Investigation of the Cutting Performance of Cutting Tools Coated With the Thermo-Reactive Diffusion (TRD) Technique

The life of cutting tools used in metal cutting operations is limited due to wear. Therefore, increasing wear resistance is of great importance for minimizing economic losses. By using different coating techniques, tools may be coated with harder compounds for enhancing wear resistance. Tool hardness and toughness are also increased through coating. In this study, boron and titanium coatings were applied on round cutting tool surfaces made of AISI D2 and AISI M2 steels by the thermo-reactive diffusion technique. AISI D2 cutting tool surface was coated with boron at 950 °C for 1 hour, and AISI M2 cutting tool surface was coated with boron at 1000 °C for 1 hour. After boron coating, the surfaces of the samples were coated with titanium at 1050 °C for 1 hour. The coated samples were characterized by using SEM, X-ray diffraction, EDS analysis, and micro hardness tests. Machining tests were performed to observe the wear resistance of the samples and the roughness of the machined surface. Machining tests were carried out on DIN 1651 free-cutting steel. Cylindrical turning tests were run at three different cutting speeds, 38, 73, and 138 m/min. and at three different feeding values, 0.08, 0.12, and 0.16 mm/rev. The results showed that the boron- and titanium-coated tools performed 50% better than the just boron-coated tools. In terms of surface roughness, it was determined that there was no significant difference between the coated and uncoated tools. The cutting performance values of our coating method were compared to those of ISCAR brand RCMT (code of the insert used in turning and milling operations in the ISO norm) inserts coated with the PVD and CVD methods, and it was seen in the experimental results that the tool coated with the TRD method performed better.