Use of Boric Acid Powder Aided Vegetable Oil Lubricant in Turning AISI 431 Steel

There has been a great demand for environmentally benign lubricant due to stricter regulation imposed on the use of conventional lubricant made from mineral oils, as it is not safe to the health of workers and to the environment. Following to this, vegetable oil as based lubricant offers the suitable solution for an environmentally friendly lubricant as it is non-toxic and biodegradable. Furthermore, the performance of vegetable oil base lubricant can be enhanced by adding micro/nano-particle with the lubricant. The present study focus on the use and the performance of boric acid powder with palm kernel oil in comparison to conventional oil as a means of lubrication in machining AISI 431 steel with minimum quantity lubrication. A 24 full factorial design of experiment has been conducted with cutting speed, feed rate, depth of cut and types of lubricant as the input process variables. Surface finish has been evaluated in each of the machining conditions. It has been found that the feed rate and type of lubricant are the only factors that have significant effect on the surface finish and boric acid powder aided lubricant machining outperformed conventional lubricant. The average improvement in surface finish with boric acid powder aided vegetable oil lubrication is observed to be 7.21%. The cutting speed and depth of cut apparently do not have any significant effect on surface roughness in minimum quantity lubrication, of conventional and vegetable oil on lubrication.