Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation disp...Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density （2.94 g/cm^3）, high elastic modulus （220 GPa）, prominent thermal management function as a result of low coefficient of thermal expansion （8 × 10^4 K^-1） and high thermal conductivity （235 W/（m.K）） as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.展开更多
The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environmen...The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environment.Carbon nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above goal.In this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking structures.The fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 420%compared to neat SA-CNTF.More importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based materials.The hierarchical energy dissipation mechanism was further revealed through experiment and simulation.Additional functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.展开更多
基金Foundation items： High-technology Research and Development Programme of China （2007AA03Z544） Aeronautical Science Foundation of China （20075221001）
文摘Multi-functional Al-matrix composites with high volume fraction （55%-57%） of SiC particles are produced with the new pressureless infiltration fabrication technology. X-ray detection and microscopic observation display the composites which are macroscopically homogeneous without porosity. The investigation further reveals that the SiC/Al composites possess low density （2.94 g/cm^3）, high elastic modulus （220 GPa）, prominent thermal management function as a result of low coefficient of thermal expansion （8 × 10^4 K^-1） and high thermal conductivity （235 W/（m.K）） as well as unique preventability of resonance vibration. By adopting a series of developed techniques, the multi-functional SiC/Al composites have managed to be made into near-net-shape parts. Many kinds of precision components of space-based optomechanical structures and airborne optoelectronic platform have been turned out. Of them, several typical products are being under test in practices.
基金supported by the National Key Basic Research Program of China(No.2022YFA1205400)the Chinese Postdoctoral Science Foundation(Nos.E1I41IR1 and E2911IR1).
文摘The fabrication of light-weight,highly impact-resistant,and energy-absorbent materials is urgently demanded in many facets of the society from body armor to aerospace engineering,especially under an extreme environment.Carbon nanotubes(CNTs),one of the strongest and toughest materials ever found,also have good conductivity,chemical stability,and thermal stability,etc,making them a competitive candidate as building blocks to help achieve the above goal.In this work,a kind of CNT network was prepared by using chlorosulfonic acid(CSA)to release the internal stress of super-aligned carbon nanotube films(SA-CNTF)and dendritic polyamide amine(PAMAM)to further introduce multiple hydrogen bonds and interlocking structures.The fabricated bioinspired carbon nanotube network films(PAMAM@C-CNTF)have a high toughness of 45.97 MJ/m3,showing an increase of 420%compared to neat SA-CNTF.More importantly,the anti-impact performance of the films(e.g.,with a maximum specific energy absorption of 1.40 MJ/kg under 80-100 m/s projectile impact)is superior to that of conventional protective materials from steel and Kevlar fiber,and also exceeds that of any other reported carbon-based materials.The hierarchical energy dissipation mechanism was further revealed through experiment and simulation.Additional functions including intelligent heating/anti-icing,ultraviolet protection,as well as electromagnetic interference shielding properties make these network films have great potential in practical multi-protection applications,especially under an extreme environment.
