پوشش CBN-TiNکامپوزیتی: سنتز و تجزیه و تحلیل عملکرد

Cubic boron nitride (CBN) coating, due to its promising properties, is under development worldwide for machining and other related applications. To synthesize a continuous CBN coating by conventional vapor deposition methods (CVD/PVD), however, poses many challenges, such as metastable CBN phase stabilization, as well as the high levels of intrinsic stress developed during the growth. A novel combinatorial approach, which is under development in an effort to develop a CBN composite coating for cutting tools, is reported in this paper. The approach involves a two-step process consisting of electrostatic spray coating (ESC) of CBN particles, followed by chemical vapor infiltration (CVI) of TiN. The process is optimized to deposit a CBN-TiN composite coating with a thickness in excess of 10 μm on tungsten carbide inserts. Such coated tools have been successfully evaluated and tested for machining applications. For production on a commercial scale, the laboratory systems have been upgraded to industrial size. The outcome of scaling up from an experimental to an industrial-sized unit is reported in this paper. The industrial electrostatic spray coating unit, which can coat a batch of about 50 inserts in a couple of minutes, is currently being field tested.