Enhancement of tribological properties of carbide cutting tools by ceramic coating deposition

Abstract

Coating by sol–gel deposition to modify the tribological properties of K10 carbide cutting insert was performed. The study examines the thermal and tribological characteristics of uncoated cutting inserts and the cutting inserts coated with TiO2/8YSZ and TiO2/15YSZ layers respectively. The TiO2/8YSZ and TiO2/15YSZ coatings had a hardness of 1151.6 and 1678.9 HV, respectively, and the TiO2/8YSZ and TiO2/15YSZ coated inserts had scratch hardness of 2.73 and 22.98 GPa respectively. Among the uncoated and coated inserts, the TiO2/15YSZ coated inserts had the lowest coefficient of friction and rate of wear. The TiO2/8YSZ coated insert had a lower thermal conductivity when compared to TiO2/15YSZ coated insert and uncoated carbide cutting insert (10.3 vs. 14.1, and 41.8 W/m.K). The thermal expansion coefficients of the 8YSZ layers, 15YSZ layers, and carbide cutting tool were 3.66*10−6, 3.546*10−6 and 14*10−6 K−1, respectively. The reasons for the enhancement of the tribological properties of the carbide cutting tools by the ceramic coatings are discussed.

Keywords

• Ceramic coatings
• sol_gel process
• carbide cutting tool K10
• tribological properties