PROSPECTIVE DEVELOPMENT OF AVIATION MATERIALS

ＰＲＯＳＰＥＣＴＩＶＥＤＥＶＥＬＯＰＭＥＮＴＯＦＡＶＩＡＴＩＯＮＭＡＴＥＲＩＡＬＳＲ．Ｅ．Ｓｈａｌｉｎ（ＳｔａｔｅＲｅｓｅａｒｃｈＣｅｎｔｅｒ,Ａｌｌ－ＲｕｓｓｉａｎＳｃｉｅｎｔｉｆｉｃＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＡｖｉａｔｉｏｎＭａｔｅｒ...     

PREPARATION OF Al－Si INGOTS WITH FULL EUTECTIC－LIKE MICROSTRUCTURE AT LOW COOLING RATE

ＰＲＥＰＡＲＡＴＩＯＮＯＦＡｌ－ＳｉＩＮＧＯＴＳＷＩＴＨＦＵＬＬＥＵＴＥＣＴＩＣ－ＬＩＫＥＭＩＣＲＯＳＴＲＵＣＴＵＲＥＡＴＬＯＷＣＯＯＬＩＮＧＲＡＴＥＷＥＩＰｅｎｇｙｉ;ＦＵＨｅｎｇｚｈｉ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｏｌｉｄｉｆｉｃａ...     

IN SITU TEM STUDY ON THE R-PHASE TRANSFORMATION IN TiNi ALLOY

ＩＮＳＩＴＵＴＥＭＳＴＵＤＹＯＮＴＨＥＲ－ＰＨＡＳＥＴＲＡＮＳＦＯＲＭＡＴＩＯＮＩＮＴｉＮｉＡＬＬＯＹＣＨＥＮＱｉｎｇ;ＷＵＸｉｎｇｆａｎｇａｎｄＣ．Ｊ．Ｈｕｍｐｈｒｅｙｓ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＰｈｙｓｉｃｓ,Ｕｎｉｖｅｒｓｉｔ...     

SMALL ANGLE NEUTRON SCATTERING INVESTIGATION OF Ni_(50)Mo_(50) ALLOY AND ITS FRACTAL PROPERTIES

Small angle neutron scattering(SANS)technique has been used to investigate theNi_(50)Mo_(50) system prepared by mechanical alloying(MA).Significant changes of the scat-tering intensity have been observed among the sumples with different milling time.Inter-esting fractal-like behavior of the sample system have been found and attempts have beenmade to determine the fractal dimensions.It is expected that the fractal dimension can berelated to the different stages of MA to some extent.     

一种定向凝固高温合金的薄壁效应研究

采用定向凝固无余量精铸工艺，制造了接近于空心涡轮叶片的２和壁厚的管状薄壁试样，研究了一种定向凝固高温合金的薄壁性能，结果表明，薄壁试样的持久性能与标准试样相比没有明显的下降，说明在本试验条件下，该合金的薄壁效应不明显，从工艺因素和显微组织方面讨论了试验结果。     

Photons, Fibres and Defence

1IntroductionSerousresearchonopticalfibresforinformation~missionbeganinthemiddle1960's,i.e.over30yearsago.Somelabalsyearslaterpracticalapplicationsofsilica-basedopticalfibresinciviltelecOllUntalcationbegan.SinCethenOPticalfibreshavecompletelyrevoluti...     

A CELLULAR AUTOMATON-APPROACH TO SIMULATION OF GRAIN STRUCTURE DEVELOPMENT IN ELECTROSLAG CASTING

1.IntroductionElectroslagcastingcanproducepartsofgoodquality,ofwhichthemechanicalpropertiesarecomparablewithorsuperiortothoseofforgedproducts.Ithasbeenmoreandmoreutilizedtomakestructuresofcriticalimportance,whichconventionallywoulddoubtlesslybemadebyforging.Understandingandcontrolofmicrostructures,especiallyshape,sizeandorientationofcrystallitesinelectroslagcastingarethereforemoreandmoreimportantforsafetyconcernintheirapplication.Experimentalstudiesofthegrainstructuresandtheirdependenceonvario…     

STUDY ON SYNCHRONIZER HUB PLASTIC FORMING

1.~onItisessentialformakingtechnologyandoptimizingthedieconstructiontostudytheflowprincipleOfmetal.ThemethodsthatstudytheflowprincipleofmetalincludePhysicalstimulationandnumericalstimulation.BetWeenbothtwokindsofmethods,physicalstimulationhasthedisadvantagesOflongPeriodictime,heaVyinvestment,andthetotaldeformationprocesscannotbeobserveddirectly.However,numericalstimulationcanforeseethestatusOfmetalbilletinthediecavitythroughcomputerstimulation,beforethedieismade.Anditcanalterprocessschemean…     

MICROSTRUCTURE OF Mg-Zn-Zr-Y ALLOYS

In the as-cast Mg-Zn-Zr-Y alloys.the quasierystal phases show massive and eutectoidplate morphologies.The selected area diffraction(SAD)revealed that a large part of the quasicrystals are face-centered icosahedral(FCI),while a small amout of the quasierystals belong to the simple icosahedral(SI)phase.It was found that in homogenized alloys,a part of the grain boundry phases was dissolved,and small massive W-phase and lath-shape MgZn_2 phase dispersedly precipitate in the grains.The transformation of the quasicrystals relates to the temperature.After homogenizing at 360℃,the quasicrystals still present,while after homogenizing at 400℃,the quasicrystals transformed into a new C-typeorthorhombic phase with a=0.975nm,b=1.137nm and c=0.935nm.     

INVESTIGATION ON MECHANICALLY ALLOYED SUPERSATURATED NANOCRYSTALLINE Al-Ti ALLOYS

The Al_(100-x)Ti_x(x=5,10,15,35) mixed powders were mechanically alloved in a planetaryball mill.It was found that the initial compositionstribgkt affects the final oridycts a nix-true of supersatureated solid solution Al(Ti)and a fcc phas for x=5 and 10;and a singlesupersaturated solid solution Al(Ti)for x=15 and 35.With increasing Ti contents from5at% to 35at%,the grain size of soild solution Al(Ti)deereased from 40mm to 10mm.Theresults suggest that fast diffusion along nanocrystalline grain boundary is the main alloyingProcess. DSCcurves and TEM observationindicate that the sokyte atom segregation canthermally stabilize the nanocrystalline solid solutions.