Hard cutting process, the cutting force is a measure of the main factors in the overall process stability and machining precision. Ca6140 lathe tests carried out with a continuously variable transmission, the use of strain measurement Turning dynamometer cutting force, cutting temperature measurement using natural thermocouple method, the workpiece material selection gcr15 bearing steel, hrc30 obtained by the heat treatment process, hrc40, hrc50, hrc60 and hrc64 total of five kinds of hardness of the specimen.
Since brittle pcbn tool material, generally required before use large obtuse (200 ~ 400μm) and the chamfer processing, during the cutting process, since the depth of cut and feed rate are small, blunt and negative chamfer actually mainly involved cutting part. Cutting area influenced by the shape of the cutting tool when pcbn gcr15 hardened bearing steel radial force fy is usually the largest, followed by the main cutting force fz and axial forces fx, and cutting force in the rough about finishing 6-9 times. Hard CUTTING PROCESS almost the feed rate, depth of cut and flank wear a linear relationship. When cutting speed increases, the cutting force decreased slightly, mainly because of the cutting of the workpiece temperature was increased ductility increased, but the nature of this change corresponds to only a certain cutting speed range. When the contact angle is small and the depth of cut smaller radial force fy very large and exceeds the main cutting force fz, cutting conditions at this time are relatively poor, can lead to quench cracking tool, should increase the amount of feed to improve this poor cutting condition.