Evaluation of the oil flow using the MQL technique applied in the cylindrical plunge grinding of AISI 4340 steel with cbn grinding wheel

Abstract

The grinding process is defined as an abrasive cutting action of a tool known as grinding wheel, which is submitted to high rotations, promoting excellent finishing and accuracy in dimensions, respecting the parameters established in each project. During the machining, the cutting edges of the abrasive grains undergo wearing and this increases the contact surface of the tool with the workpiece, increasing the machining temperature and creating possibilities of damaging it. Therefore, it is necessary to use a cutting fluid, responsible for lubricating and cooling the cutting zone, removing the chips from the cutting region between the workpiece and the wheel, and even having an anticorrosive action. However, its composition causes contamination to the environment and to the operator. In face of the increasingly strict environmental laws, it has become necessary to search for new methods of cooling that are at least as effective as conventional one and economically practicable. Thus, the Minimum Quantity of Lubrication was developed as a mist of air and oil applied at high pressure, reducing drastically the use of contaminants. In this work, two oil flows were used for the MQL technique, 30 ml/h and 120 ml/h. The wheel used was a CBN (Boron Cubic Nitride) one, composed of synthetic grains and the workpiece, in a ring format, were produced in AISI 4340 steel quenched and tempered. It was observed from results that MQL can be applied in the industrial processes without losing piece quality. keywords: cylindrical plunge grinding, minimum quantity of lubrication, cubic boron nitride grinding wheel, AISI 4340 steel.

Potential of Bio-Metal Cutting Fluid from Treated Recycled Cooking Oil for Metal Cutting Fluid Application

“…In fact, according to Sharma [18], the optimum value of the MQL mist pressure and spraying distance plays a major role that affect the machinability of the milling process. In this research, the flow rate of cutting fluid was set up to 60 ml/hr using two nozzles which can be sum up to 120 ml/hr This flow rate is based on the optimum value from the previous study by [19]- [21]. To ensure sufficient 60 ml/hr of cutting fluid were channeled to the cutting zone, the pulse generator from the MQL's control valve was set to 24 pulses/min, and samples of the dispersed cutting fluid were collected using an empty measuring beaker in one hour.…”