共查询到17条相似文献,搜索用时 54 毫秒
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采用快速凝固技术在Al-3.18Ti-0.65C(wt-%)合金中获得了呈弥散分布的单一TiC相颗粒,尺寸为30-100nm,原子组成为TiC0.76,结合常规和快速凝固组织的分析对比,并以热力学分析为基础,研究和探讨了TiC相的形成过程和机制。 相似文献
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研究了新近开发的Al-Ti-C-B中间合金细化剂,检查了其显微组织及细化工业纯铝及含Zr铝合金的性能,并与Al-Ti-B中间合金细化剂进行了对比。结果表明:Al-Ti-C-B中间合金细化剂含有Al3Ti、TiB2和TiC三种第二相,它们形成尺寸细小弥散分布的多相粒子团,其细化工业纯铝晶粒的能力明显优于Al-Ti-B中间合金细化剂,并克服了Al-Ti-B中间合金细化剂易被Zr原子毒化的弱点。分析认为,Al-Ti-C-B中间合金优异的细化性能归功于多相粒子团表面凹陷处的物理化学作用 相似文献
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采用单辊旋铸技术制备Al-2.5Ti-2.5Fe,Al2.5Ti-2.5Fe-2.5V和Al-2.5Ti-2.5Fe-2.5Cr(at%,下同)合金薄带,利用X射线衍射(XRD)和透射电镜(TEM)分析了这些合金的急冷态和退火态组织。结果表明:快速凝固Al-2.5Ti-2.5Fe合金急冷态组织中存在Al3Ti和Al5Ti2两种初生相,快凝合金经400℃退火10h后,组织中出现了Al13Fe4相,在450℃退火,组织中析出了弥散Al3Ti相;快速凝固Al-2.5Ti-2.5Fe-2.5V合金急冷态组织中存在Al11V相和Al80V20相,400℃退火10h后,初生Al11V相转变为Al80V20相,且固溶在α-Al基体中的Ti,Fe以Al23Ti9相和Al13Fe4相的形式析出;快速凝固Al-2.5Ti-2.5Fe-2.5Cr合金急冷态组织中存在Al3Ti和Al13Cr2两种初生相,快凝合金经300℃退火10h后,组织中析出了Al13Cr2和Al3Ti两种弥散相,400℃退火10h时后组织中出现了Al13Fe4相。 相似文献
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研究了快速凝固Al-Fe-Ti-C合金的显微结构及退火过程中的相变。初始快凝态组织由α-Al微胞晶组成,在胞晶边界分布着较大并拉长的非晶相;在胞晶内部则为细小弥散的球状亚稳Al_6Re相(底心正交结构),Ti和C全部过饱和固溶于α-Al中。当773K退火5h时,非晶相转变为α_T-AlFeSi相(斜方结构),Al_6Fe相部分转变为片状Al_3Fe相(底心单斜结构),部分长大但仍保持球状和底心正方结构过饱和固溶于α-Al基体中的Ti和C则以TiC形式弥散析出。 相似文献
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本文探讨了Ti对Al-Si合金快速凝固组织特征的影响,结果表明,Ti引入Al-Si合金以后,降低了合金的过冷能力,使合金在较小的初始过冷度下即开始凝固,从而使合金快速凝固条带的起始凝固组织粗化,胞晶间Si的偏析程度加剧。 相似文献
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根据TiC/Ti3AlC/Ti3Al三相自生复合材料的结构,建立了热应力分析的4层嵌套模型,推导了热应力计算公式.并利用该模型计算了TiC/Ti3AlC/Ti3Al三相复合材料的热应力.计算结果表明各相及对应界面的法向应变和切向应变均较TiC/Ti3Al两相结构材料有所降低,这有利于防止材料发生界面脱粘损坏;在Ti3AlC界相中只产生较小的切向压应力,可大幅度降低Ti3Al基体相中的切向压应力,有利于防止Ti3Al基体发生拉裂破坏.对具有包覆结构的TiC/Ti3AlC/Ti3Al合金的显微力学性能进行了测试,Ti3AlC界相的存在,使增强体中心到基体的显微硬度和弹性模量呈梯度变化,有利于应力传递. 相似文献
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GUAN Shaokang TANG Yali SHEN Ningfu ZHAO DongshanZhengzhou Institute of Technology. Zhengzhou. ChinaHU HanqiUniversity of Science Technology Beijing. Beijing China 《金属学报(英文版)》1994,7(3):167-170
The icosahedral quasicrvstalline phase (i-phase)with the chemical composition of 82.4at%Al,8.8at?,3.6at%V and 5.2at%Si in melt spun Al-Fe-V-Si ribbons was found.It is suggested that the temperature and holding time of the melt prior to quenching are the important factors in the formation of the i-phase. 相似文献
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Jiang Xiangyang Chen Zhenhua Wang Yun Zhou Duosan Central South University of Technology. Changsha China 《中国有色金属学会会刊》1993,(1)
By means of rapid solidification, two Al_(65)Cu_(20)Fe_(15) powders were prepared with water and liquid N_2 as the respective cooling agent. Both powders are composed of a qnasicrystalline icosahedral phase and a crystalline hexagonal phase, with the water-cooled alloy having a higher crystalline phase content. In the isothermal an nealing process, the crystalline phase in the water-quenched alloy begins to decrease at 500℃ and then disap pears at 600~700℃. At about 800℃, new crystalline phases form, and at 900℃, the quasicrystalline phase disappears. Conversely, in the liquid N_2 quenched alloy, the quasicrystalline phase starts to decrease at about 500℃. and the hexagonal phase decomposes into new crystalline phases. At 700~800℃, the quasicrystalline phase disappears. For the water-cooled sample, the quenching at 100~200C makes the crystalline to quasicrystalline phase transformation start at a lower temperature and the crystallization of the quasicrystal occur at a higher temperature. For the liquid N_2 quenched alloy, the quenching at 100~400℃, did not affect its phase transformation at high temperature. 相似文献
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[1]V.K. Vasudevan and H.L.Fraser, Mater. Sci. Eng. 98 (1988)131.
[2]Y.C. Chen, M.E. Fine, J.R. Weertman and R.E. Lewis, Scripta Metall. 21(7) (1987) 1003.
[3]S. Sriram and J. Sekhar, Mater. Sci. Eng. 66 (1984) L9.
[4]G.K Dey., D. Prakash, R.T. Savalia, R.K. Mandal and S. Banerjee, Scr. Metall. 30 (1994) 1073.
[5]R.D. Fried, J.M. Zinded and H.L. Fraser, Scr. Metall. 20 (1986) 415.
[6]W.J. Bottineger, Metall. Trans. 17A (1986) 781.
[7]L.A. Bendersky, M.J. Kaufman, W.J. Bottineger and F.S. Biancaniello, Mater. Sci. Eng. 98 (1988)213.
[8]J.D. Cotton and M.J. Kaufman, Metall. Trans. A 22A (1991) 927.
[9]J. Perepezko, Mater. Sci. Eng. 65 (1984) 125.
[10]D.J. Skinner, R.L. Bye, D. Raybowld and A.M. Brown, Scr. Metall. 20 (1986) 867.
[11]R.E. Frank and J.A. Hank, Scr. Metall. 23 (1989) 113.
[12]L. Kubicar and S. Adamisova, International J. Rap. Solid. 8 (1995) 281.
[13]J.Q. Wang, PhD Dissertation, Northeastern University, Shenyang (1996) p.28.
[14]H.R. Kirchmayer, Z. Metall. 60 (1969) 699.
[15]G. Shao and P. Tsakiraprulos, Acta Metall. Mater. 42(9) (1994) 2937.
[16]Z.Y. Xu, Principle of Phase Transformation (Science Press, Beijing, 1988) p.151.
[17]H. Jones, Mater. Sic. Eng. A133 (1991) 33.
[18]D. Holland-Moritz and J. Herlach, Acta Mater. (5) (1998) 1601.
[19]M.T. Cavaguera-Mora and N. Clavaguerq, J. Alloys and Compounds 247 (1997) p.93.
[20]H. Jones, Phil. Mag. B 61 (1990) 487.
[21]H. Pang, PhD Dissertation, Northeastern University, Shenyang (1999) p.25. 相似文献
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H. Pang Z.H. Jin J.N. Deng and M.G.ZengShenyang National Laboratory for Material Science Institute of Metal Research CAS Shenyang ChinaCollege of Science Northeastern University Shenyang China 《金属学报(英文版)》2002,(5)
The microstructure of Al-Fe-V-Si-Nd alloy prepared by rapid solidification (RS) processing was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). The phase selection of the alloy during solidification and the nucleation behavior of Al8Fe4Nd phase were analyzed within the framework of time-dependent nucleation theory. The incubation time for Al8Fe4Nd phase was found shorter and the nucleation rate higher than those of α-Al. The results indicate the nucleation of Al8Fe4Nd phase is heterogeneous and the dispersoids of Al8Fe4Nd form as primary particles from the liquid, which is consistent with experimental observation. 相似文献