Cutting performance improvement of Si3N4 ceramic cutting tools by adding boride

Cutting performances of silicon nitride (Si3N4) ceramic cutting tools with and without boride additive (2.5 vol% ZrB2 or TiB2) prepared by hot-pressing at 1500 degrees C were investigated. Due to the alpha- to beta-Si3N4 phase transformation and low densification temperature, boride-containing Si3N4 ceramics with high hardness and high toughness were obtained. The turning tests showed that the effective cutting lengths of the Si3N4-2.5 vol% TiB2 ceramic (similar to 2480 m) and Si3N4-2.5 vol% ZrB2 ceramic (similar to 2200 m) were higher than the monolithic Si3N4 ceramic (similar to 1780 m). As the toughness was improved while maintaining relative high hardness, the cutting performances of the boride-containing Si3N4-based inserts were improved by adding 2.5 vol% ZrB2 or TiB2. The improved cutting performance indicated that the boride-containing Si3N4 ceramics are expected to be used in the field of ceramic cutting tools.

Automated summary

The cutting performances of Si3N4 ceramic cutting tools with and without boride additive were investigated. The addition of 2.5 vol% ZrB2 or TiB2 improved the hardness and toughness of Si3N4 ceramics. The boride-containing Si3N4 ceramic cutting tools showed higher cutting lengths compared to monolithic Si3N4 ceramic. This improvement indicates the potential use of boride-containing Si3N4 ceramics in the field of ceramic cutting tools.