航空材料学报

COMPUTER DETECTION AND ANALYSIS CALCULATION OF THERMAL PARAMETERS DURING DS OF SINGLE CRYSTAL SUPERALLOY

Tang Dingzhong, Zhong Zhenggang, Wang Yihu

1994, 14(1): 1-7.

[Abstract](1417) [PDF 409KB](182)

Abstract:
In this paper,a microcomputer system which measures and calculates the thermal parameters during directional solidification of single crystal superalloy and a mathematical model for thermal analysis has been described.The problem of interference at workshop was resolved and a set of microcomputer system which can be used for directional solidification technology study at workshop was set up.And the microcomputer system has been successfully used in the investigation of DD3 SC superalloy solidification process.The test shows that the solidification parameters which directly affect the microstructures and properties of S.C casting,such as temperature gradient,solidification rate are inconstant during the solidification of single crystal superalloy though the technology factors,such as shell mould withdrawal rate,heater temperature are constant.So the technology factors should be adjusted automatic ally according to the variation of solidification parameters to desirable solidification process.

STUDY ON SLOW COOLING RATE TREATMENT AND ISOTHERMAL DEFORMATION OF P/MRENE'95

Cui Jian, Liu Jianyu, Li Chenggong, Yan Minggao, Yu Baoluo

1994, 14(1): 8-16.

[Abstract](1493) [PDF 496KB](272)

Abstract:
The influence of slow cooling rate treatment on microstructure and isothermal deformation behavior of P/M Rene'95 alloy has been investigated and the possibility of reducing the flow stress during isothermal deformation is discussed.A disk of φ220mm was produced.The experimental results show that the size and distribution of γ'phase in the P/M Rene 95'alloy can be changed by slow cooling rate treatment,which in turn,promote the dynamic recrystallization and recovery procedure during isothermal deformation of this alloy.The mechanical properties of the disk were found to meet the specification of P/M Rene'95 alloy.

TENSILE FRACTURED BEHAVIOUR OF CAST Cr-BEARING Ti₃Al+TiAl ALLOYS AT ROOM TEMPERATURE

Zheng Yunrong, Zhao Linruo

1994, 14(1): 17-26.

[Abstract](1367) [PDF 551KB](145)

Abstract:
In this article,the tensile fractured process of Ti-44.9Al(at-%)and Ti-44.3Al-3Cr(at-%)alloys has been investigated.The results showed that Cr increased ductility of alloys.Improvement of ductility for Cr-bearing alloy is related to the formation of larger amount of γ-TiAl phase and duplex structure consisting of fine grain γ and α2 +γ.Cr promotes formation of the block-shaped α2 and β2 phases which impedes the long-distance slipping for γ phase obviously,Refining as-cast grains further or preparing single alloy with lamellar structure of α2+γ are target of development of cast α2+γ alloys.

STUDY ON THE HIGH CYCLE FATIGUE OF Ti₃ Al BASED ALLOY

Du Juan, Li Xueming, Gao Yang, Cao Chunxiao

1994, 14(1): 27-34,63.

[Abstract](1443) [PDF 507KB](200)

Abstract:
In this paper,the high-cycle fatigue properties of Ti-25Al-10Nb-3V-1Mo(at-%)alloy(designated as TD2 alloy),with three different microstructures of its bar,disc and ring,were studied at room temperature,650℃ and 700℃,The results indicated that This alloy possessed considerable high-cycle fatigue strength.The dislocation morphology and fractograph of its fatigue specimens with different microstructures were examined with TEM and SEM.Meanwhile,fatigue crack intiation and growth mechanism of TD2 alloy was discussed.The conclusion of this work might be helpful to apply Ti3Al matrix alloy as parts being worked in fatigue stress.

ANALYSIS ON STRAIN FATIGUE IN HIGH STRENGTH STRUCTURE STEEL 16NiCo

Hou Jingyong, Gu Tian

1994, 14(1): 35-42.

[Abstract](1373) [PDF 453KB](177)

Abstract:
The low cycle strain fatigue of 16NiCo steel was investigated in details,its cycle stress-strain behaviours were discussed and analysized.The results have shown that for 16NiCo steel,the strain fatigue strength is comparable to the same kind of AF1410 steel produced in U.S.A,and the cycle softening would occur during the cycle loading.In addition,the analysis and calculation for plastic strain energy have indicated that the best combination of the strength with ducility of 16NiCo steel can be achieved under standard heat treatment.

STUDY ON ANTIRADAR COATING FOR THE SUBMARINE STEALTH

He Shan, Xiong Kemin

1994, 14(1): 43-48.

[Abstract](1511) [PDF 356KB](602)

Abstract:
In this paper,a series of mechanical and environmental properties of the antiradar coating XFT-2 has been studied.The results show that it meets the specifications of the Radar Absorbing Material(RAM)for submarine application.The coating has a good prospects in submarine stealth.

DEVELOPMENT AND APPLICATION OF SUPER-HIGH STRENGTH ALUMINUM ALLOYS

Wu Yilei, LiYongwei, Qiang Jun, Li Chunyu

1994, 14(1): 49-55.

[Abstract](1680) [PDF 396KB](571)

Abstract:
In this paper,the development and application of super-high strength aluminum alloys abroard,such as BR96,7090,CW67 and 7055 were reviewed.The present status of 7A55 alloy has also been described briefly and the comparison of 7A55 alloy to its same kinds has been made.Compared with the common high strength aluminum alloys(such as 7075,7150),the super-high strength aluminum alloys(such as 7055,B96,7A55)have the higher strength and the similar ductility and toughness,which leads to their better ability on weight saving.Ats the IM supur-high strength aluminum alloy has the lower price than the PM product tR,the benefit of weight saving is marked still more,As the first super-high strength aluminum alloy made in our country.the main properties of 7A55 alloy is on a level with the similar alloys abroard.The developing prospects of 7A55 alloy have been made in this paper.

THE DEVELOPMENT AND APPLICATIONS OF POLYIMIDES

Wang Yan, Shi Guofang

1994, 14(1): 56-62.

[Abstract](1562) [PDF 466KB](235)

Abstract:
The development and applications of polyimides are reviewed in this paper,the applications include aerospace、 electron、 machinery and vehicle industries.The development trend and prospect of polyimides are also reviewed.

1994 Vol. 14, No. 1