航空材料学报

INFLUENCES OF MODIFICATION AND REFINEMENT ELEMENTS ON THE STRUCTURE OF SiC PARTICLE-REINFORCED Al-Si CAST COMPOSITES

Gui Manchang, Wang Dianbin, Zhang Hong, Yang Minggao

1995, 15(3): 1-5.

[Abstract](1417) [PDF 257KB](185)

Abstract:
The influences of modification and refinement elements on the microstructure of SiC particle reinforce-ment Al-Si cast composite;produced by cast-stirring technique were studied.Experimental results showedthat the similar microstructure changes from the above elements addition were created in both the un-rein-forcement matrix alloy and the particle reinforcement Al-Si composites. Modification can change the eutec-tic silicon shape from plate and needle to fiber,and refinement treatment can decrease the grain size.

EFFECTS OF SOLIDIFICATION PROCESSING ON PARTICLE DISTRIBUTION IN PARTICULATES REINFORCED Al-4%Mg COMPOSITES

Xie Guohong, Li Songchun, Wang Wuxian, Wu Renjie

1995, 15(3): 6-12.

[Abstract](1457) [PDF 380KB](159)

Abstract:
The effects of solidification processing on particle distribution in SiC,Al2O3,SiO2 particle reinforcedAl-4%Mg composites were investigated.Based on theoretical analysis,a model of mass ratio of equiaxedcell and particle describing intensity of particle pushing was established.The model predictions were ingood accordance with experimental results.

MICROSTRUCTURE IN RAPIDLY SOLIDIFIED Al-Li ALLOY BY SPRAY DEPOSITION PROCESS

Cui Chengsong, Fan Hongbo, Lai Zhonghong, Shen Jun, Jiang Zuling, Li Qingchun

1995, 15(3): 13-18.

[Abstract](1372) [PDF 350KB](138)

Abstract:
Rapidly solidified Al-3.8Li-0.8Mg 0.4Cu-0.13Zr alloy was preduced by the novel spray deposition technique,and microstructure of the as-deposited and as-extruded alloys have been studied. The as-deposited mate rial is composedof many very fine equiaxed grains with the size of 5～20μm. Grains in the as-extruded alloy are "brick-like"in mor-phology. Oxide particles have not been found at the grain boundaries. The δ'precipitates are irregular in shape . Some δ'particles nucleate on theβ'particles and form co-deposited phases(β'-δ').The distance between δ'particles doesn't widenobviously with the aging time. Precipitation-free zones(PFZs)also exist along the grain boundaries and widen while thetested alloy is aged for longer time. Precipitation of equllibrium phases at the grain boundary enhances the formation andwidening of PFZ.

EFFECT OF Sb ADDITION ON THE SYNTHETICAL PROPERTIES OF TiAl BASED ALLOY

He Yuehui, Huang Baiyun, Qu Xuanhui, Lei Changming, Chen Linghui, Liu Yexiang, Xu Qiang

1995, 15(3): 19-24.

[Abstract](1481) [PDF 340KB](250)

Abstract:
The effect of Sb addition on the TiAl based alloy was investigated.It has been found by test that themechanical properties at room temperature of TiAl based alloy can increase and it's oxidatiOn resistanceimproves effectively by Sb addition. TEM analyses result shows that there are more deformed twins inTiAl + Sb alloy samples deformed by compression test at room temperature. There is a layer of compactoxide film in TiAl+Sb alloy after cyclic oxidation test for 900℃×48h.

A STUDY OF MODIFIED PHENOLIC CARGO LINERS WITH HIGH IMPACT RESISTANCE AND FIRE RESISTANCE

Bai Shucheng, Wang Yuan, He Lulin

1995, 15(3): 25-32.

[Abstract](1478) [PDF 492KB](128)

Abstract:
Accord ing to the present fire resistance and anti-impact toughness requiremen ts of the cargo liners used in com-mercial aircrafts,a resin system 4193 is developed by modifying the basic phenolic fire resistance components withtough active epoxy parts and nonactive vinyl polymer parts,The glass reinforced composite materials based on thisresin system have a satisfied match between rigid and impact toughness and the good fire resistance(FST)propertiesare not effected apprecially. The composite materials can meet the advanced airworthness requirements of the commercial aircrafts.

THEE FFECT OF STRENGTHENING TREATMENT ON ALUMINA-BASE CERAMIC CORESFOR SINGLE-CRYSTAL BLADES

Yang Yaowu, Cao Lamei, Cai Guanghui

1995, 15(3): 33-38.

[Abstract](1402) [PDF 416KB](316)

Abstract:
Alumina-base ceramic core materials for single crystal blades were especially strengthened,and the effect of strengthening treatment on the core rnicrostructure and properties was investigated.It was shownthat the strengthened cores present a microstructure of lamellar mullite crystal,while a 200℃ higher linear-dilatation peak temperature in comparison with unstrengthened cores and considerably improved elevated temperature properties have been obtained.

AN EXPERIMENTAL STUDY ON THE DIS50LUTION OF PRIMARY SILICON IN Al-Si HYPEREUTECTIC ALLOY

Zhang Rong, Geng Xingguo, Wang Liuding, Xiong Yuhua, Zhang Yuanwen, Liu Lin

1995, 15(3): 39-43.

[Abstract](1455) [PDF 274KB](290)

Abstract:
The dissolution behavior of primary silicon phase in Al-18.08%Si alloy melts has been studied by useof isothermal holding of the melt with quench interrupting and rapid solidification techniques. Resultsshow that the primary silicon could not be cornpletely dissolved even though the sample was kept at 1000℃up to 2 hours.The dissolution rate is decreased with the holding time. Rapid solidification experimentsconfirm that the primary silicon particles is of higher chemical stability In the alloy melt.

LIFE PREDICTION AND DAMAGE ANALYSIS OF A SINGLE CRYSTAL Ni-BASE SUPERALLOY UNDER COMPLEX STRESS CONDITIONS

Chen Guoliang, Guo Hong, Wu Zhongtang

1995, 15(3): 44-49.

[Abstract](1396) [PDF 391KB](173)

Abstract:
In this paper an attempt was made to derive a universal life prediction equation and catalogue damagesfor a typical fatigue-creep interaction condition. The equation was established on the basis of the fatigue-creep interaction fracture map and its maximum stress modified life equations,Asingle crystal Ni base superalloy DD3 was used to illustrate the applications of both life prediction and damage analysis. The results proved the methods were realistic,and the accuracy was acceptable.

RESEARCH ON THE RELATIONS BETWEEN OUT-OF-PLANE MOIRE METHOD AND PHASE METHOD

Cao Kang, Zhou Xianbin

1995, 15(3): 50-55.

[Abstract](1421) [PDF 338KB](215)

Abstract:
The fundaTnental laws of out-of-plane moire methed and phase methed for 3-D surface measuringare investigated by optical Fourier analyses.The basic relations and characteristics in the processes of noncontact,whole-field,3-D surface measuring are analysed.

STATISTIC ANALYSIS FOR CYCLIC STRESS-STRAIN

Xu Renping, Duan Xiaojian

1995, 15(3): 56-62.

[Abstract](1528) [PDF 409KB](220)

Abstract:
In this paper,the character of cyclic stress-strain is theoretically analysed by means of the randomprocess and the method for statistic measure is given,Cyclic stress-strain curve clan with distribution formis obtained from test result.

1995 Vol. 15, No. 3