What is it about?

In this research, the tool-chip interface temperature (TCTI), the tool temperature (TT) and the average surface roughness (Ra) were measured experimentally during the turning of AISI 4140 alloy steel with TiAlN-TiN, PVD-coated tungsten carbide inserts using an IR pyrometer technique, a K-type thermocouple and a portable surface-roughnessmeasurement device, respectively. The workpiece material was heat treated by an induction-hardening process and hardened up to a value of 50 HRC. The Taguchi method L18 (21 × 37) was used for the determination of the optimum control factors. The depth of cut, the cutting speed and the feed rate were taken as control factors. The analysis of variance was applied in order to determine the effects of the control factors on the tool-chip interface temperature, the tool temperature and the surface roughness.

Featured Image

Why is it important?

In order to overcome the difficulties in terms of efficiency and the quality of production encountered in the metal-cutting industries, all the stages of the machining process need to be monitored. During the metal-cutting processes, one of the key factors is the cutting temperature, which directly affects the surface quality, the tool wear, the tool life, and the cost of production. Temperature monitoring is one of the most difficultand complicated procedures in metal-cutting operations. It is extremely complex to develop a model formeasuring the temperature due to the complexity of the different events at the point of contact between the tool and the workpiece. Therefore, an accurate and repeatable temperature prediction still remains as a challenge due to this complexity of the contact phenomenon. It is quite difficult to measure the temperature since the heat in the region is very close to the cutting edge. Due to a lack of sufficient experimental data, it is not possible to verify a mathematical model. Numerous attempts have been made to measure the temperature during machining ope-rations. Amongst the many experimental methods to measure the temperature directly, only a few systems have used the temperature as an indicator of machine performance and for industrial applications. Therefore, the temperature can be controlled using the appropriate cutting parameters to design and develop the system and it will be beneficial to increase the efficiency in production.


The tool-chip interface temperature increased significantly depending on the increase of the cutting speed. The depths of cut and feed rate do not have a significant effect on the tool-chip interface temperature. The tool temperature increased significantly depending on the increase of the depth of cut. The surface roughness increased depending on the increase of the feed rate, while the same tendency was not observed for the depth of cut and the cutting speed. The correlation coefficients of the predictive equations developed for the estimation of the minimum tool-chip interface temperature, the tool temperature and the surface roughness by multiple linear regression analysis were calculated as 0.928, 0.681 and 0.826, respectively. Higher correlation coefficients reflect the reliability of the developed equations. The mean of the % error ratios of the estimated results obtained by Taguchi method and the predictive equations were less than 14 %. This reflects the reliability of the statistical analyses.

Prof.Dr. Ali Riza Motorcu
Canakkale Onsekiz Mart Universitesi

Read the Original

This page is a summary of: Analysis of the cutting temperature and surface roughness during the orthogonal machining of AISI 4140 alloy steel via the Taguchi method, Materiali in tehnologije, June 2016, Institute of Metals and Technology,
DOI: 10.17222/mit.2015.021.
You can read the full text:



The following have contributed to this page