MECHANISM OF CHIP FORMATION IN HIGH-SPEED TURNING OF INCONEL 718

Abstract

The mechanism of serrated chip formation during high-speed turning of Inconel 718 using PCBN cutting tools has been investigated with the aid of scanning electron microscopy and optical microscopy. A conceptual model of chip formation has been developed knowing the chip morphology. It is followed by the analysis of chip segmentation frequency and the chip forms. Further, the chip segment forms and geometry were quantitatively characterized as a function of machining parameters and the cutting edge geometry using statistical methods. The chip morphology has been correlated with the cutting forces, specific shearing energy and the resultant roughness of the machined surfaces.

Keywords:

• chip form
• chip formation
• chip thickness
• Inconel 718
• machining
• superalloy

ACKNOWLEDGEMENTS

The authors would like to acknowledge the financial support provided by Aeronautical Research and Development Board (ARDB) and the facilities provided by the DST-FIST Precision Proto-typing Cell of Mechanical Engineering Department of IIT Bombay for carrying out this work.

Notes

Present address for R. S. Pawade is Dr. Babasaheb Ambedkar Technological University, Lonere, Raigad 402 103 India.