Chapter 3 - Experimental study on feasibility of a novel vegetable oil-based pressurized spray cooling system for sustainable surface grinding process

Abstract

Grinding is one of the most energy-intensive and high cutting fluid consuming conventional material removal processes for the manufacture of finished and semifinished parts from a wide range of engineering materials. High cutting forces and temperature generated during grinding demand huge quantity of cutting fluid for effective cooling and lubrication to prevent thermal and mechanical damages of the workpiece surface and also for extended life of the grinding wheel. However, usage and thereafter disposal of used cutting fluids, such as hydrocarbon, synthetic and semisynthetic oils, adversely affect the environment, operator’s health, and production economics. In this research, authors have developed a pressurized spray cooling system and used with vegetable oil-based cutting fluids for surface grinding of high carbon alloy steel (EN31). The objective of the research is to investigate the feasibility of the pressurized spray cooling system using vegetable oil-based metal cutting fluids with a view to enhance effectiveness of the cooling and lubrication during surface grinding for improved machinability and to minimize the amount of cutting fluid requirement for improved environment and personnel health. Experimental study has been performed using five input parameters viz. type of cutting fluids, method of fluid supply, feed rate, depth of cut, and table speed to investigate the responses of three characteristics viz. surface roughness (SR), and surface hardness (SH), and material removal rate (MRR). Three types of cutting fluids, that is, semisynthetic oil, castor oil, and palm oil-based cutting fluids have been used for three cutting fluid supply methods, that is, conventional flood cooling, low-pressure, and high-pressure spray cooling. Taguchi robust design technique with L27 orthogonal array has been designed for the experiments. Feasibility has been assessed through statistical analysis techniques like analysis of variance, Taguchi optimization, and regression analysis. The results obtained indicate that Palm oil with high-pressure spray cooling system produced the optimal SR 0.68µm and SH 195.4 HV. Castor oil with high-pressure spray system produced optimal MRR 232.55mm3/min. The developed regression models have good predictability of the responses with a mean error of less than 5% over wide range of parameter values. The results of parametric study have shown close similarity with the statistical results. The results of the present work suggest that vegetable oil-based pressurized spray cooling methods have significant potential to be used as effective cooling and lubrication method for surface grinding process for the improved sustainability.