【作者】 韩爱军；

【导师】 李凤生； 宋洪昌；

【作者基本信息】 南京理工大学 ， 材料学， 2002， 博士

【摘要】 超细粉体技术主要内容集中在超细粉体的制备、性能研究及应用研究三个方面。制备技术是指研究新的制备原理、制备方法及设备，目的在于能制备出更细、分布更窄更均匀的超细粉体；应用研究是将超细粉体应用到国民经济的各领域，并解决应用中所伴随的各种问题。而随着材料科学迅猛发展的需要，超细粉体性能研究将是超细粉体技术学科今后的主要任务，目的在于通过粒子设计对粒子进行改性或复合处理，力求研究出新的高性能复合超细粉体，使其具有多功能性，以提高超细粉体的使用性能与价值。 在超细粉体粒子的复合方法中，机械化学法由于具有良好的应用前景，越来越引起人们的高度重视。机械化学法的理论基础为机械化学，该学科是一门新兴的边缘和交叉性学科，主要研究各种凝聚状态下的物质因受机械力的影响而发生化学或物理化学变化的基本原理、规律及其应用，它的创建为新的化学物质和具有特定性能新材料的加工方法开辟了广阔的新领域。本论文在机械化学基本理论的基础上，根据相关领域的实际需要，利用不同超细粉碎机械力作用形式，研究制备了三种功能性超细复合粒子，并分析了HLGB双向旋转搅拌球磨、LS流能粉碎、LG立式高效研磨设备制备复合粒子时，超细粒子的受力状况及其吸收能，探索复合机理，为相应的工业化生产奠定基础。 1．超低碳钢连铸结晶器用保护渣中，外加中超碳黑作为骨架降低熔化速度，使保护渣具有良好的绝热保温性、均匀流动的润滑性，但同时却会引起钢铸坯的碳增量，最终影响超低碳钢的成功操作。本论文利用HLGB卧式双向旋转搅拌球磨设备，通过正反转搅拌齿及研磨珠工作时产生的强烈的剪切、研磨机械力持续作用于CaO／SiO₂熔融颗粒及中超碳黑颗粒表面，XPS检测表明，颗粒表面有Si-C及Ca-CO键生成，根据机械化学理论是由于机械力的作用，诱发利用热能难以进行的机械化学反应，在CaO／SiO₂熔融颗粒表面生成了SiC及CaCO₃新物质，构成包覆型复合粒子。由于碳化硅中的碳熔解到钢水中去的速度极小，而且有抑制游离碳熔解到钢水中去的作用，因此减少了钢铸坯碳增量。同时SiC的高熔点和CaCO₃分解反应的吸热效应将降低保护渣的熔化速度。 另一方面，在机械力作用下，碳黑及CaO／SiO₂的熔融颗粒被超细粉碎，比表面积增大，同时TEM照片显示，中超碳黑均匀地复合于超细熔融颗粒表面，并有逐步嵌入的趋势，提高了碳的有效利用率，降低了保护渣的熔化速度。应用单位实验表明：在不影响保护渣整体性能的前提下，使用超细复合粒子保护渣，降低熔速的外摘要博士学位论文加中超碳黑的量可大幅度减少，仅需0.3%，而使用传统方法制备的保护渣外加中超碳黑量不低于2%。因此避免了因保护渣中含碳量高而引起钢铸坯的碳增量。 2.当石墨用于隐身材料及“石墨炸弹”等军事领域时，需要石墨具有超细的粒径，同时在空气中能在一定时间内形成稳定悬浮的气溶胶。为此本文根据晶体石墨性质，采用对撞粉碎原理制备满足粒径要求的超微细石墨。依据机械化学原理利用LS一250型流能粉碎机高速旋转的动齿工作过程中产生的强烈冲击、碰撞机械力，使其作用于超细石墨及白碳黑颗粒表面，检测表明，石墨粒子表面晶格发生畸变及无定形化，且随着机械力作用时间的延长而加剧。在此过程中，超细粒子吸收大量能量处于亚稳定状态，物理化学性质相应发生变化，使得超细石墨被充分分散后作为子粒子均匀地吸附于白碳黑母粒子表面（特别是凹处），形成满足应用于军事领域特定功能需要的类球形结合紧密的石墨/白碳黑复合粒子。并且，通过建立的沉降重量百分数模型与理论沉降速度模型，以及红外吸收实验结果均表明，超细复合粒子形成的气溶胶具有较好的稳定性，且当白碳黑含量约为29%³0%时，悬浮稳定性最佳。 3，新一代环保型高效冷气溶胶灭火粉为化学抑制灭火机理，要求其灭火基料主成份（NaHC氏）粒径超细微，以便捕获自由基，中止燃烧链式反应，同时灭火粉被喷射后很快扩散到各个部位，实现全方位淹灭式灭火，而仅将灭火粉中主要成份的超细化将难以满足其喷射率、悬浮性及吸湿率要求。本文根据机械化学基本原理在针对NaHCO。在水和异丙醇不同介质中不同溶解度的特性制备超细NaHC03微粒后，利用LG一80型高效立式研磨通过搅拌盘带动研磨球在粉碎过程中产生的强烈的挤压、摩擦研磨机械力，作用于超细NaHC03和白碳黑粒子表面，由于颗粒粒径极小，机械能主要转化为粉体颗粒的位能，NaHC03表面单斜晶体畸变或无序化程度随机械力作用而加剧。颗粒储存大量能量后诱发了机械化学效应，超细NaHC03被分散后以原生粒子作为子粒子均匀地吸附于白碳黑颗粒表面，制备出满足冷气溶胶灭火粉功能需要的碳酸氢钠/白碳黑复合粒子。应用单位的实验表明，冷气溶胶复合粒子灭火粉除满足吸湿率（<2.2%）及喷射率（>94%）外，最低灭火量为609/mJ，灭火性能较普通干粉药剂高出3一4倍。 机械化学法在复合粒子制备中的应用研究，使得利用超细粉碎机械力制备各种功能性复合材料具有重要的理论意义和广泛的实用性，同时也促进了机械化学法的更多还原

【Abstract】 Superfine powder technology mainly includes the preparation, the properties researching and the study on the application of superfine powder. The superfine powder preparing technology is considered to research the new principle of the preparation, the method of preparation and concerning equipments. The aim is to prepare powders of much more fine, more narrow distribution and more uniform. What the research of application is to apply the superfine powder to national economy and solve all kinds of the problems following the application. But with the rapid development of the materials science, the research on the properties of superfine powder will become the main task of the superfine powder technology in the future. The aim of the research on the superfine powder properties is to prepare new, functional properties and complex superfine powder, by designing or compounding modification on superfine particles.In the composite methods of superfine powder, mechano-chemistry is more and more popular and received by majority, because this method has a splendid prospect application. It’s a new sort of cross subject. What’s the method of the mechano-chemistry is mainly find out the basic principle, rule and application of the physical-chemical reaction occurring to the superfine powder, in the effect of the mechanical force in all kinds of conditions. The appearing of mechano-chemistry method displays a new wide field for the processing of new materials. On the basis of the mechano-chemistry principles, three kinds of functional composite particles were prepared by different mechanical force, according to the actual requirement of commerce areas.1. The moderate supersonic carbon added to the mold flux for ultra-low carbon steel is used to stay the melting speed as skeleton. Then the mold flux coils have the good adiabatic, insulation and even flow property. At the same time it cause the carbon increase in the steel slabs and the operation of the ultra-low carbon is affected at last. The strong shear cut and grinding force of HLGB horizontal stirring grinding machine is used to the surface of the moderate supersonic carbon and the fusion particles of the CaO & SiO2 in this paper. The result of XPS indicated that the Si-C bond is detected on the surface of the particles. The high melting point superfine SiC and CaCO3 areproduced on the surface of CaO & SiO2, and composite particles are formed. As the melt speed of SiC in steel water is very slow and SiC has the function of restrain the melting of free carbon in steel water, so the contain of carbon in steel is decreased.On the other hand, under the force of mechanical, the carbon and CaO & SiO2 superfine powder are obtained; the specific surface area of these particles is increased. The TEM photos indicated that, the carbon particles are composites on the surface of the melting superfine particles uniformly. In doing so, the utilization rate of carbon is increased and the melting speed of protection slag is decreased. The application result indicated that: using superfine composite particles, only 0.3% of carbon is needed, while carbon in traditional particles would up to 2%. Hence, the adding of superfine composite powder can avoid the increasing of carbon in steel slag.2. When graphite is applied in the areas of war, such as the disappearing material, the Graphite Bomb and so on, superfine powder is needed and carbon in the form of steadily aerosol is required. According to the properties of the crystal carbon, the opposing pulverizer was employed to prepare the superfine carbon in this paper. Based on the principle of mechano-chemistry, the strong shock and crashing mechanical force produced by LS-250 pulverizer can act to the surface of superfine carbon and white carbon particles during the process. The result of the experiment indicated that distortion and amorphism change occur to the surface crystal lattice of carbon particles, and the phenomena are prick up as the action time of mechano-chemical force. In this processing, the superfine particles更多还原