Fracture toughness and sliding properties of magnetron sputtered CrBC and CrBCN coatings

Qianzhi Wang, Fei Zhou, Qiang Ma, Mauro Callisti, Tomas Polcar, Jiwang Yan

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

CrBC and CrBCN coatings with low and high B contents were deposited on 316L steel and Si wafers using an unbalanced magnetron sputtering system. Mechanical properties including hardness (H), elastic modulus (E) and fracture toughness (KIc) as well as residual stresses (σ) were quantified. A clear correlation between structural, mechanical and tribological properties of coatings was found. In particular, structural analyses indicated that N incorporation in CrBC coatings with high B content caused a significant structural evolution of the nanocomposite structure (crystalline grains embedded into an amorphous matrix) from nc-CrB2/(a-CrBx, a-BCx) to nc-CrN/(a-BCx, a-BN). As a result, the hardness of CrBC coating with high B content decreased from 23.4 to 16.3 GPa but the fracture toughness was enhanced. Consequently, less cracks initiated on CrBCN coatings during tribological tests, which combined with the shielding effect of a-BN on wear debris, led to a low friction coefficient and wear rate.

Original languageEnglish
Pages (from-to)635-643
Number of pages9
JournalApplied Surface Science
Volume443
DOIs
Publication statusPublished - 2018 Jun 15

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Keywords

  • Ceramic bearings
  • CrBCN
  • Fracture toughness
  • Sliding properties
  • Wear mechanism

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

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