A new formulation of cubic boron nitride could provide a more solid alternative to cemented carbide as finish-machining becomes more demanding.
Although carbide inserts are proven performers in virtually all types of CNC machining, aerospace alloy finishing presents a particularly good opportunity to start exploring alternatives. In recent testing, a new type of cubic boron nitride (CBN) finish-turning insert ran three times faster, lasted three times longer and removed nine times the material as cemented carbide in titanium 6AL-4V, all on the same cutting edge. “Consistent chip control and a long-lasting edge make this a great candidate to replace current stable finishing processes using carbide,” the researchers wrote.
The primary difference between this CBN and other inserts is not what it contains, but what it lacks: a binder to hold the sintered material together. Rather, the nanoparticles are fused directly to one another to form a virtually solid, continuous cutting surface. This construction enables taking full advantage of CBN’s extreme hardness and thermal conductivity in a material that is notorious for work hardening.