Microstructure and Thermal Conductivity of Al–Graphene Composites Fabricated by Powder Metallurgy and Hot Rolling Techniques

• Published in: Acta metallurgica sinica : English letters 2017-07, Vol.30 (7), p.675-687
• Main Authors: Saboori, Abdollah, Pavese, Matteo, Badini, Claudio, Fino, Paolo
• Format: Article
• Language: English
• Subjects: Alloys; Aluminum; Aluminum carbide; Carbon; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composite materials; Corrosion and Coatings; Diamond pyramid hardness; Diffraction patterns; Dispersion; Ductility; Ethanol; Grain refinement; Graphene; Heat conductivity; Heat transfer; Hot rolling; Investigations; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Morphology; Nanocomposites; Nanotechnology; Organometallic Chemistry; Powder metallurgy; Scanning electron microscopy; Sintering (powder metallurgy); Spectroscopy/Spectrometry; Thermal conductivity; Tribology; 制造技术; 国民生产总值; 热连轧; 石墨; 粉末冶金; 纳米复合材料; 组织观察; 高铝
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-017-0579-2

The objective of this research is to improve the thermal conductivity and mechanical properties of Al/GNPs（graphene nanoplatelets） nanocomposites produced by classical powder metallurgy and hot rolling techniques. The microstructural evaluation confirmed the uniform dispersion of GNPs at low content and agglomeration at higher contents of GNPs. The structure of graphene was studied before and after the mixing and the Raman spectrum proofs that the wet mixing has a great potential to be used as a dispersion method. There was no significant peak corresponding to the Al_4C_3 formation in both the differential scanning calorimetry curves and X-ray diffraction patterns. The microstructural observation in both fabrication techniques showed grain refinement as a function of the GNPs content. Moreover, the introduction of the GNPs not only improved the Vickers hardness of the composites but also decreased their density. The thermal conductivity investigations showed that in both the press-sintered and hot-rolled samples, although the thermal conductivity of composites was improved at low GNPs contents, it was negatively affected at high GNPs contents.