Application of surface modification techniques during hard turning: Present work and future prospects

Hard turning process involves machining of materials of very high hardness, and thus, the process is associated with high machining forces resulting in the generation of a large amount of heat. The prevailing machining conditions during hard turning cause high tool wear. Thus, various surface modification techniques have been adopted to reduce the friction during the hard turning process resulting in the reduction of tool wear and thereby increasing the cutting tool durability. In this context, the present review deals with the surface modification techniques adopted during hard turning applications to improve the machining performance of cutting tools. It was observed that the nanocomposite and nano-crystalline coatings excelled in machining performance among all the coatings during hard turning. Also, texturing on the surface of cutting tools resulted in the reduction of friction and thus, helped in improving the tool life of the cutting tools. Further, the present review lists various surface modification techniques and methods by identifying the research gap that can be considered for future research in hard turning.