共查询到20条相似文献,搜索用时 203 毫秒
1.
2.
3.
4.
以Ag、Sb、Te单质粉体为原料,采用机械合金化工艺制备了单相的AgSbTe2化合物粉体。系统研究了机械合金化工艺制度,包括球料比、转速、球磨时间对粉体相组成、颗粒尺寸的影响。结果表明,在球料比为20∶1、转速大于400rpm、球磨时间大于15h时,可得到单相AgSbTe2化合物粉体;当球料比为20∶1、转速为600rpm、球磨48h后,可得到平均粒径约370nm单相AgSbTe2化合物粉体,其表面小颗粒尺寸约为50~100nm。 相似文献
5.
6.
纳米晶SmCo5粉体具有高矫顽力和强磁耦合的优点,是制备纳米复合永磁材料使用最广泛的硬磁材料之一。采用表面活性剂辅助球磨法制备SmCo5微纳米片,采用行星式球磨机,系统研究了球磨时间、球料比和表面活性剂含量对SmCo5粉体的形貌和磁性能的影响。结果表明随着球磨时间和球料比的增加,SmCo5粉末的粒径和厚度减小并转化为微、纳米片,当球磨时间和球料比大于4 h和12∶1后,SmCo5粉末的粒径和厚度变化不明显。选用球料比16∶1、球磨时间2 h、表面活性剂含量30%参数,SmCo5粉体具有最优的磁性能,剩磁(Mr)为45.9 Am2/kg,矫顽力(Hc)为1.13×106 A/m。 相似文献
7.
8.
采用高能球磨对合成一维β-SiC纳米材料的原料-Si粉和SiO2粉分别进行处理。通过正交试验研究球磨转速、时间、球料比、级配比等因素对球磨后粉体粒径的影响规律,结果表明,Si粉的球磨优化工艺为转速300r/min、球磨时间4h、球料比5:1,级配比φ20 mm:φ10 mm:φ6mm:φ2mm=1:50:180:400;SiO2粉的球磨优化工艺为转速350 r/min、球磨时间4.4 h、球料比15:1,级配比φ20mm:φ10mm:φ6mm:φ2mm=1:50:180:400。借助粒度分析仪及透射电子显微镜(TEM)对产物进行表征,发现经过球磨处理后的粉体粒度分布均匀,比表面积提高,可用以合成高质量的一维β-SiC纳米材料。 相似文献
9.
以节约粘土资源及开发新型建筑材料为目的,利用长江沿岸低品位石英砂开发研制保温隔热砖。研究了球磨工艺对低品位石英砂细化效果的影响,为制备高性能保温隔热砖奠定了原料基础。结果表明,随着球磨时间的延长,石英砂粉体平均粒径逐渐减小,粒度分布逐渐变窄;随着球磨转速的增加,石英砂粉体平均粒径逐渐减小,粒度分布逐渐变窄;随着球磨装料量的增多,石英砂平均粒径逐渐变大,粒度分布逐渐变宽。综合整个工艺和性能考虑,确定石英砂球磨工艺为球磨时间60min、球磨转速300r/min、球磨机装料量200g/L。 相似文献
10.
采用正交实验和单因素实验相结合的方法,研究了球磨工艺参数(包括粉体质量分数、球磨机转速、球磨时间、球料比和球配比)对微细La2O3水悬浮液分散性的影响及其作用机理,获得了优化后的球磨工艺参数,据此制备出的悬浮液的粉体分散率高达97.88%。粒度测试结果表明采用优化的工艺参数球磨后得到的La2O3颗粒更加细小,分布更加均匀,计算出单个粒径为6μm的La2O3颗粒经过球磨后可以得到球径为1.5μm的颗粒数与球径为0.25μm的颗粒数之比约为1∶195。根据Stokes定律和爱因斯坦方程获得了微细La2O3颗粒沉降位移及扩散位移与其粒度间的函数曲线,从而揭示出采用优化球磨工艺参数球磨后微细La2O3水悬浮液的高分散机理。 相似文献
11.
热喷涂球磨法制备超细铜锌粉 总被引:3,自引:0,他引:3
本文将热喷涂法与机械球磨法相结合,提出一种新的超细铜锌粉末的制备方法.讨论了热喷涂工艺参数、球磨时间、球磨助剂、热处理条件对粉末性质的影响,并采用扫描电镜法、X射线衍射法、筛分法对粉末的粒度、形貌、成分等进行了分析,得出最佳工艺参数.该方法可以制备出粒度分布均匀、性质稳定、粒度为200~500nm的超细铜锌粉末. 相似文献
12.
13.
14.
The synthesis of ultrafine zinc oxide powders using the combination of precipitation and mechanical milling followed by subsequent heat treatment was investigated. Zinc hydroxide/oxidehydrate precursor was prepared by precipitation process using zinc chloride as the starting material. Sodium chloride was added to avoid agglomeration during the mechanical milling process. Zinc oxide particles were formed in the NaCl matrix after heat treatment and obtained after removal of NaCl. The size and structure of zinc oxide powders were studied using X-ray diffraction, transmission electron microscopy, and BET surface area measurements and thermal analysis. This has shown that the particle size of zinc oxide powder is strongly dependent on the weight ratio of sodium chloride and precursor. ZnO particles with an average primary particle size of 15 nm could be obtained when the NaCl/precursor weight ratio was 4 : 1 or above. 相似文献
15.
在氩气条件下以400r/min高能球磨镁合金粉末,并将球磨后的粉末经过冷压—热压烧结—热挤压成型。研究了不同球磨时间的粉末以及挤压态样品的微观组织和力学性能。结果表明:随着球磨时间的延长,粉末颗粒尺寸可以细化到8μm,晶粒尺寸有效细化到34nm,在整个球磨过程中粉末有一定程度的氧化,并伴随有MgO纳米颗粒产生。粉末经过热压烧结—热挤压成型后,材料内部有MgZn2相颗粒析出,且均匀分布于Mg基体中。随着粉末颗粒的细化,材料性能得到改善,当球磨至10h时,粉末挤压态样品的极限拉伸强度为365 MPa,压缩屈服强度高达325 MPa,极限压缩强度保持在466 MPa。球磨至25h,颗粒平均尺寸细化至8μm左右,使得颗粒表面能大幅度增大,颗粒表面的氧化膜增厚,在热压烧结过程中阻碍了颗粒之间的结合,进而使得材料的力学性能恶化。 相似文献
16.
For biomedical applications drug carrying polymers are coated around magnetic iron oxide particles to form microspheres. In the present study, the iron oxide powder was ball milled. Microspheres were then synthesized by solvent evaporation, resulting in iron oxide particles encapsulated in a polymer and drug coating. Various parameters, such as the duration of milling and agitation speed as well as the polymer concentration were varied. A milling time of 72 h was found to yield a small size and narrow size distribution of particles; the average particle size was about 600 nm. Measurements of the change in grain size and the magnetic properties of the powder with milling time were performed. It was determined that the size of the microspheres was not sensitive to the initial particle size, but it could be decreased by variation of agitation speed or polymer concentration. The agitation speed and polymer concentration of 400 rpm and 0.04 g poly(l-lactic acid) in 8 g dicholoromethane, respectively, was found to yield small, spherical microspheres with a narrow size distribution. The surface morphology and magnetic properties of the microspheres was also analyzed. 相似文献
17.
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
18.
19.
Fusheng Sun Paula Rojas Alejandro Zúiga Enrique J. Lavernia 《Materials Science and Engineering: A》2006,430(1-2):90-97
A nanocrystalline Ti alloy with a uniform distribution of grains was synthesized using cryogenic mechanical milling. The effects of cryomilling parameters, such as milling time and ball to powder ratio (BPR), on the particle size, grain size, chemistry, and structure of cryomilled Ti powders were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental results show that nanocrystalline Ti powders with a grain size of about 20 nm can be prepared using the cryomilling technique. Compared to SPEX milling at room temperature, cryomilling led to lower contamination levels of oxygen, nitrogen, and iron in the cryomilled Ti powder. The average particle size initially increased from the original 55 μm to a maximum value of 125 μm after 2 h of milling, and then decreased to 44 μm after 8 h of milling. Both the average particle size and the grain size decreased as the BPR increased. 相似文献
20.
A model of high-energy ball milling of powders has been proposed. It is demonstrated that part of the energy is consumed for initiation of microstrains ε during milling and, hence, the process of the powder grinding is decelerated. An analytical expression has been deduced describing the size of nanocrystalline powder particles as a function of the milling time. The model and the experiment have been compared, using a powder of tungsten carbide (WC). The average size of the particles and the value of the microstrains in the ball-milled powder were determined by an x-ray method from broadening of diffraction reflections. The size of the particles was also evaluated using scanning electron microscopy and the sedimentation method. 相似文献