Production, Structure and Properties of Nanocarbon Reinforced Metal Matrix Composites

  • Fei Lin

Student thesis: Phd


Aluminium (Al) matrix composites, reinforced with 0.3, 0.5 or 1.0 wt. % graphene oxide (GO) or 0.5 wt. % carbon nanotubes (CNTs) were fabricated by the powder metallurgy (PM) method comprised a ball milling step followed by hot extrusion. The microstructure, texture, interfacial reactions and mechanical behaviours of the composites were analysed and discussed and compared with the control aluminium samples. In particular, in-situ Raman spectroscopy was conducted during four-point bending tests to investigate the interfacial stress transfer between the GO/CNTs and the Al. The Al/GO composite exhibited a more refined microstructure than pure Al due to the pinning effects of GO, which led to improved mechanical properties. Whereas, the Al/CNT composite, possessed the same mean grain size as the unreinforced material and exhibited a decreased compressive yield stress, which was attributed the low load transfer to the nanotubes due to their large degree of agglomeration. Copper-tungsten composites were produced by decorating graphene oxide (GO) flakes with 8 nm diameter CuWO4.2H2O nanoparticles and then sintering them to form the final component. The oxide nanoparticles were found to self-assemble into platelets from the surfaces of the graphene flakes. Upon sintering, the presence of graphene changed the final grain morphology from an elongated needle to a polyhedral shape. The oxide nanoparticles were not fully reduced to a pure metal, whereas the GO was hydrogenated after the sintering, verified by Raman spectroscopy. Cu-W matrix composites with different loadings of GO were also successfully produced by flake powder metallurgy which comprised of ball milling followed by spark plasma sintering. Composites at all the loadings GO used (0.1 - 0.5 wt. %) showed improved modulus relative to the base Cu20W80 system. The optimal loading was found to be 0.1 wt. % GO for composites sintered at temperatures of both 1000 and 1100 degree Celsius. These composites had a higher Youngs modulus, yield strength, ultimate compressive strength, strain to failure and electrical conductivity than the control samples. The mechanical performance was further improved at the higher temperature of 1100 degree Celsius. The wear resistance the Cu20W80 was not affected by the addition of graphene. Higher loadings of graphene were found to embrittle the composites and reduce their electrical conductivity of the composites.
Date of Award3 Jan 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorRobert Young (Supervisor) & Ian Kinloch (Supervisor)


  • Metal matrix composite
  • Graphene oxide
  • Carbon nanotube

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