This study was carried out to investigate the surface roughness in infeed centerless grinding process. The experiment was performed to determine the influence of several technological parameters on the surface roughness. The grinding wheel of Hai Duong Company, Vietnam, was used to machine the SCM435 steel. The experimental matrix was designed using central composite design (CCD). The machining parameters that were used as the input parameters in this study include the workpiece center height, dressing feed rate, regulating wheel velocity, and infeed rate. From the experimental data, an initial model of the surface roughness was built as a quadratic function. Further, a Box-Cox transformation was used to develop a new model from the initial surface roughness data with better accuracy than that of the initial model. The accuracy of the proposed model was verified by comparing the values of the mean absolute error, mean square error, and determination coefficients. This direct approach can be applied for the investigation of other factors during machining processes and can be used in the optimization of machining processes.

1. [1] I. D. Marinescu, M. P. Hitchiner, E. Uhlmann, W. B. Rowe, and I. Inasaki, “Handbook of machining with grinding wheels,” CRC Press, 2006.
2. [2] S. Malkin and C. Guo, “Grinding technology – Theory and application of machining with abrasives (2nd edition),” Industrial Press, 2008.
3. [3] F. Hashimoto, I. Gallego, J. F. G. Oliveir, D. Barrenetxea, M. Takahashi, K. Sakakibara, H.-O. Stalfelt, G. Staadt, and K. Ogawa, “Advances in centerless grinding technology,” CIRP Annals – Manufacturing Technology, Vol.61, pp. 747-770, 2012.
4. [4] S. Dzebo, J. B. Morehouse, and S. N. Melkote, “A methodology for economic optimization of process parameters in centerless grinding,” Machining Science and Technology: An Int. J., Vol.16, No.3, pp. 355-379, 2012.
5. [5] Y. Wu, Y. Fan, and M. Kato, “A feasibility study of microscale fabrication by ultrasonic-shoe centerless grinding,” Precision Engineering, Vol.30, pp. 201-210, 2006.
6. [6] Y. Wu, Y. Fan, M. Kato, J. Wang, K. Syoji, and T. Kuriyagawa, “A New Centerless Grinding Technique without Employing Regulating Wheel,” Key Engineering Materials, Vols.238-239, pp. 355-360, 2003.
7. [7] W. Xua and Y. Wu, “A new in-feed centerless grinding technique using a surface grinder,” J. of Materials Processing Technology, Vol.211, pp. 141-149, 2011.
8. [8] W. Xu, Y. Wu, T. Sato, and W. Lin, “Effects of process parameters on workpiece roundness in tangential-feed centerless grinding using a surface grinder,” J. of Materials Processing Technology, Vol.210, pp. 759-766, 2010.
9. [9] W. Xu and Y. Wu, “Simulation investigation of through-feed centerless grinding process performed on a surface grinder,” J. of Materials Processing Technology, Vol.212, pp. 927-935, 2012.
10. [10] K. Ohashi, K. Tan, T. Ashida, and S. Tsukamoto, “Quick On-Machine Measurement of Ground Surface Finish Available for Mass Production Cylindrical Grinding Process,” Int. J. Automation Technol., Vol.9, No.2, pp. 176-183, 2015.
11. [11] Y. Takaya, “In-Process and On-Machine Measurement of Machining Accuracy for Process and Product Quality Management: A Review,” Int. J. Automation Technol., Vol.8, No.1, pp. 4-19, 2014.
12. [12] J. Kopac, P. Krajnik, and J. M. d’Aniceto, “Grinding analysis based on the matrix experiment,” Proc. 13th Int. Scientific Conf. on Achievements in Mechanical and Materials Engineering, pp. 332-334, 2005.
13. [13] P. Krajnik, J. Kopac, and A. Sluga, “Design of grinding factors based on response surface methodology,” J. of Materials Processing Technology, Vols.162-163, pp. 629-636, 2005.
14. [14] P. Krajnik, A. Sluga, and J. Kopac, “Radial basis function simulation and metamodelling of surface roughness in centreless grinding,” J. of Achievements in Materials and Manufacturing Engineering, Vol 14, No.12, pp. 104-110, 2006.
15. [15] A. N. Siddiquee, Z. A. Khan, and Z. Mallick, “Grey relational analysis coupled with principal component analysis for optimisation design of the process parameters in in-feed centreless cylindrical grinding,” Int. J. Adv. Manuf. Technol., Vol.46, pp. 983-992, 2010.
16. [16] Z. A. Khan, A. N. Siddiquee, and M. H. Sheikh, “Selection of optimal condition for finishing of centreless-cylindrical ground parts using grey relational and principal component analyses,” Int. J. of Materials and Product Technology, Vol.43, No.1/4, pp. 2-21, 2012.
17. [17] P. B. Khoi, D. D. Trung, and N. Cuong, “A study on multi – objective optimization of plunge centerless grinding process,” Int. J. of Mechanical Engineering and Technology, Vol.5, No.11, pp. 140-152, 2014.
18. [18] D. D. Trung, N. Cuong, P. B. Khoi, and T. Q. Hung, “Application of Generalized Reduced Gradient Method for Optimization of Plunge Centerless Grinding Process,” Int. J. of Scientific Research in Science, Engineering and Technology, Vol.1, Issue 2, pp. 368-372, 2015.
19. [19] N. V. Du and N. D. Binh, “Design of experiment techniques,” Science and Technics Publishing House, 2011 (in Vietnamese).
20. [20] https://ncss-wpengine.netdna-ssl.com/wp-content/themes/ncss/pdf/Procedures/NCSS/Box-Cox_Transformation.pdf [Accessed June 1, 2020]
21. [21] https://www.statisticshowto.com/absolute-error/ [Accessed June 1, 2020]
22. [22] https://byjus.com/maths/mean-squared-error/ [Accessed June 1, 2020]