be saved.

Research on Gamma TiAl-Based Alloy Sheet Fabricated by EB-PVD

ZHANG De-ming, CHEN Gui-qing, HAN Jie-cai, YAO Zhen-zhong

2006, 26(4): 35-38.

[Abstract](1479) [PDF 573KB](341)

Abstract:
Gamma TiAl-based alloy sheet with 150mm×100mm×0.4mm was fabricated successfully by EB-PVD process,a new technique for producing sheet.The phase composition and micrographs of fractures of the deposited and annealed samples were analyzed by SEM and XRD.The results indicated that the deposited γ-TiAl based alloy sheet was composed of γ,α2 and τ phase,and the quality of the surface was well.There was spontaneous lamination inside the sheet and the microstructure was columnar crystal,which transformed into equiaxed crystal with τ phase disappeared,α2 phase decreased obviously,and the lamination trended to eliminate after vacuum heat treatment at 1000℃/16h.The fracture of the material was diverted from the manner of intergranular brittle fracture to the manner of intergranular brittle fracture with dimple gliding fracture.

Influence of Elastic Modulus of Adhesive on the Stress and Strain Distribution in Aluminium Single Lap Joint

YAN Zhan-mou, YOU Min, YU Hai-zhou, GONG Zheng-peng

2006, 26(4): 39-42.

[Abstract](1442) [PDF 517KB](460)

Abstract:
The elasto-plastic finite element method(FEM) was used to investigate the effect of the elastic modulus of adhesive on the stress and strain distribution in adhesively bonded aluminium single lap joint.The results from the numerical simulation showed that the value of peak stress became higher as the elastic modulus of adhesive increased and the peak stress transferred from the adhesive layer to the fillet.It was also shown that the larger the stiffness,the smaller the strain.For the aluminium single lap joint bonded with low elastic modulus adhesive,the load was mainly undertaken by the adhesive layer and the stress distributed more uniformly in it and a little load born by the fillet.In other words,the adhesive fillets didn’t play the pole of decrease the peak stress of adhesive layer evidently.For the aluminium single lap joint bonded with high elastic modulus adhesive,the function of adhesive fillets was very large so that a lot of load was undertaken by it but the stress and strain distributed in the middle layer of the adhesive was not uniformly as that in the one bonded with low elastic modulus adhesive.

Study on Pouring System Design Method of Large Dementional Complicate Aluminium Precision Castings with Barrel Structure

HONG Run-zhou, ZHOU Yong-jiang, YAO Wei-bin

2006, 26(4): 43-45.

[Abstract](1507) [PDF 201KB](301)

Abstract:
The pouring system design method of large dimention,intricate aluminium alloy precision castings with barrel structure was studied.Based on the pouring system design and pouring experiments of three kinds of large demention,intricate aluminium alloy precision castings with barrel structure,these castings were carried out with qualified metallurgical quantity and mechanical properties.The results of these experiments show that in the condition of anti-gravity casting,lap gating system or lap gating combined with bottom gating system is a more practical pouring system for these castings.

Mechanism Analysis on Reducing Pressure of Tube Hydroforming through Preform

YUAN Shi-jian, LIU Gang, HAN Cong

2006, 26(4): 46-50.

[Abstract](1491) [PDF 481KB](408)

Abstract:
Pressure for tube hydroforming of lightweight parts is usually determined by the radii of bulgy corners because the pressure for forming a small corner is much higher than other positions.Therefore,it is a key problem how to reduce the pressure for forming the corner with a small radius in tube hydroforming.Stress distribution and deformation mechanism of the corner on a hollow component during hydroforming is analyzed by classical mechanics and finite element method.For tube hydroforming of hollow component with polygonal sections,a rectangular cross-section is regarded as an example and researched.A method to reduce the pressure through preforming a petal-like cross-section is presented and its mechanism is analyzed.A calculated equation of key parameters of the preforming contour is given and an experiment is carried out to verify the method.The theory is meaningful for hydroforming of tubular parts with bulgy small-radius corners under lower pressure.

Effects of Technological Parameters of Impact Pressure Diffusion Bonding on Joint Strength of Titanium Alloy/Stainless Steel

YUAN Xin-jian, SHENG Guang-min, QIN Bin, ZHOU Bo, HUANG Jia-wei, HUANG Wen-zhan, LI Cong, QIU Shao-yu

2006, 26(4): 51-55.

[Abstract](1462) [PDF 969KB](319)

Abstract:
The titanium alloy TA17 and stainless steel 0Cr18Ni9Ti were bonded by using impact pressure diffusion bonding(IPDB).The tensile strength was tested by using the hydraumatic universal testing machine.Effects of the technique parameters of IPDB on the joint strength were investigated.The results show that: at the bonding temperature of 1098K,the minimum impact pressure of 8 MPa,the maximum impact pressure of 50 MPa,the cyclic number of 20,the impact rate of 0.5 Hz,the heating velocity of 30K/s and the cooling velocity of 5 K/s,the high tensile strength of the joint is 293 MPa and the bonding time is only 220 seconds,thus the high efficiency and high strength bonding of the titanium alloy and stainless steel were realized.The phase and fracture characteristics were analyzed by X-ray diffraction and scanning electron microscopy.It is revealed that the formation of β-Ti,Fe2Ti and FeTi in the interface of the titanium alloy-stainless steel joint.β-Ti Solid solution undertakes major part of tensile load in the tensile testing.

Corrosion of 316 Stainless Steel/WC-Co Coating in Liquid Zinc

WANG Wen-jun, LIN Jun-pin, WANG Yan-li, LIN Zhi, CHEN Guo-liang

2006, 26(4): 56-60.

[Abstract](1415) [PDF 1302KB](587)

Abstract:
The microstructure and corrosion behaviours of 316 stainless steel/WC-Co coating by high velocity oxy-fuel(HVOF) in liquid zinc which contained small amount of aluminium(less than 0.2 wt%)were studied.Experiment results showed that cracks appeared in coating because that residual stress built up during thermal spraying caused by improper spraying conditions and liquid zinc acted on the defects in coating.We observed that not only zinc but also chromium and aluminium diffusion into the WC-Co coating along the cracks.At the beginning of corrosion,chromium and aluminium preferential diffused into WC-Co coating.Increasing density of coating by improving technique of HVOF,the liquid zinc corrosion resistance of WC-Co coating could be enhanced.

Phase Transformation Behavior of TiNi Based Shape Memory Alloy Films

WANG Zhi-guo, ZU Xiao-tao, FENG Xiangdong, YU Hua-jun, FU Yong-qing

2006, 26(4): 61-64.

[Abstract](1493) [PDF 189KB](260)

Abstract:
In this work,TiNi and TiNiCu shape memory alloy films on Si and SiO2 substrate were successfully prepared by co-sputtering of TiNi target with a separated Cu and Ti target.The transformation behavior and stress as a function of temperature were investigated by differential scanning calorimeter(DSC) and curvature measurement methods.The results showed that the shape memory alloy film has a good shape memory effect,which was a promising candidate material for micro-electric mechanical system.For TiNi shape memory alloy film,two-stage transformation was observed,corresponding to transformations among austensite,R-phase and martensite phase.However,austensite transforms into martensite directly for TiNiCu film.The substrate and the composition of the film had a prominent effect on the transformation temperatures.The film had a good adherence on the Si substrate and is easy peeled from the SiO2 substrate.

Phase Composition and Coefficient of Thermal Expansion of Mo-Si Composites Prepared by Liquid Reactive Sintering

XIAO Lai-rong, CAI Zhi-gang, YI Dan-qing, LIU Rui

2006, 26(4): 65-69.

[Abstract](1527) [PDF 770KB](236)

Abstract:
The composites of different Mo/Si ratio were prepared by vacuum liquid reactive sintering.The phase composition and microstructure of composites was analyzed by XRD and SEM,respectively.Their coefficients of thermal expansion(CTE) were measured by thermal dilatometer.MoSi2 was primary phase in the composites.There was a little Mo5Si3 phase in the composite when Si/Mo ratio was 2.2:1.With Si/Mo ratio increase to 2.3:1 Mo5Si3 phase disappeared.The CTE increased with content of Mo5Si3 phase decreasing and reached maximum value(8.16×10-6K-1).

Study on the Microstructure of an Al-Si Coating on a Nickel-Base Superalloy K4104

NIU Jing, ZHANG Li-wen, PEI Ji-bin, ZHANG Fan-yun, LI Chen-hui

2006, 26(4): 70-73.

[Abstract](1507) [PDF 822KB](285)

Abstract:
An Al-Si diffusing coating was prepared on a nickel-base superalloy K4104 by slurry aluminizing.The microstructure of aluminization was analyzed by means of SEM,XRD,EPMA.The results showed that the phases of surface layer consisted of Al-rich β-NiAl+CrxSiy,transition layer Ni-rich β-NiAl,inner diffusion layers β-NiAl+Cr-rich phase+Ni3Al,respectively.

Study on Mechanism of the Contact Corrosion between Aluminum Alloy and Antiaging Coatings of the Rubber Fuel Tank

LI Bin, TAO Chun-hu, LI Di, WU Xue-ren, LU Feng, CAI Jian-ping

2006, 26(4): 74-79.

[Abstract](1417) [PDF 1350KB](181)

Abstract:
The contact corrosion mechanism between 7A04-T6 aluminum alloy and three antiaging coatings of the rubber fuel tank was studied.The corrosion morphology,constituents and their content in corrosion product of clad 7A04-T6 alloy and 7A04-T6 alloy were analyzed by SEM and EDS after contact corrosion happened in high temperature and high humidity environment.Results demonstrated that corrosion morphology were piting,localized corrosion or corrosion product layer.The main elements in corrosion product of clad 7A04-T6 alloy and 7A04-T6 alloy were Al,C,O,Mg,Zn,Cl,Si,S.The process and mechanism of contact corrosion between aluminum alloy and antiaging coatings were conceived as: contact-diffusion-adsorption/formation of facilitates and thin electrolyte layer/occlusive corrosion region/anion accelerates the self-catalysis corrosion/pitting-intergranular corrosion-exfoliation corrosion.

Design and Reflectivity Analysis of a Kind of Radar Absorbing Materials with Periodical Structures

CHENG Hai-feng, LIU Hai-tao, CHU Zeng-yong, ZHOU Yong-jiang, TANG Geng-ping

2006, 26(4): 80-83.

[Abstract](1514) [PDF 740KB](266)

Abstract:
The different periodical structures were designed using two different radar absorbing materials whose volume ratio was 1:1,and their reflectivities were calculated by the finite element software.The calculation results show that the absorbing peaks of the periodical structures locate between those of the two original absorbing materials,and the sizes and patterns of the periodical structures,as well as the position of the radar absorbing materials,all have influences on the radar absorbing properties to some extent.

Diffusion Welding of SiC_p/2014Al Aluminum Matrix Composite Using Ni as Interlayer

FENG Tao, WU Lu-hai, LOU Song-nian

2006, 26(4): 84-87.

[Abstract](1497) [PDF 386KB](225)

Abstract:
SiCp/2014Al aluminum matrix composite was welded by vacuum diffusion welding technique using Ni as the interlayer metal.The welding joint was analyzed by means of optical microscope(OP),scanning electron microscopy(SEM),and electron probe microanalyser(EPMA).The analysis results indicated that Ni and Al were inter-diffused and there were intermetallic compounds formed in the inter transition layer,which was composed by Ni3Al//NiAl//NiAl3.The relation between the Ni,Al diffusion concentration and the welding temperature and the keeping time was calculated.The parabolic relationship between the diffusion distance and the welding parameters was found.

Bending Property and Fracture Mechanism of Quasi-3D C/C Composites

XIONG Xiang, HUANG Bai-yun, LI Jiang-hong, WU Feng-qiu

2006, 26(4): 88-91.

[Abstract](1400) [PDF 614KB](280)

Abstract:
Using needled-carbon fiber felts as perform,quasi-3D C/C composites with pyrolytic carbon(PyC),or/and resin carbon,pitch carbon as matrix,respectively,were fabricated by chemical vapor infiltration method or/and liquid method.In the present paper,the bending property and fracture mechanism of these composites were investigated.The results showed that,the bending strength of the C/C composites with smooth laminar(SL) structural PyC matrix is obviously higher than those with rough laminar(RL) or SL+RL PyC matrix;the bending strength increase with the increasing of density of C/C composites;the higher the densification,the stronger the matrix reinforcement and the bending property.

Superplasticity of SiC/Ni Composite

ZHANG Kai-feng, WANG Chang-li

2006, 26(4): 92-95.

[Abstract](1382) [PDF 1028KB](211)

Abstract:
Low temperature superplastic tensile tests were carried out in electrodeposited SiC/Ni composite with an average grain size of 200 nm.The results showed that the maximum elongation of 571.2% was obtained at temperature of 430℃ and strain rate of 8.33×10-4s-1,where the strain rate sensitivity was 0.32.Observation of fracture surfaces and the deformed microstructure showed that the fracture mode of the material was intercrystalline fracture,and grain grew to different extent and elongated along the tensile axis.Different grain growth rates resulted in final structure made of large and small grains.Stress-strain curves indicated that stress increased to peak values then decreased.Large deformation realized in the quasi-steady flow stage after peak stress.The addition of SiC has a positive effect on the thermal stability of matrix structure,thus has a favorable effect on the superplasticity.The deformation mechanisms were grain boundary sliding and dislocation plasticity.

Fabrication and Characterization of Mono-dispersed Al₂O₃ Powders

ZHANG Gui-fang, SHEN Qiang, ZHANG Lian-meng

2006, 26(4): 96-99.

[Abstract](1399) [PDF 786KB](448)

Abstract:
Alumina precursors were synthesized from Al2(SO4)3×18H2O and CO(NH2)2 by homogeneous precipitation method.Then,fine α-Al2O3 powders with superior characteristics were fabricated from alumina precursors.Effects of reaction temperature and adding dispersants ratio on particle size,distribution of particle size,as well as morphology of Al2O3 powders,were systematically studied.This study provides theoretical basis for preparing monodispersed Al2O3 powders.The results show that,on the optimum experimental condition,the approximately monodispersed spherical Al2O3 powders,with small particle size(D1/2=1.60mm),narrow particle size distribution range(σ=0.93μm),and without obvious agglomeration, were obtained.Such fine Al2O3 powders can be used as raw materials for fabricating Al2O3 ceramic with superior properties.

Studies on Epoxies Resins Modified Cyanater

ZHANG Zeng-ping, LIANG Guo-zheng, REN Peng-gang, LU Ting-li, WANG Jie-liang

2006, 26(4): 100-104.

[Abstract](1518) [PDF 379KB](719)

Abstract:
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.

Oxidation Kinetics of in Situ Synthesized TiC/Ti Matrix Composites at Elevated Temperature

QIN Ye-xia, ZHU Jian-yong, LU Wei-jie, XU Dong, QIN Ji-ning, ZHANG Di

2006, 26(4): 105-109.

[Abstract](1449) [PDF 642KB](247)

Abstract:
The isothermal oxidation behavior of TiC/Ti Matrix Composites(TMCs) at 550℃,600℃ and 650℃ in air was investigated.The reaction products of the oxidation scale were examined by XRD.The surface morphology and cross-section microstructure of the oxidation scale were analyzed by SEM.An oxidation scale was mainly consisted of rutile-TiO2.The addition of TiC can improve the oxidation resistance of TMCs.Moreover,the increase percentage of TiC reinforcements can decrease the overall oxidation rate of TMCs at 550,600,and 650℃.It is attributed to the formation of thin and dense oxidation.The isothermal oxidation kinetic curves mainly follow parabolic rate law.

Effect of Mechanical Parameters of Adhesive on Stress Distribution of Adhesive Bonded Joints under Cleavage Loading

KONG Fan-rong, YOU Min, ZHENG Xiao-ling, YANG Chun-mei

2006, 26(4): 110-114.

[Abstract](1488) [PDF 409KB](339)

Abstract:
The stress distribution of adhesively-bonded metal/metal single lap joints under cleavage loading is analyzed using three-dimensional finite element method(FEM).The influence of mechanical parameters of adhesive on the stress distribution of cleavage joints is discussed in detail.It is shown that adhesive has great influence on the stress distribution of the lap region.Increasing elastic modulus or Poisson’s ratio of adhesive also can cause the stress concentration at the left end of the adhesive layer.With the increment of elastic modulus or Poisson’s ratio of adhesive,peak values of stresses distribution increase and stresses concentration at left end of adhesive layer become obviously higher.However,observations having been made in particular on normal and shear stress components at the interfaces,which provide useful insight into the 3D nature of the problem,indicate that the influence of Poisson’s ratio of adhesive is less than that of elastic modulus on stress distribution of adhesive layer.

Experimental Characterization of Porosity and Interlaminar Shear Strength in Polymeric Matrix Composites

LIU Ling, ZHANG Bo-ming, WANG Dian-fu, WU Zhan-jun

2006, 26(4): 115-118.

[Abstract](1663) [PDF 402KB](548)

Abstract:
A quantitative relationship between void content and interlaminar shear strength(ILSS) has been determined for a polymeric matrix composite material.Differences in void content were achieved using different pressures during the autoclave curing cycle following standard processes.Areas of different porosity were identified after an ultrasonic double-through-transmission technique.Specimens were then selected and prepared for void content measurement and for three-point flexure test.The testing results were correlated to void volume fraction and ultrasonic absorption coefficient.The study indicates that,in the range from zero to 4%,each 1% increase in porosity will cause an approximate 8% in ILSS for this polymeric matrix composite material.

Surface Analysis of High Property Carbon Fibers and Study on Mechanical Properties

WANG Xiao-jie, LIANG Guo-zheng, ZHANG Wei, YIU Li-hong, XIE Qun-wei

2006, 26(4): 119-122.

[Abstract](1375) [PDF 732KB](384)

Abstract:
The characterization on the surface of carbon fiber(T700\T800-6K\T800-12K\T1000) and the bonded interface of fiber/epoxy are analyzed by SEM,IR,XPS.The mechanical properties of Φ150mm pressure vessels are measured.The results show the surfaces of T700\T1000 are glossier,the surface of T800 has obvious groove,the surface of T1000 appeared groove after experience.XPS result shows that T700\T1000 have more active groups and T800 has less.The transfer rate of fiber strength with T700\T800-6k\T800-12k\T1000 in Φ150mm pressure vessel is 89.7%,79.2%,79.1%,93.1% respectively.Surface state of fiber has certain effect on its wetting which is one of key factor to improve the strength of composite.

2006 Vol. 26, No. 4