共查询到19条相似文献,搜索用时 109 毫秒
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以Fe33Si67(原子分数)为研究对象,采用机械合金化方法制备β-FeSi2热电材料。用X射线衍射(XRD)和扫描电子显微镜(SEM)研究了球磨机转速、球料比及球磨时间等工艺参数对生成物物相和显微形貌的影响,着重研究了机械合金化引起的Fe-Si合金相变过程。研究表明,随球磨时间的延长,合金粉末依次析出ε-FeSi、α-FeSi2和β-FeSi2相,随后β-FeSi2、α-FeSi2相消失,合金粉末转化为单一相ε-FeSi;在球磨机转速为450r/min、球料比为10∶1、球磨时间为35~50h时,所得合金粉末中β-FeSi2相的质量分数约为50%。 相似文献
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Ti—Fe二元系在机械合金化过程中的结构转变及纳米晶TiFe储氢合金的制备 总被引:7,自引:0,他引:7
研究了Ti-Fe和Ti-Fe-Mn纳米晶储氢合金的机械合金化制备,用X-ray衍射分析了Ti-Fe和Ti-Fe-Mn在高能球磨的机械合金化过程中的结构变化及获得的FeTi相的晶粒尺寸。此外,还考察了球磨条件包括气氛、球磨机转速等对球磨过程中结构变化的影响。研究结果表明:采用适当的球磨参数并辅以后续热处理,可以制备出不同晶粒尺寸的纳米晶储氢合金,在本研究中获得的FeTi合金的最小平均晶粒尺寸可达13nm。 相似文献
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为了研究球磨参数对ODS奥氏体不锈钢机械合金化效果的影响,以Fe、Cr、Ni、W、Ti纯金属元素粉末和纳米Y2O3为原料进行混合(配比为Fe-18Cr-8Ni-2W-1Ti-0.35Y2O3,质量分数),通过高能球磨的方式实现混合粉末的机械合金化.研究球磨时间、转速的变化对粉末粒度、成分均匀度和固溶程度的影响.结果表明,在真空环境下,球料比为10∶1、转速为380r/min、球磨时间60h时,粉末达到了很好的机械合金化效果,成分分布均匀;当球磨时间延长到100h时,粉末颗粒达到最细,继续球磨,粉末将出现明显的团聚.对最优机械合金化工艺参数获得的粉末进行热压致密化研究表明,随着温度的升高,试样的密度随之升高,维氏硬度随之降低. 相似文献
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球磨条件对Fe-Ni纳米晶结构和磁性的影响 总被引:7,自引:0,他引:7
用机械合金化方法制备两组Fe100-xNix系纳米晶合金。采用不同的球磨条件:A组样品的球粉质量比为20:1,球磨机的转速为200r/min,对应着较高的球磨能量。B组样品的球粉质量比为14:1,球磨机的转速为160r/min。对应着较低的球磨能量。在相同的球磨时间(60h),不同的球磨能量下得到Fe-Ni系纳米晶合金的不同结构与磁性。前者基本上为单相Ni(FCC)的无序Fe-Ni固溶体而后者为α-Fe(BCC)与γ-Ni(FCC)混相合金。前者基本呈现超顺磁性的磁滞回线而后者却出现了Perminvar效应,吴峰腰形磁滞回线。本文对这些结果进行了讨论。 相似文献
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研究了球磨时间对Y2O3氧化物弥散强化(ODS)镍基高温合金机械合金化和拉伸性能的影响.镍基高温合金采用机械合金化和热压烧结方法制备.镍基ODS高温合金粉末是在行星式球磨机上进行球磨.采用扫描电镜及X射线衍射分析了球磨时间对镍基ODS合金粉末形貌和物相的影响.研究结果表明,Y2O3氧化物弥散强化镍基高温合金机械合金化粉末尺寸随研磨时间的增加先增大后减小,8h粉末颗粒尺寸达到最大,之后粉末颗粒尺寸逐渐减小,28h后,镍基ODS合金粉末尺寸稳定且均匀.拉伸结果表明,采用研磨28h的合金粉末制备的镍基ODS合金具有最高的抗拉强度(1300MPa). 相似文献
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由于NiAl基金属间化合物的一些优异性能,长期以来作为高温结构的候选材料而得到了广泛的关注。本文中用机械合金化法合成了NiAl金属间化合物粉末,详细介绍了球磨工艺,对NiAl金属间化合物粉末的形貌和物相进行表征。结果表明,金属Ni和Al的粉末在球磨机内仅球磨5h就可以使大部分金属粉末转化为NiAl金属间化合物,随着球磨时间的延长,金属间化合物有细化的趋势。 相似文献
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《Materials Science & Technology》2013,29(10):1345-1350
AbstractUltrafine composite powders of W – 15 wt-%Cu, W – 25 wt-%Cu, and W – 35 wt-%Cu have been fabricated by mechanical alloying. The effects of type of mill, process control agent, temperature of milling, and ball/powder ratio on the final products have been evaluated. The results show that the planetary ball mill possesses a higher impact energy intensity than that of the vibratory ball mill. The optimum milling time is confirmed by the formation of a nanocrystalline microstructure in the planetary ball mill after optimisation of the milling parameters. A steady state between cold welding and fracture is attained with a milling time of up to 25 h in the planetary ball mill under optimised conditions. Crystallites with sizes of 7 – 8 nm for W – Cu composite powders have been obtained after 25 h of ball milling. The powders obtained after mechanical alloying have been characterised in terms of their size, shape, phase constitution, and microstructural features using X-ray diffraction and scanning electron microscopy. 相似文献
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One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container
and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled
material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical
reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography
and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and
vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for
prevention of Fe contamination. 相似文献
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Elemental powder mixtures of 50Ti-50Al (at.%) were mechanically alloyed via various ball milling methods. The microstructural evolution during the milling indicates that the mechanical alloying behavior is strongly affected by milling methods, and horizontal ball milling is most effective for producing homogeneous metastable powders. The mechanically alloyed powders were consolidated by vacuum hot pressing followed by homogeneous annealing. Compression testing results showed that the annealed specimens still retain fine grains and have a good combination of fracture strength and ductility, as compared to cast specimens of the same alloy. 相似文献
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Ksenia Zhuravleva Sergio Scudino Mohsen Samadi Khoshkhoo Annett Gebert Mariana Calin Ludwig Schultz Jürgen Eckert 《Advanced Engineering Materials》2013,15(4):262-268
β‐Type Ti–Nb powders which are needed as precursors for porous implant materials were produced by mechanical alloying of elemental powders. The effect of different fractions of the inorganic milling agent NaCl on the phase reactions during the milling process was investigated by means of X‐ray diffraction and scanning and transmission electron microscopy. It was demonstrated, that addition of ≥2 wt% NaCl during continuous ball milling is efficient for establishing a nanostructured β‐phase alloy and for the achievement of high powder yield. 相似文献
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研究了球磨时间、固液比、料球比和磨球尺寸与级配对太阳能电池银浆用玻璃粉粒度及形貌的影响,并将其与一定比例的银粉、有机载体配制成导电银浆,印刷、烧结在硅片上形成晶体硅太阳能电池片,测试了其电学性能。实验结果表明,将玻璃粉用作正面银浆粘接剂时,其最佳的行星球磨工艺参数:球磨时间为4h,固液质量比为1∶0.8,料球质量比为2.5∶1,磨球级配w(大)∶w(中)∶w(小)为3∶2∶1。此时,制备的多晶硅太阳能电池串联电阻为7.15mΩ,光电转换效率可达16.56%。 相似文献
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J. B. Fogagnolo M. H. Robert E. M. Ruiz-navas J. M. Torralba 《Journal of Materials Science》2002,37(21):4603-4607
Mechanical alloying has come to the fore in fields such as the production of intermetallic compounds, supersaturated solid solutions, amorphous materials and metal matrix composites. With this process, composite powders are obtained with characteristics that are impossible to achieve employing conventional powder metallurgy techniques. In this work, aluminium powder AA6061 is mixed with silicon and aluminium nitrides in a conventional mixer and in a high-energy ball mill to obtain composite powders that are subsequently uniaxially cold pressed and hot extruded. The necessary pressure to extrude the composite cold pressed powders varies with the powder condition, being lower for the composite powder conventionally mixed, higher for the composite powder after a short time of milling, and intermediate after a longer time of milling, due to the morphological and structural changes typical of the mechanical alloying process. 相似文献