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T.G.Nieh J.Wadsworth Lawrence Livermore National Laboratory L- P.O.Box Livermore CA U.S.A. 《中国有色金属学会会刊》1999,(Z1)
1 INTRODUCTIONγTiAlalloysareattractivestructuralmaterialsbecauseoftheirpotentialapplicationsinaerospaceandautomobileindustries[1].CurrentresearchonγTiAlisprimarilyfocusedonimprovingitsroomtemperatureductility,toughnessandhightemperaturecreepre… 相似文献
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W.J. Zhang Z.C. Liu G.L. Chen State Key Laboratory for Advanced Metals Materials University of Science Technology Beijing Beijing China Y. W. Kim Material Research Division Universal Energy Systems Dayton OH U.S.A. 《中国有色金属学会会刊》1999,(Z1)
1 INTRODUCTIONInrecentyears,anumberofpapershavestudiedthedeformationstructureofTiAlbasealloysinanattempttoimproveitsductility[1-6].IthasbeenclaimedthatthehighCRSSfor〈110]ordinaryslipinAlrichsinglephaseTiAlalloysisresponsiblefortheirlackofductilit… 相似文献
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1 INTRODUCTIONγTiAl/α2Ti3AltwophaseintermetallicsorTiAlalloyhasrecentlyreceivedincreasingattentionbecauseofitspotentialasastructuralmaterialforhightemperatureapplications,whicharisesfromitselevatedhightemperaturestrength,lowdensityandgoodoxidatio… 相似文献
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The decomposition of the β phase during rapid cooling of the near β titanium alloy Ti–5Al–5Mo–5V–3Cr has been studied using in situ X-ray synchrotron diffraction combined with ex situ conventional laboratory X-ray diffraction and transmission electron microscopy (TEM). Evidence is found supporting the suggestion by De Fontaine et al. (Acta Mater. 1971;19) that embryonic ω structures form by the correlation of linear (1 1 1)β defects at high temperatures. Further cooling causes increased correlation of these defects and the formation of athermal ω structures within the β matrix at temperatures ~500 °C. Post-quench aging at 570 °C resulted in the nucleation of α laths after ~90 s at temperature, with the laths all initially belonging to a single variant type. Aging for 30 min produced an even distribution of α precipitates with a lath morphology ~1.5 μm × 0.2 μm in size composed of both the expected Burgers variants. Mechanical property data suggests that the ω structures alone have no real effect; however, hardness increases were observed as the α phase developed. The utilization of thermal regimes similar to those presented in this paper could offer a method to engineer the α phase in near β titanium alloys and hence control mechanical properties. 相似文献
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利用分离式Hopkinson压杆,对Ti5Mo5V2Cr3Al(TB10)合金帽形试样进行强迫剪切试验,通过光学显微镜和透射电镜技术观测其绝热剪切带(ASB)内的微观结构。结果表明,ASB的过渡区由具有高位错密度的沿着剪切方向的宽度为20~50nm的拉长组织构成;剪切带中心由大量低位错密度(相对ASB的过渡区)的直径为50~100nm的晶粒组成,具有典型的再结晶组织特征。在绝热剪切变形过程中ASB内的平均绝热温升约为784℃。ASB内发生了动态再结晶,晶粒尺寸为50~100nm。 相似文献
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介绍了某型号小型高压容器的结构特点和技术要求;分析半奥氏体沉淀硬化不锈钢0Cr12Mn5Ni4Mo3Al的焊接性和气瓶的焊接技术难点;制订了焊接工艺方案;详细说明了高压容器试制时的焊接过程和控制焊缝缺陷及焊接变形的方法与措施.探伤与液压试验和爆破试验的结果表明:首批试制的高压容器的焊接质量符合设计要求,工艺方案完全适合于小型、薄壁、偏心、细直径高压容器的焊接加工.现已进行了多个批次的生产,焊接质量稳定,并且满足设计要求. 相似文献
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1.IntroductionTwo-phase(a2 7)TiAl-basedall0ysarecurrentlyunderextensiveinvestigationbe-causetheirmechanicalpr0pertiesaresuperi0rtoeitherthesinglephasecr20rtheryall0ysl1].Themicrostructureofthetwo-phasealloyswasf0undtohaveastronginfluence0ntheme-chanicalpr0pertiesI2].Themainmicrostructuralcharacteristics0ftheall0yswithlamellarstructurewhichconsistsofalternatinglayers0f0rdered7anda2lamellaewiththecri-entationrelati0nship{lll}./(OOO1)..3<11O>./<1120>.,)havebeenstudiedindetailbymanyinvestigat0r… 相似文献
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某0Cr12Mn5Ni4Mo3Al不锈钢自锁螺母在服役过程中出现开裂。对开裂螺母进行了宏观和微观断口形貌观察、表面能谱分析、显微组织及力学性能分析与测试等。结果表明:该螺母开裂原因为应力腐蚀开裂(SCC)。裂纹起源于法兰面与螺母体交接处,螺母体与法兰面呈直角此处易积液,螺母表面处理方式为钝化和涂MoS2,其耐蚀能较差。在腐蚀性潮湿大气环境中,干湿交替作用下螺母产生局部腐蚀点,在腐蚀点处萌生裂纹,裂纹在螺母圆周切向拉应力作用下扩展直至螺母开裂。 相似文献
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用透射电镜及备有拉伸装置的S570扫描电镜,研究了Ti3AlNb(Ti24Al14Nb3V0.5Mo)(摩尔百分数)合金在不同热处理制度下的组织形貌以及试样的拉伸断裂过程。结果表明:合金在α2+β两相区固溶1h水冷处理,组织由α2相、B2相和o相组成。初生α2相体积分数不同,合金试样拉伸断裂机制不同,初生α2相体积分数低时,变形主要在B2相,裂纹主要在B2相内形核,随着B2相的减少,合金塑性提高。初生α2相体积分数高时,变形主要在α2相,裂纹主要萌生于α2相内,随着B2相的增多,合金塑性提高。细小的随机分布的针状α2相对合金拉伸断裂行为有良好作用。随固溶温度升高,α2相中位错密度逐渐减少,B2相中位错密度逐渐增多 相似文献
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JIN Yan LI Chunzhi ZHAO Yingtao YAN Minggao Beijing Institute of Aeronautical Materials.Beijing China 《金属学报(英文版)》1992,5(2):69-75
The microstructure of 7050 AI alloy in T74 condition has been studied by means of transmis-sion electron microscopy and dynamical diffraction simulation.It was found that the alloystudied contains mainly AI3Zr superlattice phase,η′-phase and Al_7Cu_2Fe constituent phase.The η′-phase has an orthorombic crystal structure with a=0.492 nm,b=0.852 nm andc=0.701 nm.The orientation relationship between the η′-phase and matrix was determinedas(101)_m∥(010)_(η′)[111]_m∥[001]_(η′) 相似文献
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Wu Ying Zhen Liang Yang Dezhuang School of Materials Science Engineering Harbin Institute of Technology Harbin Liang Wei Detecting Center Taiyuan University of Technology Taiyuan 《中国有色金属学会会刊》1997,(3)
ANINSITUSTUDYONDISLOCATIONBEHAVIOROFCRACKTIPINTi3AlNbALLOY①WuYing,ZhenLiang,YangDezhuangSchoolofMaterialsScienceandEnginer... 相似文献
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Al—Ti—B晶粒细化合金中的有效形核相 总被引:23,自引:3,他引:23
研究了AlTiB晶粒细化合金中各化合物相TiAl3、TiB2和AlB2对铝晶粒的细化作用。结果表明,TiAl3相是有效形核相,TiB2和AlB2相不能单独作为形核相,B对AlTiB的细化作用有显著影响,但B及硼化物不能单独影响细化过程,而是富集在TiAl3相中对细化过程产生重要影响。 相似文献
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Wu Ying Zhen Liang Yang Dezhuang School of Materials Science Engineering Harbin Institute of Technology Harbin 《中国有色金属学会会刊》1997,(1)
TENSILEDEFORMATIONANDFRACTUREBEHAVIOROFTi3AlNbALLOYATHIGHTEMPERATURE①WuYing,ZhenLiang,YangDezhuangSchoolofMaterialsSciencean... 相似文献
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Wu Ying Liang Wei Cui Yuexian Li Daoming Yang Dezhuang School of Materials Science Engineering Harbin Institute of Technology Harbin 《中国有色金属学会会刊》1997,(2)
EFFECTOFTESTTEMPERATUREONDEFORMATIONMECHANISMOFTi3AlNbALLOY①WuYing,LiangWei,CuiYuexian,LiDaoming,YangDezhuangSchoolofMateria... 相似文献
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Wu Jinming Wu Nianqiang Wang Guangxin Li Zhizhang Department of Materials Science Engineering Zhejiang University Hangzhou 《中国有色金属学会会刊》1997,(3)
INSITUOBSERVATIONOFSINGLE-POINTWEAROFPMAlTiALLOY①WuJinming,WuNianqiang,WangGuangxin,LiZhizhangDepartmentofMaterialsSciencea... 相似文献
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Ti-24Al-14Nb-3V-0.5Mo合金的超塑性 总被引:2,自引:0,他引:2
研究了温度及应变速率对Ti-24Al-14Nb-3V-0.5Mo(at.-%)合金超塑性能的影响.试验结果表明,在980℃,3.5×10~(-4)s~(-1)的最佳超塑变形条件下,合金显示出较高的超塑性;应变速率敏感性指数m为0.69,拉伸延伸率El.为818%.根据其细小的α_2+β_0两相组织和等温拉伸的试验方法,确定合金的超塑性属于细晶组织超塑性.在超塑变形过程中,合金无空洞产生,显微组织发生动态粗化. 相似文献