纳米叠层Ni-Al基活性复合材料微观组织与力学性能及释能特性关系研究

“Reactive Materials” refer to those advanced energetic materials consisting oftwo or more solid-state reactants that either react with themselves (thermites, intermetallics) or combust violently with air (Al, Ti, Hf) upon impact, and thenreleasing higher predicted thermo-chemical energy per unit volume thanconventional energetics. Warhead shell and charge can combine perfectly if the Reactive Materials are used scientifically, and traditional munitions may get an outstanding upgrade. Today, large amount of active materials are difficult to achieve density, strength and energy release properties of a good match, while the Ni/Al Multilayer Nanofoils Matrix Reactive Composites (MNMRC) can be relatively easy to achieve excellent comprehensive performance. But, a series of important scientific questions directly related to the application have not been studieddeeply because the researchers on MNMRC cannot understand the subject application environment clearly. For examble, (1) The relationship between the Ni/Al MNMRCs’microstructure and dynamic mechanical properties and deformation, fracturelaw at high strain rate loading. (2) The Ni/Al MNMRCs’ energy release characteristics for example energy release rate, reaction enthalpy and ignition temperature et al and mechanisms, and so on..The solving of these basic problems related to the application will drive largely the Ni/Al Multilayer Nanofoils Matrix Reactive Composites’ use in theweapons.

活性材料是指由两种或两种以上固态反应物混合而形成的在高速碰撞过程中可自身发生或可在空气中发生剧烈反应而释放热化学能的一类新型含能材料。其应用可以实现战斗部壳体与装药的有机结合，很大程度上推动传统弹药的升级换代。当前，大量活性材料体系均难以实现密度、强度和释能等性能的良好匹配，以纳米叠层Ni-Al为基制备的全金属活性材料则可以较容易的获得优异的综合性能，是很有希望在武器型号上得到实际应用的结构功能一体化材料。但，一系列与活性复合材料制备和应用直接相关的重要科学问题尚未进行深入研究，包括：纳米叠层Ni-Al基活性复合材料微观组织特别是界面、互混层深度等与动态力学性能和释能特性的关系；与目标高速碰撞过程中的动态反应阈值、能量释放率等释能特性及机理等。相关基础问题的深入认识必将推动纳米叠层Ni-Al基活性复合材料在武器型号上的应用。

本项目针对微米级活性材料力学强度低、反应敏感性低、放热不足等问题，以Ni-Al金属基活性材料为研究对象，采用冷喷涂技术、EB-PVD等技术制备了高性能金属基活性材料。系统开展了多道次轧制、第三组元(第三组元分别为Al12Mg17/CuO/Ta) 添加等研究工作。实现了对Ni-Al活性材料的力学性能、反应敏感性和放热量的有效调控。获得如下研究成果：①通过多道次轧制的方法有效提高了材料内部的变形储存能与Ni、Al组元间的接触面积，进而降低了Ni-Al活性材料的反应起始温度，并提高其自蔓延燃烧速度，建立了组元间接触面积与燃烧速度之间的数学模型；②Al12Mg17依靠自身的氧化燃烧特性实现了对冷喷涂Ni-Al活性材料静态点火条件下反应性能的改善，包括降提高燃烧速率及提高反应剧烈程度；③CuO添加后则通过一种多阶段反应机制，即由起始的Ni、Al反应引发后续的铝热反应与氧化燃烧反应，实现了在不降低材料反应敏感性的前提下有效提高材料放热的目标；④Ta组元的加入主要提高材料的密度与力学强度，进而提高Ni-Al活性材料在高速冲击条件下的侵彻效果。