Role of Si in the Surface Damage Mechanism of RB-SiC/Si Under Mechanical Loading

Quanli Zhang (Corresponding Author), Zhen Zhang, Honghua Su, Qingliang Zhao, Suet To

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)

Abstract

Indentation test (Nanoindentation and Vickers indentation), diamond scratching and high spindle speed grinding are conducted to investigate the role of silicon (Si) in the surface damage behavior of reaction-bonded SiC/Si composites (RB-SiC/Si). Even though the addition of Si contributes to densifying the bulk materials and improving the toughness, the indentation and diamond scratching results firstly indicate that the cracks initiate at the SiC/Si interfaces due to the non-uniform deformation caused by the existence of Si, and the phase transformation of Si also leads to the pop-out effect during the nanoindentation and the diamond scratching test. The ground surface of RB-SiC/Si is characterized by scratching grooves and brittle fracture, indicating the ductile material removal mode and brittle material removal mode for RB-SiC/Si, respectively, and the surface reliefs form on the ground surface due to the different hardness between Si and SiC phases. Moreover, the phase transformation of Si contributes to the easy fracture of phase boundaries under the mechanical loading, and the accompanied volume change also results in the dislodgement of hard particles and the generation of surface burs on the ground surface.

Original languageEnglish
Pages (from-to)254-262
Number of pages9
JournalJournal of Materials Engineering and Performance
Volume28
Issue number1
DOIs
Publication statusPublished - 1 Jan 2019

Keywords

  • fracture
  • grain boundaries
  • grinding
  • phase transformation
  • RB-SiC/Si

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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