Manufacturing of near net shape bulk nanostructured materials

纳米材料（即粒径分布在1到100纳米之间的材料）的主要兴趣在于与微米尺度的材料相比，可以实现新的机械和化学性能：优越的静态和动态机械强度、超塑性、高应变速率流动性、增强的耐腐蚀性和耐磨性。纳米材料可能获得的性能增益在所有技术领域都产生了热情。阻碍它们大规模使用的实际挑战是，能否以具有竞争力的价格制造出完美无瑕的大规模批量部件。近净形状加工路线可以显著降低材料和加工成本，并减少在后期固结操作中引入关键缺陷的可能性，这将有助于其商业化和实施。然而，纳米材料的近净形状加工工程尚处于起步阶段，对材料行为的进一步了解和加工条件的优化仍有待完成。因此，本研究计划旨在研究三种制备近净形状块状纳米结构材料的工艺：火花等离子烧结轧制、电火花焊接自由成形和控制短路金属惰性气焊。前两种加工路线将开发针对交通运输行业的大块纳米结构人工智能系统，而后一种加工路线将专注于用于磨损应用的纳米复合材料。该项目将产生商业上可行的工艺，能够生产几何形状的大规模块状纳米结构材料，并且成本对工业来说是负担得起的。

The major interest in nanomaterials, i.e. materials with a grain size distribution ranging from 1 to 100 nm, resides in the novel mechanical and chemical properties achievable compared to their micron-scale counterparts: superior static and dynamic mechanical strength, superplasticity, high strain rate flowability, enhanced corrosion and wear resistance. The possible gain in properties obtainable with nanomaterials creates an enthousiams in all technological sectors. The actual challenge preventing their utilization at large is the availability of processes to fabricate flawless large-scale bulk components at a competitive price. The near-net shape processing route enables significant material and processing cost reduction and reduces the possibility of introducing critical flaws during post-consolidation operations, which would help contributing to their commercialization and implementation. However, the engineering of near-net shape processing of nanomaterials is at its infancy and further understanding of the material's behavior and optimization of the processing conditions remains to be done. The present research proposal is therefore aimed at studying three processes to fabricate near net-shape bulk nanostructured materials: spark plasma sinter rolling, freeforming using electrospark welding and controlled short circuit metal inert gas welding. The two former processing routes will developed bulk nanostructured Al systems targeting the transportation industry, while the later will focus on nanocomposites for wear applications. This project will yield commercially viable processes capable of producing large-scale bulk nanostructured materials in geometries and at cost affordable to the industries.