Yahya Isik

Thermocouple and Infrared Sensor-Based Measurement of Temperature Distribution in Metal Cutting

In metal cutting, the magnitude of the temperature at the tool-chip interface is a function of the cutting parameters. This temperature directly affects production; therefore, increased research on the role of cutting temperatures can lead to improved machining operations. In this study, tool temperature was estimated by simultaneous temperature measurement employing both a K-type thermocouple and an infrared radiation (IR) pyrometer to measure the tool-chip interface temperature. Due to the complexity of the machining processes, the integration of different measuring techniques was necessary in order to obtain consistent temperature data. The thermal analysis results were compared via the ANSYS finite element method. Experiments were carried out in dry machining using workpiece material of AISI 4140 alloy steel that was heat treated by an induction process to a hardness of 50 HRC. A PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. The results showed that with increasing cutting speed, feed rate and depth of cut, the tool temperature increased; the cutting speed was found to be the most effective parameter in assessing the temperature rise. The heat distribution of the cutting tool, tool-chip interface and workpiece provided effective and useful data for the optimization of selected cutting parameters during orthogonal machining.

Using internally cooled cutting tools in the machining of difficult-to-cut materials based on Waspaloy

Nickel-based superalloys such as Waspaloy are used for engine components and in the nuclear industry, where considerable strength and corrosion resistance at high operating temperatures are called for. These characteristics of such alloys cause increases in cutting temperature and resultant tool damage, even at low cutting speeds and low feed rates. Thus, they are classified as difficult-to-cut materials. This article presents a cooling method to be used in metal cutting based on a tool holder with a closed internal cooling system with cooling fluid circulating inside. Hence, a green cooling method that does not harm the environment and is efficient in removing heat from the cutting zone was developed. A series of cutting experiments were conducted to investigate the practicality and effectiveness of the internally cooled tool model. The developed system achieved up to 13% better surface quality than with dry machining, and tool life was extended by 12%. The results clearly showed that with the reduced cutting temperature of the internal cooling, it was possible to control the temperature and thus prevent reaching the critical cutting temperature during the turning process, which is vitally important in extending tool life during the processing of Waspaloy.

Influence of cutting parameters on the chip-tool interface temperature during the turning of Waspaloy

Abstract Waspaloy, as a nickel superalloy, is a difficult-to-machine material used for gas turbine engine components that require considerable strength and corrosion resistance at high operating temperatures. The machining of nickel-based alloys generates high temperatures at the cutting tool edge. This research investigated the relationship between cutting parameters and cutting temperature, using a remote temperature measurement method employing an infrared thermometer. In addition, the effects of cutting parameters on surface roughness were examined. Experiments were conducted on Waspaloy AMS5708 superalloy samples and a PVD TiAlN-TiN-coated WNVG 080404-IC907 carbide insert was used during the turning process. It was observed that the highest cutting speed and highest feed rate generated higher temperatures and higher surface roughness. Better surface roughness was obtained with the lowest feed rate, the highest cutting speed and the higher cutting depth. No cutting fluid was used in the experiments.

Tool life and performance comparison of coated tools in metal cutting

The objective of the present work is to assess the effect of different coating materials on machinability in the turning of AISI 1050 steel. The cutting tools used in this research are PVD coated TiAlN, and CVD coated TiC + TiCN + TiN, TiC + AI2O3 + TiN and TiN + TiCN + TiN inserts (ISO P25). The type of inserts is DNMG 150608. During the experiments cutting forces, and flank wear values were measured throughout the tool life. The machining performance of different coating materials was evaluated. In addition, cost analysis based on total machining cost per part was performed for the comparison of the economic viability between the different coating materials.