Recently, PcBN tooling have been successfully introduced in machining Ni-based superalloys, yet our knowledge of involved wear mechanisms remains limited. In this study, an in-depth investigation of PcBN tool degradation and related wear mechanisms when machining Inconel 718 was performed. Diffusional dissolution of cBN is an active wear mechanism. At high cutting speed oxidation of cBN becomes equally important. Apart from degradation, tool protection phenomena were also discovered. Oxidation of Inconel 718 resulted in formation of γ-Al₂O₃ and (Al,Cr,Ti)₃O₄ spinel that were deposited on the tool rake. Also on the rake, formation of (Ti,Nb,Cr)N takes place due to cBN-workpiece interaction. This creates a sandwich tool protection layer forming continuously as tool wear progresses. Such in operando protection enabled counterbalancing tool wear mechanisms and achieved high performance of PcBN in machining.

最近，PcBN 刀具已成功用于加工镍基高温合金，但我们对相关磨损机制的了解仍然有限。在这项研究中，对加工 Inconel 718 时 PcBN 刀具退化和相关磨损机制进行了深入研究。cBN 的扩散溶解是一种主动磨损机制。在高切削速度下，cBN 的氧化变得同样重要。除了退化，还发现了工具保护现象。Inconel 718 的氧化导致形成 γ-Al ₂ O ₃和 (Al,Cr,Ti) ₃ O ₄沉积在工具耙上的尖晶石。同样在耙子上，由于 cBN 与工件的相互作用，会形成 (Ti,Nb,Cr)N。这会随着工具磨损的进行而不断形成夹层工具保护层。这种操作保护能够平衡刀具磨损机制，并在加工中实现 PcBN 的高性能。