Production and characterization of spark plasma sintered (Ti,Nb)B2 solid solutions with graphene nanoplatelets and hexagonal boron nitride

Kaplan Akarsu M., Akın Karadayı İ.

Ceramics International, vol.49, no.4, pp.5582-5594, 2023 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 49 Issue: 4
  • Publication Date: 2023
  • Doi Number: 10.1016/j.ceramint.2022.10.155
  • Journal Name: Ceramics International
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.5582-5594
  • Keywords: Borides, Solid solution, GNP, h-BN
  • Istanbul Technical University Affiliated: Yes

Abstract

For this study, (Ti,Nb)B2 solid solutions were consolidated by spark plasma sintering. In addition, (Ti,Nb)B2 with graphene nanoplatelets (GNPs) and hexagonal boron nitride (h-BN) were produced to evaluate the potential of the new structural materials. The phase formation, microstructure, mechanical properties, oxidation resistance and room temperature reflectance, and absorbance features of (Ti,Nb)B2 were investigated. X-ray diffraction and Transmission electron microscopy observations showed that a complete solid solution phase was formed when the samples were sintered at 1850 °C for 5 min under 50 MPa. Ti0.75Nb0.25B2 exhibited a relative density of ∼98.6%, a hardness of ∼20.5 GPa, and an indentation fracture toughness of ∼3.4 MPa·m1/2. It was found that the presence of 1 vol% h-BN as an additive enhanced the hardness (∼10%) and fracture toughness (∼30%) of Ti0.75Nb0.25B2 by activating toughening mechanisms. The GNP added Ti0.75Nb0.25B2 proved to have better oxidation resistance and optical absorbance than the other materials used in the study.