Performance of cermet tools with negative rake angles during high speed machining

Abstract

The development of cutting tool materials has been achieved mostly through practical machining operations. Cermets have been used as cutting tools materials for many years. This is due to improvement made on the cermet grades, its stability, speeds and conditions as well as the trend towards near-to-finish workpiece blanks. This research is to investigate performance of cermet insert under different rake angles and different cutting speed. Experiments were carried out by using cermet (CT5015). Different rake angles have been applied in the experiments which are 0o, -3o, -6o, -9o and -12o respectively. Cutting speeds 1000 m/min and 300 m/min with feed rate 800 mm/min and 240 mm/min have been applied. Depths of cut were kept constant throughout the experiments. Data were collected from measurement of every single pass of cutting, surface roughness, tool wear, cutting force and cutting temperature. The experimental results showed that increasing negative rake angles causes higher wear, shorter duration of tool life and poor surface finish. Temperature trend increases by increasing the negative rake angle. The different between high speed and conventional speed was also observed in this experiment. High speed turning gives shorter tool life, high wear rate but finer surface finish than conventional one.