TY - JOUR
T1 - Sp2 carbon embedded in Al-6061 and Al-7075 alloys in the form of crystalline graphene nanoribbons
AU - Jaim, H. M.Iftekhar
AU - Isaacs, Romaine A.
AU - Rashkeev, Sergey N.
AU - Kuklja, Maija
AU - Cole, Daniel P.
AU - LeMieux, Melburne C.
AU - Jasiuk, Iwona
AU - Nilufar, Sabrina
AU - Salamanca-Riba, Lourdes G.
N1 - Funding Information:
The Al-covetic samples were provided by Third Millennium Materials, LLC. This work was supported in part by ONR under contract N000141410042 and DARPA/ARL under contract W911NF13100 . DPC is a contractor to the U.S. Army Research Laboratory under contract W911QX-13-D-0003 . IJ gratefully acknowledges support from the National Science Foundation , the CMMI Program Grant 12-34130 . The authors are thankful to Dr. Karen Gaskell at the Surface Analysis Center, UMD for her thoughtful discussions regarding XPS data. We acknowledge the use of the TEM at the University of Maryland Nanocenter and its AIM Laboratory.
Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2016/10/1
Y1 - 2016/10/1
N2 - Electrocharging assisted process has been used to incorporate carbon in Aluminum 6061 and 7075 alloys ensuing significant improvements of the ultimate tensile strength, hardness, and electrical conductivity. This work investigates the presence of carbon, its structure, carbon-metal bonding, surface characterization and dispersion of carbon incorporated in Al alloys by electrocharging assisted process. Networks of Graphene nanoribbons with 3D epitaxy and preferred orientation along the 〈110〉 and 〈112〉 directions of Al are evident by transmission electron microscopy and spectrum imaging of the C[Formula presented]K edge electron energy loss spectra. X-ray photoelectron spectroscopy and Raman scattering corroborate sp2 carbon in Al-6061, and hybrid sp2-sp3 in Al-7075 with added carbon. Kelvin probe force microscopy substantiates the presence of carbon in the Al matrix. Phonon density of states derived from first-principles calculations predicts C[Formula presented]Al Raman active modes whilst density functional theory indicates covalent bonding between carbon and Al. This method of incorporation of graphene nanostructures in metals with strong carbon-metal bonding can open up new avenues for incorporation of sp2 carbon structures in other materials.
AB - Electrocharging assisted process has been used to incorporate carbon in Aluminum 6061 and 7075 alloys ensuing significant improvements of the ultimate tensile strength, hardness, and electrical conductivity. This work investigates the presence of carbon, its structure, carbon-metal bonding, surface characterization and dispersion of carbon incorporated in Al alloys by electrocharging assisted process. Networks of Graphene nanoribbons with 3D epitaxy and preferred orientation along the 〈110〉 and 〈112〉 directions of Al are evident by transmission electron microscopy and spectrum imaging of the C[Formula presented]K edge electron energy loss spectra. X-ray photoelectron spectroscopy and Raman scattering corroborate sp2 carbon in Al-6061, and hybrid sp2-sp3 in Al-7075 with added carbon. Kelvin probe force microscopy substantiates the presence of carbon in the Al matrix. Phonon density of states derived from first-principles calculations predicts C[Formula presented]Al Raman active modes whilst density functional theory indicates covalent bonding between carbon and Al. This method of incorporation of graphene nanostructures in metals with strong carbon-metal bonding can open up new avenues for incorporation of sp2 carbon structures in other materials.
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U2 - 10.1016/j.carbon.2016.05.053
DO - 10.1016/j.carbon.2016.05.053
M3 - Article
AN - SCOPUS:84977136792
SN - 0008-6223
VL - 107
SP - 56
EP - 66
JO - Carbon
JF - Carbon
ER -