共查询到19条相似文献,搜索用时 46 毫秒
1.
Fe-Cu二元互不溶体系合金在机械合金化过程中形成纳米晶过饱和固溶体,并显示出与其微米尺度结构合金所不同的独特性能。综述了近年来Fe-Cu二元互不溶体系中纳米晶过饱和固溶体的机械合金化研究进展,着重介绍了Fe-Cu纳米晶过饱和固溶体的形成机理及其力学和物理性能等。 相似文献
2.
3.
机械合金化制备纳米晶硬质合金粉的进展 总被引:2,自引:0,他引:2
综述了机械合金化制备纳米晶硬质合金粉的概况、原理和两种用该方法制备纳米晶硬质合金粉的方式。并分析了各工艺参数对机械合金化制备纳米晶硬质合金粉的影响。该技术工艺简单,可实现工业化生产,是一种很有应用前途的方法。 相似文献
4.
5.
机械合金化纳米晶材料研究进展 总被引:17,自引:0,他引:17
综述了机械合金化制备纳米晶材料的研究进展,重点介绍了高强度铝合金,铜合金,难熔金属化合物,金属储氢材料,复相烯土永磁材料等几类机械合金化纳米晶材料的制备与组织性能,指出了机械合金化技术在纳米晶材料制备方面的优势及应用前景。 相似文献
6.
采用热机械合金化制备纳米晶W-Cu复合粉末。通过XRD、SEM、激光粒度测试等方法对球磨后的粉末进行表征。结果表明:随球磨时间延长,W的晶粒尺寸不断减小,球磨30 h后W的平均晶粒尺寸为41 nm左右;球磨初期,粉末迅速细化;随球磨时间延长,粉末粒度有所增加;进一步增加球磨时间,粉末粒度减小。球磨粉末还原后有较高的烧结活性,1 200℃烧结后相对密度可达97%以上。烧结材料的组织非常均匀,且晶粒细小。 相似文献
7.
用机械合金化方法制备了镍基固溶体粉末,探讨了机械合金化球磨工艺对镍基混合粉末粒度的影响,在以酒精为过程控制剂,转速为180r/min,球磨时间为20h,球料比为40:1(质量比)时,可获得粒度约为3μm的镍基合金粉末. 相似文献
8.
9.
机械合金化制备超细、纳米晶CuCr触头材料的探讨 总被引:2,自引:0,他引:2
分析探讨了机械合金化工艺制备超细、纳米晶CuCr材料中的晶粒尺寸、氧含量和材料密度控制等主要问题,提出了一种低成本制备高性能CuCr触头材料的新思路,即添加高性能晶粒长大抑制剂 普通真空烧结工艺。 相似文献
10.
11.
12.
采用溶胶-喷雾干燥-煅烧-氢还原方法制备了纳米Mo-Cu复合粉末。综合利用XRD、TEM和EDX等检测方法对该Mo-Cu复合粉末的相结构特征和粉末体的烧结机制进行了分析。结果说明:纳米Mo-Cu复合粉末由Mo(Cu)和Cu(Mo)超饱和固溶体组成,但该Mo(Cu)和Cu(Mo)超饱和固溶体呈不稳定状态,随烧结温度升高和保温时间延长,固相Mo(Cu)中析出的Cu逐渐溶解于液相Cu(Mo)中,而液相Cu(Mo)中的Mo逐渐析出沉积在固相Mo(Cu)颗粒上,此过程促进了烧结体致密化。 相似文献
13.
AbstractOrdered B2-NiAl intermetallic compound powder was successfully synthesised by mechanical alloying after 20 h in an attritor mill, starting from elemental Ni and Al powders and without subsequent heat treatment. NiAl powder obtained was homogenous and had a nanocrystalline microstructure. It was consolidated by field assisted hot pressing (FAHP), in a novel configuration with a Gleeble 3800 thermomechanical simulator. The powder was also processed by hot isostatic pressing (HIP) in order to compare both methods. The consolidation was successful by both methods obtaining above 98% of NiAl theoretical density (5·86 g cm?3). The results showed that the consolidation process by FAHP technique is effective and uniform throughout the sample as indicated by homogenous hardness values, obtaining microstructure and properties similar to those obtained with HIP technique, with certain advantages over it. The achieved room temperature yield strength of 850 MPa and fracture strain 26–28% corresponds to the bulk values of NiAl intermetallic. 相似文献
14.
15.
16.
Precipitation of carbides from supersaturated niobium-carbon solid solutions has been measured using electrical resistance and transmission electron microscopy. The process is shown to follow a rate law of the form 1 -w = exp (-t/τ) n with values ofn around 0.6. The activation energy is consistent with diffusion of carbon as the major rate controlling factor. Transmission electron micrographs of samples aged in the time and temperature range of resistance measurements (days at 180°C to seconds at 400°C) fail to show any visible precipitate. However, foils aged at 400°C for much longer times show very distinct platelike precipitates. On the basis of this then value is taken to signify carbon segregation to solute-rich regions on certain planes which later develop into well defined plates. 相似文献
17.
18.
19.
在Ar气氛下用机械球磨方法制备了Ni-30%Fe(质量分数)纳米晶固溶体粉末,用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、电子探针(EPMA)、差热分析(DSC)等方法观察和分析了Ni-30%Fe(质量分数)粉末机械球磨过程中微观组织演变及相变过程。结果表明,在球磨初始阶段粉末颗粒呈现出粗大片层组织,随球磨进行演变为细小片层结构。球磨至25h,形成了晶粒尺寸为10nm的Ni基固溶体。DSC的结果表明在1444.2℃出现固相-液相转变。 相似文献