Materials (May 2024)

Effect of Si<sub>3</sub>N<sub>4</sub> Additive on Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Cutting Tools

  • Ali Elgazzar,
  • Sheng-Jian Zhou,
  • Jia-Hu Ouyang,
  • Zi-Jian Peng,
  • Jun-Teng Yao,
  • Zhan-Guo Liu,
  • Yu-Jin Wang,
  • Ya-Ming Wang

DOI
https://doi.org/10.3390/ma17112586
Journal volume & issue
Vol. 17, no. 11
p. 2586

Abstract

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Development of high-performance cutting tool materials is one of the critical parameters enhancing the surface finishing of high-speed machined products. Ti(C,N)-based cermets reinforced with and without different contents of silicon nitride were designed and evaluated to satisfy the requirements. In fact, the effect of silicon nitride addition to Ti(C,N)-based cermet remains unclear. The purpose of this study is to investigate the influence of Si3N4 additive on microstructure, mechanical properties, and thermal stability of Ti(C,N)-based cermet cutting tools. In the present work, α-Si3N4 “grade SN-E10” was utilized with various fractions up to 6 wt.% in the designed cermets. A two-step reactive sintering process under vacuum was carried out for the green compact of Ti(C,N)-based cermet samples. The samples with 4 wt.% Si3N4 have an apparent solid density of about 6.75 g/cm3 (relative density of about 98 %); however, the cermet samples with 2 wt.% Si3N4 exhibit a superior fracture toughness of 10.82 MPa.m1/2 and a traverse rupture strength of 1425.8 MPa. With an increase in the contents of Si3N4, the Vickers hardness and fracture toughness of Ti(C,N)-based cermets have an inverse behavior trend. The influence of Si3N4 addition on thermal stability is clarified to better understand the relationship between thermal stability and mechanical properties of Ti(C,N)-based cermets.

Keywords