Effect of hardened steel grinding applying MQL with diluted cutting fluid and wheel cleaning jet using a vortex system for air cooling

• Grant number: 20/14296-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2021
• Effective date (End): December 31, 2021
• Field of knowledge: Engineering - Mechanical Engineering - Manufacturing Processes
• Principal Investigator: Eduardo Carlos Bianchi
• Grantee: Douglas Maiochi Daniel
• Host Institution: Faculdade de Engenharia (FE). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

The demand for the development of new products, combined with high precision and sustainability of its manufacturing process is growing within the metal-mechanical industry. Thus, AISI 4340 steel has been one of the most requested materials in areas such as aeronautics and automobilistic, due to its properties of high mechanical strength, toughness and resistance to fatigue. In search of more ecological ways of machining this material within the industry, with the objective of generating and using less harmful residues to the environment and workers, we have the technique of the minimum quantity lubrication (MQL) as an alternative to conventional cutting fluids as lubricant-refrigerant method. MQL uses a small amount of fluids, making it a more sustainable way than refrigerants in abundance. However, the use of the technique in precision grinding needs to be improved, with regard to its ability to clean the cutting zone and to dissipate the heat generated by the system in the process. Thus, in this work, the use of MQL diluted in water in the grinding will be carried out, which will be combined in two techniques. The first being adopted MQL in the refrigerated form, through an auxiliary cooling system built into the MQL compressed air. In the second case, the MQL dilution will be aided by a cooled wheel cleaning system, both acting individually and combining its benefits in search of greater lubrication-cooling and system cleaning efficiency. Also, these techniques will be compared to the fluid-in-abundance method to verify their actual capabilities. In addition, in order to obtain a better quality of finishing of the part to be machined, the method will be combined with the use of a superabrasive wheel of CBN (Cubic Boron Nitride) as a cutting tool. To carry out the analysis of the grinding process, the output variables used in this research will be: surface roughness, roundness deviation, diametrical wheel wear, tangential cutting force, acoustic emission, microhardness and optical microscopy.