航空材料学报

CURRENT DEVELOPMENT OF X-RAY ANALYSIS OF STRUCTURE AND STRESS CONDITION IN SUPERALLOYS

A. E. Samoilov, E. A. Eglatova, A. E. Clifok

1992, 12(2): 1-22.

[Abstract](1282) [PDF 1138KB](143)

Abstract:
This paper describes in detail the development of X-ray analysis of structure and stress condition in superalloys.

INVESTIGATION ON CAST Cr-BASE SUPERALLOY K25

Yang Qingfen

1992, 12(2): 23-30.

[Abstract](1409) [PDF 733KB](145)

Abstract:
A Cr-base cast superalloy K25 for reheat igniter diverter of aeroengines has been developed. It was shown that K25 alloy possesses high melting temperature, high elestic modulus and low density. Its oxidation resistance and thermal fatigue property is excellent, the alloy without any coating may serve at 1600℃ for shorter term and may be serviced for long time at alternating temperature of 700℃. K25 alloy’s composition is simpler, hence the cost is lower. The igniter made from K25 alloy for a aeroengine has been engine-tested for 422 h, but the componet is not still be failed and may serve the engine continueously. It is proved that the igniter made from K25 alloy has much longer life than that from ZGH30, a being previously used alloy.

AN ANALYSIS OF BRITTLENESS AT ROOM TEMPERATURE OF NiAl-BASE ALLOY

Zhao Xihong, Han Yafang

1992, 12(2): 31-39.

[Abstract](1443) [PDF 2081KB](170)

Abstract:
In this paper the mierostructure of Ni-20Al-30Fe alloy, the fracture behavior and the influence of the specification of heattreatment on. the microstructure of the alloy have been studied.The cause that microstructure of the alloy have been studied. The cause that this alloy can attain higher percentage elongation under room temperature has been analyzed. By adding 3.0at% Ti and 8.0at% Ti respectively, the influence of Ti on the microstructure, on the fracture behavior and on the change of the microstructure after heattreafment of the alloy was compared. The results show that the addition of Ti makes the alloy more brittle, The cause of the embrittemcnt was analyzed.

OPTIMIZING STRENGTH-DUCTILITY IN Al-Li ALLOYS

Chen Zheng, He Ming

1992, 12(2): 40-46.

[Abstract](1484) [PDF 1043KB](154)

Abstract:
According to the Research results about fracture feature and properties of monotonic tension for Al-Li alloys 2090 and 2050+Ce, the theory of ligament strengthening and delamination strengthening was presented, which belonging under extrinsic strengthening. The relationship among grain structure, strength difference between grain-within and grain boundary, stress localization degree at grain boundary and extrinsic strengtheling effect was researched. The method and mechanisms of optimizing strength-ductility was discussed, including grain stucture, minor rare earth element Ce, thermomechanical treatment and aging procedure.

THE EFFECTS OF MICROSTRUCTURE AND TENSILE DUCTILITY ON THE LOW CYCLE FATIGUE PROPERTIES OF TC 11 TITANIUM ALLOY

Liu Xijiang, Zhang Baochang, He Ming

1992, 12(2): 47-54.

[Abstract](1432) [PDF 506KB](158)

Abstract:
The influence of different regimes of heat treatment on the structure, tensile properties and low cycle fatigue properties of TC11 titanium alloy, and the relation of tensile ductility with Nt of this alloy have studied in this paper. The resuits show that the difference of low cycle fatigue life (Nf) between plate-like and equiaxed structure is diminished during decrease in amplitude of strain, and if the amplitude of strain is minor, the effects of ductility on Nf is little. In the process of fatigue the plate-like and equiaxed structure all appear as cyclic softening character. Plate-like structure selection for construction material of titanium discs and other parts working in high temperature is preferable to equiaxed structure.

STUDIES ON ABRASIVE WEAR PROPERTIES OF DISCONTINUOUS SiC REINFORCED ALUMINUM ALLOY COMPOSITES

Shen Hongwei, Bi Jing, Ma Zhongyi, Lu Yuxiong, Gao Yinxuan

1992, 12(2): 55-61,30.

[Abstract](1375) [PDF 1032KB](171)

Abstract:
The abrasive wear behaviour of SiC whisker (SICw) and SiC particulates (SiCp) reinforced 2024Al and 2124Al composites by powder metallurgy processes has been investigated using a pin-on-disk machine, and worn surface has also been observated by the use of scanning electron microscope. The results show that the composites exhibit obviously higher abrasive resistance compared with the unreinforced matrix alloy. The abrasive resistance of the composites is mainly dependent on the content and size of reinforcement. The abrasive resistance of 30% volume fraction SiC particles (20μm) reinforced 2024Al composites is five times greater than that of the matrix alloy.

AUTOCLAVE AND ITS RELATED TECHNIQUE

Cui Shengrui, Lang Yefang

1992, 12(2): 62-70.

[Abstract](1436) [PDF 1260KB](166)

Abstract:
This paper introduces some applications of the autoclave in China and on abraod, and the technical claims of curing composites and the model autoclave, a closed system, is presented. Meanwhile the speciel inspections and detections of high pressure vessels have been conducted. The monitor of curing process, an on line system, has been fulfilled in the autoclave. The curing process can be controlled and the high quality composites can be made in the system.

RESEARCH AND DEVELOPMENT FOR COMPOSITE RADAR ABSORBING MATERIAL (RAM) AND RADAR ABSORBING STRUCTURES (RAS)

Mo Meifang, Liu Junnebg

1992, 12(2): 71-81.

[Abstract](1550) [PDF 780KB](641)

Abstract:
This paper summarizes in the research, application and development of cmmposite radar absorbing material (RAM) and radar absorbing structures(RAS). Role of low observable composite in the reduction of Radar Cross Section (RCS) have been discussed.Application of radar absorbing materials and radar absorbing structures on the stealth aircraft is presented.

1992 Vol. 12, No. 2