CORRELATION BETWEEN LEIDENFROST TEMPERATURE, COOLING CAPACITY AND MACHINING TEMPERATURE: AN EXPERIMENTAL STUDY OF CUTTING FLUIDS

Much of the energy consumed by machining materials is converted into heat, which causes several technical and economic problems for the process. The cutting fluid application by the conventional method forms a vapor film of low thermal conductivity, which prevents direct contact between the fluid and the heated surface; the so-called Leidenfrost effect, which reduces cooling efficiency. Studies of this phenomenon applied to the machining of materials are still very restricted and scarce. In this sense, the present work experimentally studied the correlation of parameters Leidenfrost temperature, cooling capacity and machining temperatures, applied to the SAE 52100 steel turning process with conventional lubri-coolant, with different cutting fluids. The thermal properties of the studied cutting fluids were taken from the technical-scientific literature. An experimental apparatus was developed for measuring and acquiring machining temperatures. Synthetic cutting fluids were shown to have a better cooling capacity, followed by semi-synthetic fluids and emulsions. There is no relationship between Leidenfrost temperature, cooling capacity, and machining temperatures for the different types of cutting fluids studied.

Application of New Techniques of Signal Processing for Detection of Wear Mechanisms in Turning of AISI 4340 Using Acoustic Emission

In this study, the short-time Fourier transform (STFT) technique was used to determine the wear mechanisms acting on uncoated and AlCrN-coated carbide tools and their variations during the machining process. To this end, tensile tests were performed on hardened AISI 4340 steel to characterize the acoustic emission (AE) signals and subsequently isolate the steel deformation and fracture mechanisms from the signs of tool wear during the steel turning. Machining tests were carried out using the following parameters: cutting speeds of 150, 200 and 250 m/min and feed rates of 0.10 and 0.20 mm/rev. The results demonstrate that AE signals in conjunction with STFT analysis can be used to identify abrasive wear, adhesive wear and other phenomena that occur during cutting.

Analysis of Machining Operation using Vegetable Oil and Nano Fluids

The influence of the hybrid additives of alumina and titanium oxide on varied lubricant characteristics as a cut fluid in steel turning. In varied volumetric concentrations, the hybrid nano lubricant has to evolve. The mixture of alumina and titanium oxide improved its tribology. The new nano-lubricant reduces the wear and nodal temperature of the tool's flank substantially. The application of hybrid nano-particles rather than nano-particles is among the most significant jobs in improving the heat transfer of fluids. We saw several sorts of pairs used to cut fluid and their effects on machining (turning).A potential MQL approach can be tested to limit the excessive use of traditional cutting fluid. The minimum amount of any cutting fluid in this approach is sprayed into the cutting zone at high pressure to improve its penetration into the machining area. Using MQL enhances surface quality and the life of the tool. MQL is a feasible alternative to wet machining. In their perspective. Therefore, both production costs and environmental dangers may be minimized through MQL..