共查询到20条相似文献,搜索用时 15 毫秒
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W.H. Tian K. Ohishi M. Nemoto ) Department of Materials Physics Chemistry University of Science Technology Beijing Beijing China ) Department of Materials Science Engineering Faculty of Engineering Kyushu University Fuk 《金属学报(英文版)》2001,14(5):313-318
1. IlltroductionA significant improvement in the high temperature strength has been attained by form-ing a two phase mixture of B2-ordered NiAl and L21-Ni2AlTi (H phase) precipitates[1]. TheHeusler phaJse (Ni2AlTi) has a unit cell composed of eight B2 unit cells, in which Al andTi atoms occuPy ordered sites on one sublattice. Field et al.l2] studied the microstructuresof the allOys along line between the pseudobinary NiAl and Ni2AlTi and obtained an indi-cation of spinodal ordering in… 相似文献
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W.H. Tian A.L. Fan M. NemotoDepartment of Materials Physics Chemistry University of Science Technology Beijing Beijing ChinaSasebo National College of Technology Okishin - Sasebo - Japan Manuscript received July 《金属学报(英文版)》2002,15(3):253-259
且.工口止OOdllCt1OllThe BZ-ordered NIAI has received considerable attention because oflts pete尬lal forhightemperature applicatlonsll,2].Its ad皿ntages are high melting temperature,rel幼Ivelylow density ofs.959/cm’and good皿idatlon resistance at high 相似文献
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LIU Zhiguo CHEN Yong CAO Yanni Nanjing University Nanjing ChinaZHU Zhengsheng Shaanxi Iron Steel Institute Xi''''an China Professor Dept.of Physics Nanjing University Nanjing China 《金属学报(英文版)》1991,4(1):33-36
The microstructural evolution and precipitation hardening of an Elinvar alloy doped with Ti and Al during isothermal aging at 700℃ have been investigated by atom probe field ion microscopy and microhardness measurements.The γ′ precipiates are spherical and coherent with the matrix.The chemical composition of the precipitates are(Ni_(0.53)Fe_(0.47)_3 (Ti_(0.(?))Al_(0.4)). During aging,a Lifshitz-Wagner type dissolution and coarsening reaction of the precipitates has been observed,The hardness of the material varies with the aging time and reaches maxi- mum when the average diameter of the precipitates was about 11 nm. 相似文献
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1.IntroductionLlz-orderedC03Tihasat6ractedm1lchattentionbecauseofitsp0sitivetemperaturedependenceofstrengthI1t2],thehighesttemperatureatwhichthestrellgthattainsitshigh-estval..[2]andhighductilityoverawiderangeoftemperature[3].Thestrellgthlevel,however,isnotashighasthat0fNi3ALbasedall0ys[2].Acc0rdingt0thereI,ortedCo-Tibinaryphasediagram[']?theryi-C.,Tiphaseexistsoveracompositi0nrangeapproximatelyfrom2Ot025m0l%TiasshowninFig.l.Thes0lubility0fTiinCohasbeenwellestab-lishedbecausetheprecipit… 相似文献
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本文研究了含硼量为0-2.22at.-%的Ni_3Al在750-1150℃和3-100h条件下的氧化行为。结果表明,不同硼含量的Ni_3Al合金在不同温度下的氧化动力学曲线基本都符合抛物线规律。硼含量在0.52-1.37at。-%时抗氧化性能最好。研究了氧化膜的形态与结构。0-1.37at.-%B的Ni_3Al合金,表面形成以Al_2O_3为主的氧化膜,并含有少量NiO和NiAl_2O_4,含有2.22at.-%B的Ni_3Al合金,表面生成复杂的硼氧化物,破坏Al_2O_3膜的完整性,抗氧化性最差。但无硼合金中,NiAl_2O_4的含量最高,并在试样冷却过程中几乎全部剥离。 相似文献
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GUO Jianting SUN Chao LI Hui GUAN Hengrong Institute of Metal Research Academia Sinica Shenyang China GUO Jianting Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1990,3(7):38-42
The effect of boron content(0 to 2.22 at.-% )on isothermal oxidation behaviour of Ni_3Al at750 to 1150℃ for 3 to 100 h has been studied.The results show that the isothermal oxidationkinetics of Ni_3Al with various B contents at different temperatures obeys the parabolic law.The compounds with 0.52 to 1.37 at.-%B show the best oxidation resistance.The morphologyand microstructure of the scales have also been investigated. 相似文献
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Chang Suk Han 《Metals and Materials International》2008,14(3):291-295
A transmission electron microscopy (TEM) investigation of the morphologies and crystal structures of precipitates in supersaturated
B2-ordered (Ni,Co)Al has revealed that rod-like precipitates of the (Ni,Co)2Al phase with a hexagonal structure form parallel to the <111> direction of the B2 matrix. By aging at temperatures below
973 K, a long period superlattice structure of hexagonal (Ni,Co)2Al was formed. The (Ni,Co)Al hardens appreciably by the precipitation of these phases. An energy dispersive spectroscopy (EDS)
was used to analyze the compositions of each phase formed in the B2-(Ni,Co)Al. The effects of the dispersion of the (Ni,Co)2Al phase on the temperature dependence of the strength of the B2-(Ni,Co)Al have been investigated over a temperature range
from 298 K to 1173 K. 相似文献
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SURFACEREACTION,HYDROGENDIFFUSIVITYANDENVIRONMENTALEMBRITTLEMENTOFINTERMETALLICCOMPOUNDSNi_3AlANDFe_3AlWANXiaojing;ZHUJiahong;... 相似文献
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EFFECTS OF SMALL ADDITIONS OF Mg AND Ag ON PRECIPITATION PROCESS OF Al Cu Li (Mg) (Ag) Zr ALLOYS 总被引:1,自引:0,他引:1
Zheng Ziqiao Huang Biping Department of Materials Science Engineering Central South University of Technology Changsha P. R. China 《中国有色金属学会会刊》1998,(3)
1INTRODUCTIONInternaryAlCuMgaloyswithhighCu∶Mgmassratios,smaladditionsofMgpromotetheprecipitationofstrengtheningphaseswhich... 相似文献
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通过电子显微分析,发现在热等静压的TiAl-V-Si合金中有大量的硅化物沿层状结构的相界面析出,这些硅化物为Ti_5Si_3相,通常为近六角形的薄片.Ti_5Si_3相与层状结构基体相(α_2和γ相)间具有如下的固定取向关系[0001]_(Ti_5Si_3)//[0001]_(Ti_3Al),(3120)_(Ti_5Si_3),//(1010)_(Ti_3Al)[0001]_(Ti_5Si_3)//[111]_(TiAl),(4150)_(Ti_5Si_3)//(110)_(TiAl) 相似文献
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NiAl和Ni3Al双相合金的超塑性变形 总被引:1,自引:1,他引:1
研究了NiAl和Ni3Al双相合金在高温超塑性变形行为.结果表明:该合金在975至1025℃的温度范围及应变速率为152×10(-4)s(-1)时,表现出超塑性变形行为;1000℃时最大拉伸延伸率为149%,此时对应的应力敏感指数为0.375.该合金的超塑性形变可用经验公式ε=Aσ(2.67)exp(-303000/RT)来表示。对拉伸后试样的金相和TEM研究表明,合金中NiAl和Ni3Al两相在高温能够较好地协同形变,超塑性是由变形过程中发生的连续回复与再结晶过程来实现的. 相似文献
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粘土固化浆液塑性强度增长规律及其影响因素 总被引:2,自引:1,他引:2
王星华 《中国有色金属学报》1997,7(1):5-8
结构剂加量、水泥加量与粘土原浆粘度对粘土固化浆液的初凝时间都有影响,它们的影响程度各不相同,其中结构剂加量为2%时,初凝时间最短,仅几秒钟。粘土固化浆液塑性强度增长缓慢,早期强度低,后期强度(第18天的塑性强度)可达数兆帕,调整水泥加量、结构剂加量与原浆粘度可调节浆液塑性强度值 相似文献
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两阶段控制轧制后,采用不同的冷却路径进行冷却,研究冷却路径对Nb-Ti微合金钢组织和性能及沉淀行为的影响.结果表明,超快冷+空冷冷却路径可获得细晶组织,晶粒平均尺寸约为7.76μm,屈服强度高达425 MPa,抗拉强度高达500 MPa.超快冷+炉冷试样中存在细小的沉淀粒子,沉淀粒子尺寸主要集中在2-7 nm,而超快冷+空冷试样中只存在少量球形沉淀粒子,轧后直接空冷可获得相间沉淀粒子.不同冷却路径获得的热轧板在700℃下退火300 s后,沉淀粒子发生明显的粗化;退火处理后,超快冷+炉冷试样的晶粒平均尺寸减小为6.47μm,相对于退火前,其屈服强度和抗拉强度分别增加50和30 MPa,强度的增加主要源于细晶强化.对于含0.03%Nb(质量分数)的Nb-Ti微合金钢,由于沉淀粒子的体积分数有限,因此细晶强化效果远高于沉淀强化效果,强度的变化与晶粒尺寸的变化具有很好的对应性.另外,加工硬化指数与晶粒尺寸密切相关,随着晶粒平均尺寸的增加使加工硬化指数增加. 相似文献