高能球磨法制备BaTiO3陶瓷

用高能球磨方法对BaO和TiO2混合粉末进行了机械力化学合成BaTiO3前驱体的试验研究,并借助于高分辨率透射电镜(HRTEM)进行了该前驱体的烧结性能研究。试验结果表明,随着球磨过程的进行,物料很快细化,随后发生晶体结构的变化。球磨30h后的X射线粉末衍射仪(XRD)图谱中发现了BaTiO3;球磨50h后,BaTiO3的特征峰相当明显。HRTEM测定结果证明,机械力化学活化的BaTiO3前驱体在1200℃下即可获得晶体发育完善、结构致密的烧结体。所得的烧结体的孔隙率达4.95%,平均孔径为50nm,体积密度达到其理论密度的95%左右,且具有较高的力学性能,抗折强度达500MPa以上。     

高能球磨法制备超细叶腊石粉体的研究

以浙江青田叶腊石为原料。利用高能球磨法制备超细粉体。以粒径为衡量指标,优化制备工艺,并对其物相和表面形貌进行了分析。结果表明：高能球磨过程中,球料比、球磨转速、球磨时间以及浆料比对最终超细粉体粒径影响显著。通过物相和表面形貌分析,高能球磨使得叶腊石粉体的粒径减小,形状改变和发生团聚。这可能将赋予粉体特殊的性能,拓宽叶腊石的应用领域。     

高能球磨活化硬化水泥浆体的研究

研究了硬化水泥浆体的高能球磨机械力化学活化，借助于XRD、SEM和DTA等，测定了硬化水泥浆体的结构和力学性能随球磨时间的变化。试验结果表明，在球磨过程中．强烈的机械力作用首先使水泥石中的各水化物发生脱水作用。DTA测定结果证明，脱水程度随球磨时间的而增大，球磨至60min时，Ca(OH)2已完全脱水；同时，脱水温度随球磨时间而降低。进一步球磨使水化物的晶体结构发生严重的畸变和破坏，最终成为无定形态物质。球磨80min后粉体净浆的3d和28d抗压强度分别达28，33MPa和38．85MPa，说明硬化水泥浆体经高能球磨机械力活化后可重新作为胶凝材料使用。     

高能球磨制备430L不锈钢纳米晶粉末

采用XRD、MS2000粒度分析仪和SEM对430L粉末在高能球磨中的晶粒尺寸、粒度和形貌演变进行了研究.结果表明:高能球磨可制备430L纳米晶粉末,球料比一定,随着球磨时间的延长,晶粒尺寸逐渐减小,且球磨初期,晶粒尺寸减小最快,其后延长球磨时间,晶粒尺寸缓慢减小;在高能球磨中,冷焊、断裂和加工硬化现象始终存在;430L粉末粒度的演变依次经历了快速增大、快速减小、基本保持不变和缓慢减小四个阶段.初步确定了制备430L纳米晶粉末的合理球磨时间约为20～30 h.     

在氮气中球磨Ti粉制备纳米TiNx

采用Spex型振动式高能球磨机在氮气中球磨Ti粉,采用X射线衍射和扫描电镜分析产物的相结构和形貌.结果表明,Ti粉在氮气中球磨9h,可完全转变为fcc结构TiNx纳米粉.     

Preparation and Characterization of Nano structured Materials from Fly Ash: A Waste from Thermal Power Stations, by High Energy Ball Milling

The Class F fly ash has been subjected to high energy ball milling and has been converted into nanostructured material. The nano structured fly ash has been characterized for its particle size by using particle size analyzer, specific surface area with the help of BET surface area apparatus, structure by X-ray diffraction studies and FTIR, SEM and TEM have been used to study particle aggregation and shape of the particles. On ball milling, the particle size got reduced from 60 μm to 148 nm by 405 times and the surface area increased from 0.249 m²/gm to 25.53 m²/gm i.e. by more than 100%. Measurement of surface free energy as well as work of adhesion found that it increased with increased duration of ball milling. The crystallite was reduced from 36.22 nm to 23.01 nm for quartz and from 33.72 nm to 16.38 nm for mullite during ball milling to 60 h. % crystallinity reduced from 35% to 16% during 60 h of ball milling because of destruction of quartz and hematite crystals and the nano structured fly ash is found to be more amorphous. Surface of the nano structured fly ash has become more active as is evident from the FTIR studies. Morphological studies revealed that the surface of the nano structured fly ash is more uneven and rough and shape is irregular, as compared to fresh fly ash which are mostly spherical in shape.     

高速振动球磨对MoS_2/TiO_2纳米微粒的润滑与光催化性能的影响

将硫代乙酰胺和钼酸钠在酸性条件下的反应产物Mo S_3沉积在Ti O_2表面上,在不同煅烧温度以及N_2保护气氛下煅烧脱硫后得到纳米Mo S_2/Ti O_2。制备的纳米Mo S_2/Ti O_2经高速振动球磨后分别被用作润滑剂或催化剂,然后考查了球磨时间与煅烧温度对纳米Mo S_2/Ti O_2的润滑和催化性能的影响。结果表明:高速振动球磨可以改善纳米Mo S_2/Ti O_2的润滑性能,随着球磨时间的延长,纳米Mo S_2/Ti O_2的光催化性能也有所提高;较低的煅烧温度有利于改善Mo S_2/Ti O_2的润滑性能与光催化性能;经高速振动球磨之后,纳米Mo S_2/Ti O_2球形微粒出现破碎而导致结构、性质改变,从而对其润滑与光催化性能产生一定的影响。     

Preparation of Sn-Si-C Composite as Li-ion Battery Anode Material by High Energy Ball Milling and Its Properties

Electrochemically active Sn-Si-C composite was synthesized by high energy ball milling(HEBM) in Ar atmosphere.The so-obtained composite was characterized by X-ray diffraction and field emission scanning electron microscopy.Lithium insertion/extraction characteristics of the composites were examined by constant current charge-discharge and cyclic voltammetry methods.The results show that there is no new alloy generated by HEBM.The composite synthesized by two-step HEBM resulted in initial lithium insertion s...     

高能球磨时间对MgNb2O6陶瓷显微结构和微波介电性能的影响

采用高能球磨法制备粉体,研究了粉体球磨时间对MgNb2O6陶瓷显微结构和微波介电性能的影响,结果表明,1180℃烧结陶瓷,随球磨时间增加,平均粒径减小,气孔率降低,相对密度增大,介电常数增大;升高烧结温度到1220℃以上,不同球磨时间制备陶瓷样品相对密度达到95.8％以上,平均晶粒尺寸3.5m,εr为19.7,而Qxf值随球磨时间先增大后减小.高能球磨制备粉体能有效促进MgNb2O6陶瓷在1220℃下中温烧结,且具有优良的微波介电性能(εr=19.7,Q×f=28 744 GHz),有望成为新一代中温烧结高频微波介质基板材料.     

光催化纳米TiO2的低温液相制备及表征

以工业钛液为原料,通过低温液相法可以直接得到锐钛型纳米二氧化钛粉体.用X射线衍射(XRD)、高分辨率透射电子显微镜(HRTEM)、透射电子显微镜(TEM)、原子力显微镜(AFM)、激光粒度仪(LS)和N2-吸附脱附技术研究了制备的纳米TiO2粉体的晶型、形貌、晶粒尺寸、粒径分布及比表面积.在紫外光照下对哑甲基蓝的降解,评价了溶胶的光催化活性.结果表明,在低温下制备出结晶良好、细小品粒尺寸、高比表面积、分散性好的锐钛型纳米TiO2粉体粒子,且制备的TiO2溶胶显示出好的光催化活性.     

Effects of Bi2Se3 Amount in Thermoelectric Performance of Bi2(TeSe)3 Materials Fabricated by High‐Energy Ball Milling

Amount of Bi₂Se₃ has significant role in controlling thermoelectric properties of n‐type Bi₂(TeSe)₃ material. In this study, effects of Se alloying amount in Bi₂(TeSe)₃ thermoelectric materials fabricated by high‐energy ball milling and spark plasma sintering were studied and compared with other fabrication methods. Amount of Bi₂Se₃ (5%, 10%, 15%, and 20%) did not have any significant effect over fabricated powder size, grains of consolidated bulks, and mechanical properties; however, electrical properties and thermoelectric efficiency were noticeably influenced. Both carrier concentration and carrier mobility decreased with increase in Se amount. In total, 20% Se alloying was effective in improving thermoelectric figure of merit ZT value by almost 40% compared with only 5% Se alloying.     

片状锌粉的高能球磨制备工艺及其市场应用

介绍了片状锌粉的主要制备工艺、产品规格与分析测试技术,并对片状锌粉的产品应用领域进行了探讨。     

微生物球磨制备微粉化粉煤灰及其对天然橡胶补强性能的研究

先将粉煤灰进行微生物腐蚀处理,然后通过球磨工艺制备微粉化粉煤灰,球磨20 min即可将粉煤灰的平均粒径由约1 250 nm高效减小至约194 nm,比相同条件下直接球磨得到的粉煤灰平均粒径（504 nm）大幅减小。微生物改性粉煤灰即使经过球磨后其表面仍附着有亲水亲油性的生物膜,这有利于提高其与有机材料界面相容性。微粉化粉煤灰/炭黑并用的天然橡胶（NR）复合材料的拉伸强度可达24.6 MPa,与单纯炭黑补强的NR复合材料相当。扫描电子显微镜照片显示经微生物和球磨处理的微粉化粉煤灰与NR的相容性大幅改善。     

直接氧化法制备TiO2-Al2TiO5复相陶瓷

以Ti—Al—C和TiC—Ti—Al体系为反应体系,采用直接氧化法制备Al2TiO3-TiO2复相陶瓷。研究了氧化温度对体系合成产物组成的影响。结果表明,两种体系的合成产物都由Al2TiO3和TiO2相组成,没有杂质相存在。碳高温氧化成CO2向外扩散,在坯体内形成疏松通道,利于O2的渗入,提高了氧化反应程度。     

微波诱导燃烧法制备稀土离子掺杂氧化锌纳米材料

以尿素为燃料,硝酸锌作为锌源和氧化剂,硝酸铕提供掺杂离子,以微波诱导燃烧法合成了铕掺杂氧化锌纳米材料.并考察了尿素用量、微波功率、稀土离子掺杂量对产物性能的影响.采用XRD,SEM,PL等测试方法对产物进行了表征.实验结果表明:当微波功率为340 W,燃料恰好完全反应,反应物硝酸锌与硝酸铕物质的量之比为1∶1时得到产品的结晶度高,光学性能最好;根据谢乐公式计算一次粒子平均粒径约为50 nm,晶相与标准立方相氧化锌衍射峰非常吻合.PL测试结果表明,362 nm处出现的紫外发射峰是由于氧化锌的紫外发射峰发生蓝移造成,而451 nm、468 nm、482 nm处的蓝光发射峰可能是由于氧空位形成的浅施主能级向价带跃迁引起的.     

溶胶-凝胶法合成的TiO2和Fe、Zn和Si掺杂TiO2 纳米粉体的光催化研究

利用溶胶-凝胶法合成了纳米尺寸的TiO2和Fe,Zn和Si掺杂的TiO2纳米粉并进行了粉体微观结构和晶体结构的表征.通过纳米粉对甲基橙的分解研究了合成粉体的光催化特性.溶胶-凝胶法制得的TiO2纳米粉具有比商业TiO2高的光催化活性但掺杂5%Fe,Zn或Si却没有带来TiO2的光催化活性的提高.     

球磨法制备高导电聚酰亚胺/石墨烯复合材料

分别采用球磨和超声混合两种分散方法,制备聚酰亚胺(PI)/石墨烯(GNPs)复合材料。利用原子力显微镜、拉曼光谱、扫描电子显微镜、透射电子显微镜对其微观结构和形貌进行表征,研究了复合材料的电导率。结果表明,与超声混合法相比,球磨法制备的复合材料,GNPs均匀地包覆在PI颗粒表面,热压成型后形成更为完整的导电网络结构。GNPs质量分数为0.5%时就达到逾渗阈值;当GNPs质量分数为3%时,电导率到达最优值为1.94×10–2S/m。     

Effect of Silicon Additions on Structural and Microstructural Properties of Nanostructured FeCoNi Alloy Prepared by High-Energy Ball Milling

Silicon - Full use of experimental measurements obtained by the mean of the X-ray diffraction technique and the Rietveld refinement has been implemented to study the effects of the addition of Si...     

Characterization of Nano-SiC Powder Prepared by High-Energy Ball Milling as a Mechanochemical Process with Subsequent Annealing Process

Glass Physics and Chemistry - SiC nano-powder compound was prepared by mechanochemical process followed by annealing. Phase evaluation and microstructural changes of the powders during the...     

高能量密度材料

简述国外高能量密度材料研究计划及其在推进剂，炸药等领域的军事应用进展。