航空材料学报

THE EFfECT OF TUNGSTEN ON SOLID SOLUTION STRENGTHENING FOR DIRECTIONALLY SOLIDTFIED (DS) NICKEL-BASE SUPERAALLOYS

Sun Chuan-qi, Li Qi-juan, Lin Shu-xi, Wu Chang-xing, Yao De-liang

1988, 8(1): 1-8.

[Abstract](1543) [PDF 4413KB](81)

Abstract:
The effect of tungsten on creep property for DS nickel-base superalloys,DZ17G(0%W)，DZ17GW(3.8%W) and DZ3 (5.4%W) has been investigated.It has been found that the effect of directional solidification on incrcasin; the creep property is little for nickel-base superalloys containing a small amount of W or wiihowt W, Converscly,the use of DS is benifial fo[superalloy containing higher content of W, Durins steady state creep，the effective stress acting directly on the dislocations can be defined as the difference between the stress applied to the sample and the back stress resulting from the presence of all other dislocation(s-solid solution strengthening)and. of' particles(Psecond phase pa rticle strengthening) in the matrix.The back stress was calculated by the measuring of steady start creep rate.It was indicated chat the aP of three DS superalloys is almo引equivalent.The stress rupture property is much higher for DZ17GW than that of DZ17G.The creep property is best for DZ3 coniaining higher content of W. It was de nonsiratecl that the role of W in DS superalloys is mainly increasing strength of solid solution marix. The tungsten must be considered in the desinn of DS superalloy.

STUDY OF BONDING PROPERTIES OF EPOXY SYSTEMS TOUGHENED BY CARBOXYL TERMINATED BUTADINE-ACRYLONITRILE RUBBERS WITH DIFFERENT ACRYLONITRILE CONTENTS

Liu Qing-fang, Liu Zhen-hang, Zheng Rui-qi, Fan Tang

1988, 8(1): 9-16.

[Abstract](1573) [PDF 5797KB](76)

Abstract:
The effect of acrylonitrile (AN)content in liquid carboxyl terminated butadine-acrylonitrile rubber (CTBN) on the bonding properties of CTBN modified epoxy adhesive was apparent, This paper presented an investigation about such effect in the case of intermediate temperature(120℃ )curing adhesive with modified dicyandiamide system as curing agent, By means of light microscopic observation of heat curing process and scaning eletron microscopic observationof lap shear fracture surface of CTBN modified epoxy system, the reason that results in such effect was examined.

OPTIMIZATION OF SPRAYI NG PARAMETERS FOR VACUUM PLASMA SPRAYED TITANIUM COATI NGS

Lu Pan-jin

1988, 8(1): 17-23.

[Abstract](1570) [PDF 3626KB](80)

Abstract:
Vacuum plasma-spraying is a process available for producing dense and adhesive coatings of the reactive titanium, which may spread its range of application, The quality of VPS-coatings is largely depending on the proper optimizetion of spraying parameters.This paper shows that by means of the factorial analysis method, the test matrix es L16(215) and L8(27)，the porosity of VPS-Ti-coatings is successfully minimized, making high quality coatings of approx.1. 3% porossity possible.With optimized spraying parameters，good corrosion resistance, high adherence and ductility of Ti-coatings were achieved.

TTT CURE DIAGRAM AND EMPIRICAL T_g-Tcure-Time EQUATION OF CURE OF AG-80/DDS EPOXY RESIN SYSTEM

Gao Jia-wu, Shen Kui

1988, 8(1): 24-30.

[Abstract](1655) [PDF 3966KB](80)

Abstract:
The Curing behaviour of tetraglycidy 14，4'-diaminodiphcnyl methane(AG 80) epoxy resins with diaminodiphenyl Sulfone(DDS) has been investigated by torsional braid analysis(TBN)。A time-temperature-iransformation(TTT) cure diagram and an empirical Tg-Tcure-Time(TTT) eqttation,which nlay be used to provide the reference data for the curing technology of the composite of this system，have been obtained.

THE HIGH TEMPERATURE LCF BEHAVIORS OF SUPERALLOY GH169

Xie Ji-zhou

1988, 8(1): 31-38.

[Abstract](1502) [PDF 3693KB](106)

Abstract:
In this paper, the low cycle fatigue (LCE)behaviors of Ni-base supcrallcy GH169 were studied in detail at 360,550 and 650℃，including the cyclic stress strain behavior，Massing effect and the effect of temperature on LCP properties of alloy GH169. In addition, the LCE lives expressed by plastic strain energs w were also discussed.

A STUDY ON MECHANICAL PROPERTIES OF BASKET-WEAVE STRUCTURE IN TITANIUM ALLOY TC6

Wang Qing-ru

1988, 8(1): 39-47.

[Abstract](1866) [PDF 5283KB](93)

Abstract:
The relationship between mechanical properly and the thickness of alpha plate (value b) of basket-weave structure in titanium alloy TC6 was investigated.After isothermal annealing, tensile strength, fatigue strength and impact toughness of alloy TC6 are linear with LOG b, and the relating of tensile ductility to value b shows the peak behavior in this alloy, and their corresponding regression equations have been obtained.A certain correlation between creep behavior and value b also exists in this alloy.Therefore，the mechanical properties of alloy TC6 can be improved controling thickness of alpha plate of microstructure.The relationship between tensile strength and ductility of basket-weave structurcs with various amount of hot deformation of TC6 has been studied.Their corresponding linear regression equations heve been obtained.The confidence interval of confidence level a 95 percent has been given，which may be referenced for working out production technology and material specification.In addition，the relationship between fracture toughness and tensile strength of basketweave structure of TC6 was investigated.

A TEM AND HREM STUDY OF THE PRECIPITATF PHASES IN A1-Cu-Mg ALLOY

Jin Yan, Li Chun-zhi, Hua Ming-jian, Zheng Yu-zhen, Yang Da-yu

1988, 8(1): 48-52.

[Abstract](1544) [PDF 2678KB](76)

Abstract:
The precipitate strengthening phases in AA2024-T62 have been investigated by TEM and HREM.It has been found that S' phase coexists with an ordered structore surrounded by strain field.The corresponding OFT analysis proves that the ordered structure produces additional diffraction spots.The aging process and aging mechanism of the A1-Cu-Mg Alloy have been discussed, Unlike current view，the aging process and growing process of S' phase can be described as follows:1.G.(1)G.P(2)S'+co-existing ordered structureS'+SS.2.Strain fieldCu,Mg atoms richco-existing ordered structureS'.

THE EFFECT OF THERMAL MECHANICAL TREATMENT ON THE MICROSTRUCTURE AND PROPERTIES OF GH169 DISC ALLOY

Zhang Guo-qing, Zhang Rong-wu, Yan Ming-gao

1988, 8(1): 53-58.

[Abstract](1503) [PDF 4187KB](81)

Abstract:
The Ni-Fe base GH169 disc alloy under normal heat treatment and two types of thermal mechanical treament(TMT)conditions has been studied in this paper,It was found that the segregation of alloy elements and the detrimental effect of -Ni3 Nb could be greatly reduced after the TMT.The experimental results indicated that the tensile strength and low cycle fatigue properties as well as the ductility of the alloy were increased substantially with its stress rupture lives comparable to that under the normal heat treatment condition, The improvement in the mechanical properties of the alloy after the TMT can be ascribed to the refinement of grain structures and the strengthening of the grain boundary region by dispersed granular c5 particals which, in turn，improve the fracture process of the alloy at elevated temperature，i.e.,from an intergranular rupture to ductile dimplefracture.

DEVELOPMENT OF Ni₃ A1 BASE SUPERALLOY

Sun Li, Han Ya-fang

1988, 8(1): 59-66.

[Abstract](1597) [PDF 4581KB](106)

Abstract:
Since intermelallic compound Ni3Al has some advantages, such as，high trength at elevated temperature, low density，high resistances to oxidation and corrosion，it is necessary to develop Ni，AL base superalloys for high temperature structures.However, the low ductility of polycrystal Ni3A1，relatively low strength in the temperature range below 700℃ and the sharp decrease of strength with temperature in the elevated temperature region make the development and application difficult, These problems have been solving recently, The ways to solve these problems have been discussed in this review combined with expcrimental work in this insti tute.The low ductility of polycrystal Ni3Al have beensolving by the development of Ni-rich Ni3Al base alloy systems and the addition of boron in these kind alloys.The improvement of strength has been achieving by the way of alloying to increase the part of non-metal chemical bond between atoms and the reverse precipitating of second phase particles when temperature raises,The criteria for the stability of LI2 tYPe structure and the composition design of Ni3Al base alloys have been discussed, and the chemical composition and mechanical properties of several developed casting polycrystal and DS Ni3Al superalloys have been also summerized in this literature review.

THE PROCESS AND MECHANISM OF MICRODAMAGE IN FINE GRINDING

1988, 8(1): 67-72,66.

[Abstract](1494) [PDF 3861KB](85)

Abstract:

PREPARATION OF ALUMINIUM POWDTR THIN FOIL FOIZ TRANSMISSION ELECTRON MICROSCOPY

Pan Ming-xiang

1988, 8(1): 73-75.

[Abstract](1498) [PDF 1795KB](90)

Abstract:

1988, 8(1): 76-78.

[Abstract](1597) [PDF 2321KB](102)

Abstract:

1988 Vol. 8, No. 1