SPEX BM-450高能量球磨机/球磨仪/研磨仪（原8000D）

机械合金化条件对储氢材料Mg63Ni30Y7微观结构和电化学特性的影响

在可充电电池应用领域，金属间化合物Mg2Ni（形成Mg2NiH4氢化物）可作为一种储氢材料而受到越来越大的关注。理论上讲，H元素质量分数占到Mg2NiH4氢化物的3.6%，其电池放电能力应达到1000mAh/g，但实际上只有8mAh/g，这主要是Mg2Ni晶粒表层快速形成的氢化物层严重阻碍了氢原子扩散。而通过机械合金化的方法制备非晶态和纳米晶粉末可以极大提高氢扩散能力，增强其氢化—去氢化反应动力。文章以Mg2Ni和稀土金属Y为实验材料，在不同机械合金化条件下，包括不同的研磨机类型、研磨周期、研磨温度等，研究了合金化粉末的化学成分、微观结构和形态、热稳定性以及电特性等。结果显示：采用SPEX 8000系列高能研磨机制备的合金化粉末具备纳米晶相—非晶相相间的微观结构，阳极极化曲线显示出更高电流密度13-18mA/g，充放电测试曲线显示出具备更高的最大放电能力247mAh/g，所需研磨周期更短（第二个循环），且无需液氮冷冻辅助研磨；而Retsch PM 4000行星式研磨机制备的合金化粉末主要由非晶相组成，无纳米晶生成，阳极极化曲线显示其电流密度仅为3mA/g，需要更长的研磨周期（第五个循环）获得最大的放电能力216mAh/g，且每个周期间隔需要对研磨罐进行液氮冷却处理。

SPEX 8000和Fritsch Puverisette-6球磨机机械化学反应效率的量化对比

通过对比Zn和S粉末在不同研磨条件下（SPEX 8000系列三维球磨仪+平底研磨罐、SPEX 8000三维球磨仪+圆底研磨罐、Fritsch Puverisette-6行星式球磨仪）的自蔓延反应的着火时间，并绘制出研磨反应物在不同球料比条件下的自蔓延着火时间关系曲线，得出不同球磨仪机械化学反应效率量化关系：相同的研磨条件下，反应物着火时间与球料比之间呈线性分布；分别计算其线性斜率得出SPEX 8000系列三维球磨仪+平底研磨罐具有最高的研磨效率140p（min），是Fritsch Puverisette-6行星式球磨仪研磨效率的350p（min）/140p（min）=2.5倍；同时指出反应物自蔓延着火效率等同于机械化学渐进反应过程中金属或氧化物无序化过程中所需的能量输入，即研磨连续能量输入。

行星式（Fritsch P7）和振动式(Spex 8000)高能球磨机制备Fe(Nb,Zr)合金的微观结构和磁性行为对比

通过两种不同运动方式的高能球磨机（行星式和振动式）制备出Fe80Nb7B12Cu1和Fe80(NiZr)7B12Cu1两种纳米晶合金。分别通过X射线衍射（XRD）、差热热重分析（DSC）、振动磁强计（VSM）等手段测定研磨粉末的微观结构、热效应和磁性行为。相对来讲，研磨方式的不同会影响最终产物的微观结构和性能。结果显示：生成的两种纳米晶合金的主要相是体心立方结构的Fe基固溶体，且振动式高能球磨带来更高的能量输入；通过SPEX 8000振动式高能球磨机制备的Fe80Nb7B12Cu1纳米合金发现次生Nb(B)相，而Fritsch P7行星式球磨机制备的Fe80(NiZr)7B12Cu1只观察到了少量的Zr基次生相；纳米晶晶粒尺寸为9.5-15.1nm，次生相则对应着更低的晶粒尺寸；室温下测量矫顽力值在28.6—36.9Oe。

美研究人员研发出全新高熵合金,强度高于钛合金

导读：来自美国北卡罗莱纳州立大学和卡塔尔大学的研究人员合作，日前研发了全新高熵合金，该材料拥有更高的强度重量比，目前任何一种金属都不具备这样的优越性能。研究人员利用机械合金法融合锂、镁、钛、铝和钪来打造低密度纳米晶合金(Al20Li20Mg10Sc20Ti30)，预估的材料强度重量比要明显高出其它纳米晶合金，甚至可以与陶瓷相媲美。

8000M机械合金自蔓延燃烧反应-都柏林三一学院(爱尔兰)

Mechanically-induced combustion reactions were carried out in a transparent quartz vial. The combustion processes were followed by high-speed video recording and optical pyrometers. Depending on the vial dynamics, the powder particles were seen to gather in a periodic collective motion, behaving like a granular gas characterised by subsequent changes in its density. After ignition, a considerable increase of brightness was observed, due to the extremely rapid propagation of the high-temperature reaction to the whole mass of powder. Experimental observations ?nd a very good correlation if compared to the results of numerical calculations simulating the particle system dynamics. Balls and powder dynamics were reproduced according to a well-known visco-elastic force scheme, while chemical conversion of each powder particle was described by a conventional nucleation-and-growth kinetics. The propagation mechanism of the reaction was studied and related to the dynamic features of the whole system.

Al2O3 -WC合成的高能球磨反应-圣保罗大学(巴西)

Like most carbide-based composites, the two main characteristics of alumina–tungsten carbide (Al2O3–WC) composites are high hardness and high wear resistance. These features confer the composites important engineering applications, in particular when they are used as cutting tools. The present research involved a study of Al2O3–WC nanometric powders obtained through reactive milling. In this process, high-energy milling promotes the reaction in a mixture of reactive powders. The material was milled in a high-energy SPEX 8000 Mixer/Mill, using WO3,Al and C precursor powders. The highly exothermic self-propagating high-temperature synthesis (SHS) type reaction was self-sustained, producing a temperature peak that was detected by a thermocouple attached to the external surface of the vessel. Using stoichiometric proportions of the reagents to reduce theWO3 and to obtainWC, and adding Al2O3 as diluent, the SHS reaction occurred up to a limit of 0.8mols of diluent, forming not only alumina but also aW2C mixture with littleWC. To obtain onlyWC it was required the addition of more than 0.8mols of C, which indicates that the reaction may have occurred through a gaseous phase reaction mechanism.

MgNi型储氢合金的机械合金化的电化学研究-华中科技大学(中国)

The electrochemical properties of amorphous MgNi-based hydrogen storage alloys synthesized by mechanical alloying MA were evaluated. The results show that these amorphous Mg Ni alloys exhibit a higher discharge capacity and relatively good rate capacity at 50 50 a suitable grinding time while their cycle life is very poor. In order to improve the cycle life, the surface of the amorphous Mg Ni 50 50 alloy was coated with Ti, Al and Zr in Spex 8000 millrmixer and the coating effects were further investigated. Based on experimental results, two kinds of MgNi-based amorphous alloys are designed by substituting part of Mg in MgNi-based alloys by suitable elements. These alloys are then composed of four components. Thus, the cycle life of electrodes consisting of these quaternary amorphous alloys is greatly improved. q2000 Elsevier Science S.A. All rights reserved.

Mg和Ni机械合金化过程中的显微组织演变-加州大学(美国)

This study investigates the microstructural evolution during mechanical alloying of Mg and Ni, and during subsequent heat treatments of SPEX milled powders. The milling was performed under an inert argon atmosphere, employing two different ball-to-powder ratios (BPR): 10:1 and 20:1. It was observed that a large number of defects were produced during the ?rst hours of milling. These defects led to the amorphi- zation of part of the system, and promoted an extensive re?nement of the microstructure as well. Later on, the formation of the Mg2Ni compound due to the crystallization of the amorphous phase was observed. The microstructural details showed us that a possible complete sequence of phase transformations during milling of pure Mg and Ni could be: Mgc +Nic →Mgnc +Nic →amorphous + Ninc +Mgnc →amorphous +Ninc +Mg2Ninc →Mg2Ninc, where c and nc stand for crystalline and nanocrystalline, respectively. On the other hand, subsequent heat treatments of the milled powder showed that the amorphous phase could also be transformed into Mg2Ni by heating. Finally, the knowledge of the evolution of the microstructure during milling and annealing were combined to propose an optimal processing route to ef?ciently obtain the Mg2Ni compound.

用机械合金化方法制备Ni-Al系金属间化合物

用球磨机分别对Ni-50at.-%Al和Ni-25at.-%Al混合粉末进行机械合金化，并对Ni3Al预合金粉末进行高能球磨，观察了粉末的金相组织，测定了粉末的硬度、平均直径和晶粒尺寸，并作了XRD物相分析。结果表明，经3h研磨，Ni-25at.-%Al混合粉末成为无序的亚稳定Ni固溶体，而Ni3Al预合金粉末由L12型长程有序金属间化合物转变为fcc无序固溶体；球磨更长时间，则形成纳米晶。