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主讲人：林栋（普渡大学西拉法叶校区）

题目1：Improving fatigue performance of additive manufactured metal structures by ultra-stable microstructures.

题目2:：3D printing of graphene aerogel

时间：2015-12-22（星期二）8：30~11:00

地点：武汉大学新普京澳门娱乐场app网站学术报告厅

举办单位：武汉大学新普京澳门娱乐场app网站

摘要1：Currently, additive manufacturing is a popular topic, while laser based additive manufacturing is the most applied technique for metal based additive manufacturing. Laser based additive manufacturing can be used to print complex, hard machining materials and large components. However, the major issue for laser based additive manufacturing is that it introduces thermal tensile stress, which decreases fatigue life of metal components. Fatigue is responsible for 90% of metal failure. In order to improve fatigue life of metal component, a two step manufacturing technology, including laser sintering plus laser shock peening (LSP), was proposed. First, 0D (Nanoparticles), 1D (carbon nanotube) and 2D (graphene or graphene oxide) nanomaterials were integrated into metal matrix by laser sintering. Then laser shock peening was performed to introduce high density of dislocations and novel microstructures. Compressive residual stress and surface work hardening were also introduced by LSP. The interaction between dislocations with nanomaterials helped block dislocation movement, thus stabilizing residual stress and work hardening. The stabilized work hardening and residual stress increased the resistance for crack initiation and crack propagation, so that we can greatly improve fatigue life.

摘要2：Graphene aerogel transfers inherent properties of graphene into macroscopic applications for composite materials, energy storage, stress sensor, thermal insulator and shock damping. However, fabrication of graphene aerogel with tailored macrostructures utilizing scalable and controllable methods remains a significant challenge. Here we report rapid three-dimensional printing of graphene aerogel architectures by coupling multi-nozzle drop-on-demand inkjet printing of pure graphene oxide suspension with freeze casting. Moreover, this 3D printing technique also enables aligning microstructure of printed graphene aerogel along printing direction. Based on our knowledge, we firstly demonstrate 3D printed graphene aerogel truss architecture with overhang features.The 3D printed graphene aerogels are ultra-light densities (from 0.5 to 10 mg cm^-3), significant electrical conductivity (~ 15.4 S m^-1), and high compressibility, and they are much stiffer than their counterparts, such as bulk GA with comparable density. Adapting this novel methodology realizes the design and fabrication of complex 3D graphene aerogels architectures on myriad applications.

个人简历见附件：/pmcnew/admin/editor/attached/file/20151220/20151220214838953895.pdf