This research discusses the effect of negative rake angle, to the temperature and tool wear on rock cutting. The cutting process was conducted on marble rock material, without coolants and utilized tungsten carbide inserts with 0o, -5o, -10o, -15o, -25o, -30o and -40o rake angles; meanwhile, the feed rate, spindle speed and depth of cut were applied constantly. Temperature measurement used K-type thermocouples, and the scanning electron microscope observed the tool wear. The data collection was monitored in real time from initial conditions until cutting 150 mm in length. The tool wear data was observed after the turning process of 150 mm in length. The results show that at negative rake angle -25o produce the smallest temperature and tool wear compared to other negative rake angles. This phenomenon occurs because the cutting mode changes from brittle cutting mode to ductile cutting mode. The pile of chip powder in front of the cutting tool was implemented to protect the cutting tool from direct friction with the workpiece and enhance thrust force on the surface of the marble rock. It would greatly affect the cutting temperature and tool wear.
Science Journal 