EFFECT OF TiN COATED AND UNCOATED CARBIDE END MILLS ON THE MACHINING OF ST52 STEEL

Machining stands out as an essential production method in today's industry. It isfrequently preferred in the manufacturing processes of steel materials, especially those withgood machinability. Selecting parameters such as tool surface quality, cutting parameters andcooling methods under the most appropriate conditions ensures successful and efficient machining processes. Milling offers a significant advantage in the production of complex partswith multi-axis CNC machines. Improved tool materials and protective thin films allow increased performance to be achieved. Continuous microscopic examination and measurementsof tools are often required to determine tool performance and life. In addition, the surfacequality of the workpiece changes as a result of the worn tool surface. For this reason, toolperformance can be determined by surface roughness analysis on the workpiece.In this study, St52 steel workpiece was subjected to a milling process with TiN coated and uncoated carbide end mills at determined cutting parameters. St52 steel material is a preferredstructural steel in the automotive, heavy machinery, and ship construction fields with its highstrength, good toughness, and impact resistance values. Firstly, holes were drilled with Ø22mm Udril drill on the St52 steel 40x40 mm wide and 20 mm deep test samples. The millingoperation was carried out with a four-fluted (Ø12 mm diameter) helical carbide end mill. Withcoated and uncoated tools, the holes with a diameter of Ø22 mm were expanded to a diameterof Ø30 mm. Etasis Etamil VL1000 brand 3-axis CNC machine was used in the cutting process.The metal cutting process was carried out by applying the parameters of 2000 rpm speed, 100mm/min feed rate, and 0.1 mm depth of cut. The teams performed milling operations on ninedifferent workpieces. The surface roughness values obtained on each different workpiece&nbsp;were determined with the Mitutoyo Surftest SJ-201 surface profilometer. Thus, the relationship between the increasing material removal amounts of the tools and the workpiece surfaceroughness was analyzed.At the end of the entire milling process, both the cutting edge and flank surfaces of TiN-coatedand uncoated carbide end mills were examined under a Dino Lite digital microscope. Measurements were taken on the cutting tools from these images to determine the amount of wear.As a result of the experimental study, when the cutting tool wear was examined, higher wearoccurred at the tip parts of the TiN coated carbide end mill. However, the surface roughnessvalues of the workpieces machined with TiN coated carbide end mills were lower than thosewithout coating. Increasing the machining performance of steels by continuously developingthin film materials and techniques for cutting tools offers an open area for research and development.<br>