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以无水乙醇为球磨助剂,采用机械球磨方法制备了纳米羟基磷灰石.钛(nHA-Ti)复合粉末。利用X射线衍射(XRD)、扫描电子显微镜(SEM)和能谱分析仪(EDS),研究了球磨过程中(5-40h)复合粉末的相组成和微观组织;通过电子探针(EPMA)对Ca元素面扫描,分析了球磨过程中复合粉末的均匀化效果。结果表明,随着球磨时间的延长,复合粉末逐渐细化和均匀化,球磨30h可使复合粉末形成nHA弥散分布在Ti大颗粒上的包覆状粉末结构,且复合粉末中nHA获得了较好的均匀化效果。 相似文献
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采用高能机械球磨和脉冲电流活化烧结方法制备了一种新型的β-钛合金基体的Ti35Nb2.5Sn/10HA生物复合材料。研究了机械球磨不同时间的Ti35Nb2.5Sn10HA粉体以及烧结样品的微观组织。结果表明:经机械球磨8h后,粉体中的α-钛开始向β-钛转化。当球磨时间达到12h时,球磨粉体中的α-钛相完全转化为β-钛相,而且得到超细尺寸的复合粉体。用球磨12h的粉末烧结制备的复合材料具有超细晶粒结构,烧结得到的复合材料的硬度和相对密度都随着球磨时间的延长而增加。 相似文献
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目的通过原位合成技术获得Ti(Al,C)复合粉末。方法在不同球磨时间条件下,采用机械合金化方法制备Ti(Al,C)复合粉末,其中Ti粉和Al粉的摩尔比为1:1。采用扫描电子显微镜(SEM)以及X-射线衍射仪(XRD)分析球磨后粉末的显微组织结构及物相,研究不同球磨时间对制备Ti(Al,C)复合粉末物相演变、组织结构及粒子间界面结合状态的影响。结果在球磨过程中,球磨时间越长,粉体的粒径越小,当球磨时间增长到一定程度时,延展性好的Al粉颗粒发生扁平化且其表面积不断增大,使得碎化后的Ti粉颗粒不断嵌入至Al粉颗粒中,最终形成Ti(Al)固溶体。同时根据XRD分析发现,随着球磨时间的延长,Ti(Al,C)复合粉末中的Al峰逐渐减小,说明Al不断固溶到Ti中,形成了一定量的Ti(Al)固溶体。结论通过机械球磨技术在球磨一定时间后可原位合成Ti(Al)固溶体,这说明随着Ti与Al之间的相互扩散,有利于形成Ti(Al)固溶体。 相似文献
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研究了机械球磨Ti50 Al50 复合粉的组织与压制特性。结果表明 ,球磨导致粉末硬度增加 ,压制特性变差 ,这是由于球磨使层片结构细化 ,Ti和Al组元晶体缺陷增加和晶粒细化造成的 ;但球磨 3h形成纳米晶复合粉后 ,尤其是在球磨 7.5h开始发生非晶转变后 ,进一步球磨 ,粉末压制特性变化并不明显 相似文献
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H. Amini Mashhadi I. BataevS. Tanaka R. TomoshigeK. Hokamoto 《International Journal of Refractory Metals and Hard Materials》2012,30(1):25-32
This paper reports on our study of the synthesis of titanium nitride solid solution by the reduction of aluminum nitride with titanium by mechanical alloying (MA) using a planetary ball mill. A nanostructure composite of in-situ titanium nitride solid solution was produced through exchange reaction between Ti and AlN. X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe micro analysis (EPMA), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and particle size analysis (PSA) were used to characterize the product. It was found that, with increased milling time, Al resulted from decomposition of aluminum nitride dissolved in the Ti lattice, leading to the formation of Ti(Al) solid solution and a reduction of the Ti lattice interplanar distance. Consequently, the Ti(Al) solid solution reacted with nitrogen to form in-situ Ti(Al)N nano particles. The milled powder had a spheroid shape and a very narrow size distribution of about 1 μm at the end of milling. In-situ Ti(Al)N particles with an average size of 10 nm were attained at a ball-to-powder weight ratio of 10:1 and a Ti:AlN molar ratio of 1:1. 相似文献
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以3Ti/Si/2C/0.2Al单质混合粉体为原料,采用机械合金化法制备Ti3SiC2材料.研究球磨工艺(球磨时间、球料比和球径大小、过程控制剂)对机械合金化合成Ti3SiC2影响.结果表明,机械合金化(球料比10:1,球径10 mm)单质混合粉体7 h后,原料粉体发生化学反应,生成了TiC和Ti3SiC2粉体和块体产物.球料比和球径大小对反应合成Ti3SiC2影响并不显著,但明显影响反应的孕育期.适当增大球径和球料比可明显缩短反应的孕育期,采用较大的磨球或过高的球料比会降低球磨效率,延长孕育期;添加过程控制剂(乙醇),不但会延长反应的孕育期,而且抑制反应合成Ti3SiC2. 相似文献
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机械合金化W-Ni-Fe纳米复合粉的制备及结构研究 总被引:3,自引:1,他引:3
W,Ni,Fe粉末按照91.16W6.56Ni2.26Fe和95W5Ni的成分配比进行了机械合金化(MA).通过调整球磨转速、球磨时间等工艺参数研究了其对粉末结构的影响,并对机械合金化粉末的物相、合金化特性、晶粒尺寸、点阵畸变及粉末形貌和颗粒度作了测定和分析讨论.机械合金化使晶粒细化并产生孪晶和位错.有利于原子扩散形成过饱和固溶体和非晶;高的球磨能有利于形成非晶相、晶粒细化和点阵畸变,350r/min球磨20h后晶粒尺寸可达25nm;输入的球磨能不同.粉末粒度的变化路径不同,但都会经历长大,变小和稳定三个不同阶段. 相似文献
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Ti and Ag powders were mixed with different ball milling time (1, 2, 5 and 10 h) and sintered into porous Ti–3Ag alloys. The samples were treated with hydrothermal treatment, and their apatite-inducing abilities were further evaluated by immersion in modified simulated body fluid. The results indicate that the high surface energy brought by powder refinement leads to the decline of Ag, but promotes the oxidation of Ti during the sintering process. Meanwhile, the hydrothermal treated porous Ti–3Ag alloys prepared by the powders ball milled for 10 h possess the best apatite-inducing ability. 相似文献
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高能球磨过程中Ti与BN的反应 总被引:1,自引:0,他引:1
通过研究高能球磨工艺制备纳米复合粉体过程中Ti与BN的反应过程和机理,对所制备粉体的显微结构进行了表征.实验结果表明,采用金属Ti和BN为原料,球磨10h后,即形成球状纳米复合粉体,其中球状粉体颗粒的尺寸在随后的球磨过程中基本保持不变.BN由于球磨而发生解理进而包裹Ti颗粒可能是形成稳定的球状纳米颗粒的原因.球磨30h后,Ti与BN开始反应生成TiN.TiN纳米粒子与未反应的Ti,B和BN共同形成平均粒径约100nm的、较均匀分布的球状纳米复合粉体. 相似文献
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QU Shengguan LI Xiaoqiang LI Yuanyuan HU Lianxi WANG Erde 《稀有金属(英文版)》2006,25(1):21-26
A TiAl alloy was fabricated by high-energy ball milling and subsequent reactive sintering from the mixed powders of Ti and Al. High-energy ball milling produced a kind of particular composite powders with an extremely fine altemative Ti and Al lamella structure. The composite powders not only possessed good consolidation and densification characteristics, but also resulted in the augment of nucleation rate of α and γ titanium aluminides during solid-phase reactive sintering After a series of processing, pressing, degassing, extrusion, and sintering, the resultant TiAl alloy presented high relative density and refined grain sizes of (α2 + γ) lamella and γ phases. The compressive yield strength of the sintered TiAl reached 600 MPa at 800℃. 相似文献
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采用高能球磨粉末冶金法制备了10vol%nano-SiC颗粒增强纯Al基复合材料,研究了球磨时间和硬脂酸含量对复合粉末粒度和纳米颗粒分散均匀性的影响规律,并对复合材料的微观结构和拉伸性能进行了研究.结果表明,随球磨时间的延长,SiC颗粒在Al 中的分散均匀性变好,而复合粉颗粒的粒径先减小后增大,在球磨时间为15 h、过程控制剂硬脂酸含量为2wt%时复合粉末粒径最小.并采用此优化的混料工艺,制备出综合性能良好祅ano-SiCp/Al复合材料,其抗拉强度达到392.7 MPa,较纯Al提高了164.9%,伸长率达10.41%,较纯Al有所下降.复合材料的断裂机制是微孔聚集型断裂. 相似文献
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Al-SiC powder preparation for electronic packaging aluminum composites by plasma spray processing 总被引:2,自引:0,他引:2
Powders of pure aluminum (Al) with 55 and 75 vol.% SiC particles were ball milled in a conventional rotating ball mill with
stainless steel and ZrO2 balls for 1–10 h. The morphology and microstructure of the milled powders have been observed and analyzed by scanning electron
microscopy (SEM) and energy dispersive x-ray (EDX). The milled powders were plasma sprayed onto a graphite substrate to obtain
Al matrix composites with high SiC volume fraction. SiC particles in the milled powders existed in two forms; i.e., the combination
of Al into composite powder and individual. Plastic Al particles were broken during ball milling, and fine Al particles can
be coated onto the surface of SiC particles. Iron contamination in the milled powders occurred when stainless steel balls
were used. The iron level can be effectively controlled by using ZrO2 ball media. The milling efficiency by ZrO2 balls is inferior to that by stainless steel balls. Longer milling time was required with ZrO2 balls to achieve the same effect as obtained with stainless steel balls. SiC particles in the sprayed composites from the
milled powders exhibited a reasonably uniform distribution and high volume fraction. 相似文献
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用高能球磨法制备Ti50Ni22Cu25Sn3非晶粉末,并研究球磨工艺参数对Ti50Ni22Cu25Sn3非晶形成过程的影响。结果表明,球磨转速以及磨球直径对Ti50Ni22Cu25Sn3非晶相的形成效率具有十分重要的影响。较高的转速和合适的球径能有效促进该Ti基合金的非晶化,缩短合金非晶化的时间,当转速为400 r/min,球料比为20:1时,球磨时间约为30 h后,可得到完全的Ti50Ni22Cu25Sn3非晶粉末 相似文献
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MoSi2–CrSi2 nanocomposite powder was successfully synthesized by ball milling of Mo, Si and Cr elemental powders. Effects of the Cr content, milling time and annealing temperature were studied. X-ray diffraction (XRD) was used to characterize the milled and annealed powders. The morphological and microstructural evolutions were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). High temperature polymorph (HTP) of MoSi2 begins to form after 50 h of milling and completes after 70 h of milling. MoSi2–CrSi2 composite powder was also prepared with a combination of short milling time (50 h) and low temperature annealing (850 °C). Annealing led to the HTP to low temperature polymorph (LTP) transformation of MoSi2. MoSi2–CrSi2 nanocomposite powder with the mean grain size less than 50 nm was obtained at the end of milling. This composite maintained its nanocrystalline nature after annealing. A spherical morphology was procured for 50 h milled powder with 0.25 mole Cr. 相似文献
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通过机械球磨法制备原子比为4:1的Cr-W预合金粉末,对球磨后的Cr-W粉末进行XRD、SEM、TEM分析,探讨球磨时间对Cr-W粉末形貌、晶粒大小、组织结构及烧结Cr-W合金固溶度的影响。结果表明:采用机械合金化法,可以制备纳米级的Cr-W预合金粉末;球磨初期,晶粒尺寸、微应变变化较大,48 h后趋于稳定获得小于30 nm的纳米晶粉末;经72 h球磨后,粉末中有固溶体形成;球磨过程伴随着晶格常数的变化;球磨时间越长的粉末,烧结后各相分布越均匀,固溶程度越高 相似文献
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WTi alloy, which is a candidate of the gasket material used for the neutron high pressure diffraction, was proposed and fabricated by the powder metallurgy method in this paper. The laser particle size analyzer, scanning electron microscope, and transmission electron microscope were used to study the effects of milling time on the particle size distribution and the microstructure. The results show that with the extension of milling time, the particle size of the milled powders decreases, and the grain size of the sintered alloys also decreases. However, the oxygen content increases, and the αTi phase gradually appears and its amount increases with the increase of the milling time. The microstructure is composed of the W-rich (βTi,W) phase, the αTi phase and the eutectic phase before the milling time of 2 h, and after that the eutectic phase disappears. Oxygen coming from the milling gets rich in titanium so that it makes more and stable αTi phase. This is because, with the extension of milling time, the oxygen content is so high that the αTi phase can be very stable and the diffusion of W into Ti at the high temperature is suppressed. Moreover after 0.5 h ball milling, the maximum strength of the alloy is 3323 MPa due to the uniform microstructure. 相似文献