Evaluation of the Use of Vegetable Oils and Formulations as a Cutting Fluid in the Grinding of AISI 4340 Steel

Abstract

Machining processes are responsible for the manufacture of various mechanical components (screws, shafts, gears, bearings and prosthetics). However, the large volume of mineral oil-based cutting fluids consumed in machining processes causes enormous damage to the environment and human health. Therefore, this work evaluated the use of cutting fluids based on vegetable oils (soybean and corn) as a substitute for mineral cutting fluids. The physical-chemical analyses showed that the oils and cutting fluids had their viscosity changed after storage for 600 and 720 hours, indicating changes in their physical-chemical properties. The infrared spectroscopy showed possible signs of oxidation of the fluids after storage, nevertheless, did not affect their performance. The thermal analyses showed that the mineral cutting fluid degraded from (93 °C), while the corn oil (104.7 °C), corn-A5 (110.2 °C), soybean (114 °C), soybean-A5 (122.7 °C), Mix-1 (111.2 °C) and Mix-2 (107.8 °C). The machining parameters evaluated indicated that Mix-1, SN, and CR-A5 are promising candidates to replace mineral cutting fluid in the grinding of metal parts. Given the above, this study compared the physical, chemical and roughness properties of mineral cutting fluid with vegetable oils from soybean, corn and their formulations to find possible promising candidates to replace mineral oils widely used in industrial machining.