再生碳纤维增强点阵金属泡沫铝复合材料的静动态力学性能及其强韧化机制研究

Based on the most typical sandwich panel with aluminum foam-filled lattice core regarded as one of the proposed new generation of lightweight composite porous materials, according to the needs of engineering and science, the microstructure-controllable sandwich panels with aluminum foam-filled lattice cores reinforced by recycled carbon fibers and their derived materials are designed and fabricated, with particular emphasis on studying the effect of lattice truss core configuration and structure parameters, length diameter ratio of recycled carbon fibers and their surface treatments on the rheologic behavior of the aluminum melt foam, and their growth and evolution. The characterization of the static and dynamic mechanical properties of such composite porous metal materials is studied, and their toughening mechanisms are analyzed. The influence of long-diameter ratio and volume ratio of recycled carbon fibers, and other parameters on the deformation modes of such quasi-static mechanical tests as compressive, shear, and three-point bending of composite structure is studied. Combined with theoretical analysis, experimental research and numerical simulation, their quantitative relationship between macroscopically mechanical performance and microstructure is revealed, and the accurate description on quasi-static mechanical behavior of these materials and failure modes is achieved. Theoretical models on dynamic elastic-plastic constitutive relationship of these material and their dynamic damage energy are set up, practical analysis of stress wave propagation and absorption in such composite porous metal materials under the impact loads of drop hammer, Hopkinson pressure bar, etc. is proposed, and the evaluation of the technical parameters on energy absorbing properties of these materials is given.

在所提出最为典型的新一代轻质复合多孔材料-波纹泡沫铝复合结构基础上，根据工程和科学的需求，本申请主要侧重研究泡沫铝发泡填充过程中点阵金属构型和结构参数、再生碳纤维表面处理状态及长径比、体积比等参数对熔体泡沫流变特性及生长演变的影响，从而设计和制备微观结构可控的再生碳纤维强韧化点阵金属泡沫铝复合结构及其衍生材料。在此基础上,建立该类复合多孔金属材料静动态力学性能的表征方法和技术，分析其强韧化机制。研究碳纤维长径比、体积比等参数对复合结构压缩、三点弯曲等变形模式的影响，结合理论分析、实验研究和数值模拟，揭示其宏观性能与微细观组织结构间定量关系，实现对该类材料的准静态力学行为和破坏模式准确描述；建立材料的动态弹塑性本构关系和动态损伤能等理论,提出一套切实可行的分析由落锤、Hopkinson压杆等冲击载荷产生的应力波在复合多孔金属材料中传播和吸收机理的方法，给出评价该类材料能量吸收性能的技术参数。

项目研究立足于车辆防雷板、航天发动机燃烧室等国家目标需求，提出和制备了系列的点阵金属复合材料，典型的有碳纤维增强泡沫铝-点阵金属夹层板、碳纤维增强PMI泡沫-点阵金属夹层板、石墨烯增强PMI泡沫-点阵金属夹层板、波纹-四方蜂窝复合夹层钎焊结构、X型点阵与平板翅复合芯体三明治板、波纹通道芯体夹层结构等。提出一种可规模化在波纹板骨架中形成泡沫铝的复合结构的粉末冶金原位发泡制备方法，形成冶金界面可有效地增强泡沫铝与波纹芯体、面板的连接强度。为了研究该复合结构制备过程中技术关键-闭孔泡沫铝的凝固行为，给出凝固界面随时间推移的解析解，并以水为介质采用实验和数值模拟加以验证，结果吻合很好。建立该类多孔金属材料静态力学性能的表征方法和技术，分析其强韧化机制。理论分析了泡沫填充夹芯梁在横向弯曲载荷下可能发生的六种破坏模式：面板屈曲和屈服破坏，芯体剪切屈曲和屈服破坏，芯体压痕屈曲和屈服破坏。构建了破坏模式图，并在此基础上进行最小质量结构优化。建立该类多孔金属材料动态力学性能的表征方法和技术，其中如何提高装甲车对地雷等爆炸物的爆炸波和碎片的耦合作用防护能力，是一个在强动载防护领域受到日益关注的研究课题，为此设计和搭建实验室内模拟爆炸冲击的泡沫子弹和内置碎片冲击专用实验平台，对相关结构进行了细致的实验测试分析，为上述点阵金属复合材料的实际工程应用提供了详实数据和设计参考。系统阐述了蜂窝这种古老的结构形式在传统的工程以及新兴的微纳制造等领域基础与应用的最新进展，该工作形成的长篇论文 “Bioinspired Engineering of Honeycomb Structure - Using Nature to Inspire Human Innovation” 在线发表在国际材料领域旗舰类期刊Progress in Materials Science（2017年公布的影响因子为31）上。项目研究周期内共在国内外学术期刊上发表学术论文31篇，其中SCI收录论文25篇，申请发明专利16项，授权申请发明专利5项。所研制的防雷板材已获得部分应用推广，航天发动机燃烧室已通过相关研究所考核实验，圆满完成了预定研究任务，达到了预期研究目标。