Nanostructure of a cubic BN cutting tool material

• APT and EELS are used to show the fine microstructure in a PCBN tool material.
• The complex chemical reactions during sintering are illustrated.
• Formation of nitride, oxide and boride microcrystalline was found.

Advanced microscopy techniques, laser assisted atom probe tomography and electron energy loss spectroscopy in transmission electron microscopy are used to investigate in detail the microstructure of a polycrystalline cubic boron nitride tool material. During sintering at high pressure superhard cubic boron nitride combines with hard ceramic Ti(C,N) to form a dense material. Diffusion in Ti(C,N) and reactions between Ti(C,N), cBN and additives result in the formation of several nitride, oxide and boride phases in a complex mixed microcrystalline and nanocrystalline microstructure.