航空材料学报

THE EFFECT OF DUAL SLOW CO0LING RATES TREATMENT ON ISOTHERMAL DEFORMATION OF P/M RENE'95

Cui Jian, Liu Jianyu, Li Chenggong, Yan Minpgao

1994, 14(3): 1-6.

[Abstract](1351) [PDF 258KB](210)

Abstract:
The effect of dual slow cooling rates treatment on isothermal deformation of P/M Rene'95 was studied.It was shown that the process of γ' precipitation especially the shape of γ'can be controlled by this treatment.At 1100℃ solution temperature,the flow stress of isothermal deformation of the alloy is lower when the second cooling rate is slower than the first cooling rate.

STUDY ON MICROWAVE ELECTROMAGNETIC PROPERTIES OF ULTRAFINEMETAL PARTICLES

Wang Zhiyong, Liu Junneng

1994, 14(3): 7-13.

[Abstract](1458) [PDF 405KB](332)

Abstract:
In this paper,microwave absorbing properties of two kinds of ultrafine Fe particles were investigated by theoretical analyses and experimental works,The radar absorbing mechanism for ultrafine Fe particles may be stated as free electron ohmic heating and magnetic energy losses.The results also show that characteristics of ultrafine Fe particles,such as shapes,microstructures,sizes and size-distributions and scattering states in the binders,have great influence on their microwave electromagnetic properties.

THE RELATIONSHIP BETWEEN MECHANICAL BEHAVIOR AND CARDON CONTENT,ISOTHERMALLYTRANSFORMEDMICROSTRUCTURE OF 300M ULTRA-HIGHSTRENGTH STEEL

Pu Ruhou, Zhang Wei, Zhao Zhenye

1994, 14(3): 14-18.

[Abstract](1341) [PDF 2332KB](265)

Abstract:
In this paper,the relationship between mechanical behavior and carbon content,isothermal temperature have been investigated.The results compared with those obtained by conventional quenching and tempering,show that 300M steel transformed with isothermal temperature below Ms has a mix structure of martenite,lower bainite and retained astenite.Tbe fracture toughness vary with the carbon content and the impact toughness decreases with increasing of carbon content.Both fracture toughness and impact toughness increase with increasing isothermal temperature.

STUDY ON THE RARE EARTH-ENRICHED PHASE PARTICALES OF AS-CAST AND MEL T-QUENCHED Ti-55 ALLOY

Li Geping, Wang Qingjiang, Guan Shaoxuan, Liu Yuyin, Li Dong, Hu Zhuangqi

1994, 14(3): 19-26.

[Abstract](1025) [PDF 408KB](135)

Abstract:
Transmission eletron microscope studies of melt-quenched Ti-5Al-4Sn-2Zr-1Mo-0.25Si-0.3～1.2Nd alloy show that spherical rare earth-enriched phase particles of 4～34nm in diameter distribute fairly uniformly in the matrix,besides which,ellipsoidal particles are aligned along the grain boundary.The as-cast Ti-5Al-4Sn-2Zr-1Mo-0.25Si-0.3～1.2Nd alloy is studied by using an image analyzer,The rare earth-enriched phase particles which nonuniformly distribute in grain and grain boundary are about 3.25～3.50μm in diameter.The average value of circularity shape factor is 0.56～0.63,and the shapes of particles are mainly ellipsoids,and a few kinds of irregular morphologies like needle and block,so its uniform degree is less than the rare earth-enriched phase particles in the melt-quenched Ti-5Al-4Sn-2Zr-1Mo-0.25Si-0.3～1.2Nd alloy.

INVESTIGATION ON LOWCYCLE FATIGUE OF ADIRECTIONALLY SOLIDIFIED SUPERALLOY

Wu Changxin, Xie Jizhou, Li Qijuan, Lin Shuxi, Sun Chuanqi

1994, 14(3): 27-34.

[Abstract](1384) [PDF 435KB](263)

Abstract:
The low cycle fatigue(LCF)properties of a directionally solidified(DS)superalloy have been studied at 760℃ and compared with that of the conventional cast(CC)superalloy with same composition as the DS alloy,It was showed that the fatigue life of DS alloy is twice higher than that of CC alloy under stress-control condition,and about 20 times higher than CC alloy under strain-control condition,The fatigue cracks in CC alloyinitiate in some defects,such as the porosities or the grain boundary conjucting to specimen surface,and growth inwards along the grain boundary,but in the DS alloy the fatigue cracks initiate at the transverse segment of longituthnal grain boundary or some pre-cracking carbides,and growth along the dendritic zone and cross the dendrites.

INVESTIGATIONON STATISTICAL LIFE OF ARMOURED GLASS BY EXPONENTIALDISTRIBUTIONMODEL

Wang Linsheng, Ma Juanrong

1994, 14(3): 35-41.

[Abstract](1452) [PDF 393KB](155)

Abstract:
In this paper,the parameter estimation on statistical life of armoured glass is investigated by exponential distribution model.The average life and the safety life at certain reliability are given and a new statistical method is proposed for site statistics.

A MICROWAVE PLASMA CVD SYSTEM FOR SYNTHESIS OF DIAMOND FILM

Huo Xiao, Ren Jialie, Lu Anli

1994, 14(3): 42-47.

[Abstract](1405) [PDF 349KB](270)

Abstract:
Amicrowave plasma CVD system,which has high power capability,reasonable configuration and operates stably,has been developed.In this paper,the basic configuration and performance of the system as well as its features are described.Using this system,a synthesis of diamond film on various substrates such as single crystal silicon has been achieved successfully.

APPLICATION OF THE d-ELECTRONS CONCEPT IN THE DEVELOPMENT OF SINGLE CRYSTAL SUPERALLOYS

Gui Zhonglou, Sun Li

1994, 14(3): 48-54.

[Abstract](1429) [PDF 400KB](143)

Abstract:
In this paper,the application of d-electrons concept in the development of single crystal superalloys is described.The d-electrons concept and desigri process of single crystal superalloys by this concept,which have an optimum combination of properties have been introduced.Using this concept,many realistic single crystal superalloys have been analised and discussed.

INGOT METALLURGY OF ALUMINIUM-LITHIUM ALLOYS

Grushko O. E.

1994, 14(3): 55-62.

[Abstract](1459) [PDF 450KB](152)

Abstract:
The developments and modification of ingots melting and casting methods of Al-Li alloys from Russian are introduced with the emphasis on the research results of the melting feature,melt oxidation,protection additions,fluxes and argon protection,nonmetallic impurities(oxygen,carbon,nitrogen,hydrogen),susceptibility to casting cracks(cold cracks and hot cracks),crystallization conditions,and ingots nonhomogeneous structure in Al-Li alloys.

1994 Vol. 14, No. 3