Investigation of the solid lubrication effect of commercial boron-based compounds in end milling

Solid lubricants are environmental friendly (green) because they reduce tool wear, the usage of chemical-based cutting fluids, friction and heat during the manufacturing process. In addition, solid lubricants are reusable and easy to handle. Therefore, the solid lubricants that are required in manufacturing processes are efficient, inexpensive, and easily acquired. The present work investigates the usage of different commercial boron compounds (boric acid, boron oxide, boron pentahydrate, and Etidot-67) as lubricants and their performances regarding surface quality, cutting forces and tool wear while machining AISI 1020 steel using HSS end mills. The performance of boron compounds was studied in comparison with that of dry machining. During the metal-cutting process, constant values of the depth of cut, cutting speed and feed rate were used. In the process of milling, the cutting forces were measured with the dynamometer simultaneously. The results indicate that there is a considerable improvement in the machining performance with commercial boron compounds. As a result of using boric acid as a solid lubricant, tool wear resistance improved, the surface roughness values decreased approximately 20 to 32%, and the values of the cutting forces decreased by approximately 15 to 50% compared with dry end milling.