Tailoring the properties of spark plasma sintered SiAlON containing graphene nanoplatelets by using different exfoliation and size reduction techniques: Anisotropic mechanical and thermal properties

Cinar A., BAŞKUT S., SEYHAN A. T., TURAN S.

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, vol.38, no.4, pp.1299-1310, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 38 Issue: 4
  • Publication Date: 2018
  • Doi Number: 10.1016/j.jeurceramsoc.2017.10.004
  • Journal Name: JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1299-1310
  • Keywords: SiAlON, Graphene nanoplatelets (GNPs), Microfluidization, Mechanical properties, Thermal properties, SILICON-NITRIDE, FUNCTIONALIZED GRAPHENE, ALUMINUM NITRIDE, CONDUCTIVITY, STABILITY
  • Anadolu University Affiliated: Yes

Abstract

SiAlON ceramics are intensively used in different areas but still there is a need to improve the mechanical and thermal properties as well as ease of machinability and reduce the weight. In this study, the effect of graphene nanoplatelets (GNPs) exfoliation and dispersion techniques on the microstructure and properties of SiAlON ceramics were investigated. For this purpose, 2, 4 and 8 wt% GNPs were dispersed by using traditional sonication and newly proposed microfluidization techniques. Then, composites were densified in spark plasma sintering (SPS) furnace. Scanning electron microscope (SEM), x-ray diffraction analyses (XRD) and property measurements were performed in through-plane and in-plane directions. The microfluidization technique found to be more effective than sonication for the exfoliation, size reduction and homogenization of GNPs. Addition of GNPs prepared by both techniques increased the fracture toughness and in-plane direction thermal conductivity whereas decreased the hardness and through-plane direction thermal conductivity of the SiAlON.