增材制造多孔Cu-Ni合金用于CVD法制备三维石墨烯基础研究

Three-dimensional (3D) graphene architectures refer to the assemblies of two-dimensional (2D) graphene with 3D porous structures. 3D graphene possesses more excellent properties such as higher specific surface area and structural stability without re-stacking compared to traditional 2D graphene, thus exhibiting a wider application area and more promising prospect. Porous metals acting as templates play a significant role in determining the structures and performance of 3D graphene prepared by chemical vapor deposition (CVD). However, prous metal templates prepared by traditional processes such as common used stochastic Ni foams have a random distribution of open or closed voids, leading to uncontrollable structures and unstable properties of 3D graphene. Therefore, this project creatively proposes that: (1) porous Cu-Ni alloy with customized and complex structures is prepared by selective laser melting (SLM) additive manufacturing technology and then employed as templates for preparing 3D graphene by CVD. Through computer-aided design modeling and SLM manufacturing of macroscopic pore characteristics (unit cell type, porosity and pore size) of porous Cu-Ni alloy, the macrostructure of 3D graphene can be precisely controlled ; (2) the microstructure of 3D graphene can be tailored by varying the microscopic features of SLM-made porous Cu-Ni alloy including element ratio, microstructure, crystallographic texture, and surface finish. To realize the innovative thoughts mentioned above, this project will address some fundamental problems such as the evolution and regulation mechanism of the microstructure, crystallographic texture and surface finish of porous Ni-Cu alloy in SLM and post processing, and influence law of macro/microscopic features of SLM-made porous Cu-Ni alloy on the structure and properties of 3D graphene. This project is supposed to achieve the original research findings in metallurgical mechanism of Cu-Ni alloy in SLM and prost processing, and micro/macro-structural and property regulation of 3D graphene. It is envisaged that the success of the present research project can break through the bottle-neck of structural control of 3D graphene, and thus considerably extend its application scope.

三维（3D）石墨烯具有较单层石墨烯更优越的性能和广阔的应用前景。在使用化学气相沉积（CVD）法制备3D石墨烯时，多孔金属作为模板对其结构与性能起决定性作用，然而传统方法制备的多孔金属模板具有无规孔结构，造成3D石墨烯结构不可控、性能重复性差。为此，本项目提出：激光选区熔化（SLM）增材制造多孔Cu-Ni合金，并将其用于CVD法制备3D石墨烯，通过设计与精确制造多孔合金宏观孔特性（单元类型、孔隙率及孔径）实现对石墨烯宏观结构的精确控制；通过对多孔合金微观特性（元素配比、微观组织、织构及表面质量）的调节，实现对石墨烯微观结构的有效调控。课题主要解决实现该思路的若干基础问题，如SLM及后处理中多孔合金微观组织、织构及表面质量的演变与调控、多孔合金的宏微观特性对石墨烯结构与性能的影响规律等。本项目的研究对突破3D石墨烯结构控制难题，促进其工程应用具有重要的科学和工程意义

三维（3D）石墨烯材料兼具比表面积大、结构稳定不团聚、电子传导能力优越及传质快速等优良特性，在储氢、催化、传感器、超级电容器及柔性/可伸缩导电材料等领域具有较单层石墨烯更优越的性能和更广阔的应用前景。其结构可控性、性能稳定性对于三维石墨烯材料的应用起到至关重要的作用。本项目提出利用激光选区熔化（SLM）增材制造多孔合金，将其用于CVD法制备3D石墨烯；并探索增材制造多孔结构的静态力学与动态疲劳性能。.本项目主要研究内容及重要结果如下：①揭示了Cu-Ni合金的冶金机理并优化得到其SLM工艺成形窗口。通过正交实验优化成形工艺参数，进而得到致密的Cu-Ni合金块体材料。②揭示了在不同微观特性的多孔结构模板上石墨烯的生长机制。利用不同元素比例的Cu-Ni合金粉末制备多孔结构模板以达到对多孔结构模板微观特性的调控。研究表明在CuNi原子比分别为1:3的多孔模板上进行CVD石墨烯生长可以得到覆盖率高、缺陷少的石墨烯片层。③探索了CVD法生长石墨烯不同工艺参数对于生长石墨烯结构的影响规律，并制备了Cu-Ni-石墨烯复合材料。研究表明温度增高使裂解C溶解度急剧增加，抑制了石墨烯的生成。与未生长石墨烯样品相比，复合材料的热扩散系数提高了12.5%。④提出了基于SLM制备多孔结构的改进Johnson-Cook本构模型，用于多孔结构的力学性能预测，并建立了多孔结构的内部应力分布与疲劳失效的定性分析数学模型。.本项目的执行过程，参加国际会议5人次，在Acta Mater.等国际重要学术期刊发表SCI论文26篇（其中第一标注论文11篇），授权发明专利4项，培养研究生6名，部分成果获2018年国家科技进步二等奖（项目负责人排第三），超额完成预期研究目标。本课题的研究对于突破增材制造多孔合金材料形性控制和有序3D石墨烯制备，并促进其工程应用，具有重要的科学和工程意义。

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