航空材料学报

THE STUDY OF γ' PRECIPITATON BEHAVIOR OF HIP+F PM RENE'95 SUPERALLOY DURING HEAT TREATMENT

Mao Jian, Yu Kelan, Zhou Ruifa

1989, 9(4): 1-9.

[Abstract](1384) [PDF 1975KB](164)

Abstract:
The quantitative relationship between solution temperature,cooling rate and γ' precipitate content and size distribution have been studied by optical quantitative metallography,which provides a basis for PM Rene'95 turbine disc heat treatment. The reaserch shows that the primary γ' precipitate content increases with the solution temperature till a maximum value reaches when the solution temperature is 1120℃,and then decreases with further increasing solution temperature. There exist more primary γ' and fewer grain boundary γ' in samples salt-bath quenched at 300℃ than water qnenched or oil quenched.The results of stress rupture tests shows that stress rupture life can be greatly impoved by salt-bath quenching at 300℃.

TRANSMISSION ELECTRON MICROSCOPY ON THE CRYSTAL STRuCTURE OF S' PHASE IN Al-Cu-Mg ALLOY

Jin yan, Li Chunzhi, Yan Minggao

1989, 9(4): 10-15.

[Abstract](1441) [PDF 1636KB](172)

Abstract:
In the present work,the crystal structure of S' phase in Al-4.9Cu-1.8Mg alloy has been studied by high-resolution electron microscopy(HREM),computer lattice-image simulation and the dynamical diffraction simulation.It was found that the previous two crystal structure models proposed by Mondolfo and Cuisiat respectively,were not consistent with the experimental results. therefore,the authors have given a new model which has been proved to be more close to the experimental results.It was suggested the S' phase has an orthohombic crystal structure with lattice parameters of a=0.400nm,b=0.461nm and c=0.718nm.There are four atoms in a unit cell with Al:Cu:Mg=2:1:1. The space group of the S' phase is Pmm2.

INFLUENCE OF SOME FACTORS ON FRACTURE TOUGHNESS OF 2124 ALUMINIUM ALLOY

Zheng Yuzhen, Liu Cunyu, Liu Jinfeng

1989, 9(4): 16-23.

[Abstract](1419) [PDF 1829KB](245)

Abstract:
The results in this research indicated that the fracture toughness decreases obviously with the increase of Cu,Mg,Fe and Si contents within chemical composition range specified in the standard of 2124 T851 aluminium alloy plate, but no obvious influence of grain size in plate and addition of B trace element on fracture toughness was observed.However,solution heat treatment bears an important influence on fracture toughness,the artificial ageing in the range of 185-195℃ for 9-16h has no obvious influence on KIC value of 2124 T851 aluminium alloy plate. For comparison KIC values of various type specimens taken from 2124 T851 plate used for this investigation were measured.The results show that KIC values measured with three-point bend specimens and compact specimens with straight through notch are equivalent,however KIC value of compact specimens with Chevron notch is lower 1.5MN/m3/2 approximately.

FR SERIES PROTECTIVE LUBRICANTS FOR HOTWORKING OF METALS AND ALLOYS

Li Guangyuan, Luan Huizhi

1989, 9(4): 24-31.

[Abstract](1401) [PDF 727KB](227)

Abstract:
FR series protective lubricants are both a kind of aqueous suspension conposed of silicate or boric silicate glass as matrix,modified silico-organic acrylic resin as adhesive and water as solvent. The FR series protective lubricants can fully meet the service requirements of high temperature viscosity,lubrication performance,protection and insulation function for precision forging and extrusion of various metals.Now the operating temperature range of FR series protective lubricants is 680～1200℃ and wide variety of near 20 types are successfully used for titanium alloys,superalloys, stainless steels and copper alloys. Principle of design and optimization of glass protective lubrications is also described.

STUDY OF RELATIONS BETWEEN VISCOSITYAND DEGREE OF CURE OF 5222 RESIN SYSTEM

Chen Yan, Wu Xuanzheng, Zhan Meizhen, Zhang Bishu, Tang Jianmao, Qi Zongneng

1989, 9(4): 32-37,45.

[Abstract](1505) [PDF 409KB](158)

Abstract:
In this paper,the viscosities of 5222 resin system as functions of the degree of cure were investigated.The mathematical models of the relationships were given in conclusion.The results show that there is an excellent agreement between the value of viscosity measured by Brookfield Model DV-I viscometer and the value of viscosity culculated by mathmatical models.

A NEW PARAMETER MEASURING SHOT PEENING INTENSITY

Li Jinkui, Yao Mei, Wang Renzhi

1989, 9(4): 38-45.

[Abstract](1506) [PDF 490KB](270)

Abstract:
On the basis of tests a new parameter measuring shot peening intensity,nondimensional diameter, was proposed in this paper. is proportional to depth of compressive residual stress field due to shot peening.Compared with Almen intensity (AI), is a better parameter to determine shot peening intensity.

CRACK PROPAGATION STUDIES ON AI 7475 ON THE BASIS OF CONSTANT AMPLITUDE AND SELECTIVE VARIABLE AMPLITUDE LOADING HISTORIES

Zhang Shijie, R. Marissen, K. Schulte, K. K. Trautmann, H. Nowack, J. Schijve

1989, 9(4): 46-56.

[Abstract](1425) [PDF 1163KB](165)

Abstract:
Fatigue crack propagation behaviour under variable amplitude loading is significantly influenced by load history induced sequence effects.In the present investigation an exploratory test program with simple variable amplitude load sequences was performed,which was designed to improve the general understanding of sequence effects and to offer a basis both for an evaluation of existing crack propagation prediction models and for the development of improved methods. In the first part of the study constant amplitude tests were performed over a wide range of R-ratios.The test results and the transition of the fracture mode during tests could be represented on the basis of the effective ΔK-value. In the second part of the paper tests with simple systematically varied sequences of high loads,low loads and underloads were performed and the crack propagation behaviour was measured.Finally,some general viewpoints regarding further developments of models are outlined.

CURRENT DEVELOPMENT OF SUPERALLOY TECHNOLOGY IN USSR

Huang Fuxiang

1989, 9(4): 57-64.

[Abstract](1397) [PDF 614KB](186)

Abstract:
This paper summarizes the main achievments in the field of cast,wrought and PM superalloy technology of USSR in recent years.The article also gives brief introduction to some new technique such as directional solidification and single crystal,electroslag remelting and plasma are remelting.ultrasonic treatment, oxide dispersion strengthening,etc.

1989 Vol. 9, No. 4