Microstructure evolution and superior tensile properties of low content graphene nanoplatelets reinforced pure Ti matrix composites

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 687; pp. 164 - 174
• Main Authors: Mu, X.N., Zhang, H.M., Cai, H.N., Fan, Q.B., Zhang, Z.H., Wu, Y., Fu, Z.J., Yu, D.H.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 27-02-2017; Elsevier BV
• Subjects: Deformation mechanisms; Grain refinement; Graphene; Graphene nanoplatelets; Hot rolling; Load transfer; Mechanical properties; Metal matrix composites; Microstructure; Microstructure evolution; Plasma sintering; Powder metallurgy; Rolling direction; Spark plasma sintering; Tensile properties; Titanium; Titanium matrix composites; Ultimate tensile strength; Mechanical properties; Graphene nanoplatelets; Microstructure evolution; Titanium matrix composites
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2017.01.072

Titanium matrix composites with the discontinuous reinforcement of graphene nanoplatelets (GNPs) were produced by powder metallurgy and subsequent hot-rolling. In the process of spark plasma sintering (SPS), the GNPs were well preserved at low temperature and high compressive pressure. Hot-rolling process was applied to improve the microstructure and properties of the GNPs-Ti matrix composites. The GNPs were uniformly distributed and arranged along with the rolling direction (RD). Also, the GNPs blocked slipping so that the matrix generated {101̅1} <101̅2̅> compressive twining to be compatible with deformation in the rolling process with the increase of GNPs content. Tensile strength test demonstrated an excellent ultimate tensile strength that was 54.2% higher than pure titanium with merely 0.1wt% GNPs addition. The strengthening mechanism of composites was discussed by three main strengthening factors combined with a modified load transfer model and it was thought that the composites were strengthen by grain refinement, load transfer from Ti matrix to GNPs and texture strengthening.