Eventos Anais de eventos
COBEF 2023
12th Brazilian Congress on Manufacturing Engineering
THE INFLUENCE OF BASE FLUID AND GRAPHENE NANOPARTICLES CONCENTRATION ON SURFACE INTEGRITY OF SAE 52100 STEEL AFTER GRINDING
Submission Author:
Raphael Lima de Paiva , PI
Co-Authors:
Raphael Lima de Paiva, Déborah de Oliveira, Rosemar Batista da Silva
Presenter: Raphael Lima de Paiva
doi://10.26678/ABCM.COBEF2023.COF23-0489
Abstract
Grinding is known as a high specific energy process, in which most of it is transformed into heat and conducted to the workpiece, especially when using conventional abrasives like aluminum oxide and silicon carbide. Thus, the use of cutting fluid is indispensable to attenuate or avoid the occurrence of thermal damage. However, concerning human health and the environment, as well as economic aspects and the search for more sustainable processes, strategies that reduce cutting fluid usage such as the minimum quantity lubrication (MQL) technique have gained prominence. This technique uses a much lower quantity of cutting fluid than flood (conventional coolant delivery technique), which is directed to the cutting zone with compressed air. Nevertheless, although the MQL technique has shown promising results in comparison to dry grinding and flood technique for different materials, the use of nanofluids has been showing great potential to improve the MQL technique, since the presence of nanoparticles tends to improve lubrication and cooling capacities of the base fluid. In this sense, this work aims to evaluate the influence of the type of base fluid and nanoparticles concentration on the surface integrity of SAE 52100 hardened steel after grinding with graphene-based nanofluids applied with the MQL technique. Two different base fluids were tested: a semi-synthetic vegetable base and a synthetic one. The graphene was added to the base fluids at two different concentrations: 0.025 wt.% and 0.075 wt.%. Grinding trials using the base fluids only (without nanoparticles) were also performed for comparison purposes. The surface integrity of the workpiece after grinding was analyzed in terms of surface finish (Rq parameter) and microhardness below the machined surface. The results showed that the nanofluid’s efficiency in reducing the surface roughness of the ground surface was strongly influenced by the base fluid and graphene concentration: best results (8.6% reduction in Rq roughness compared to the traditional MQL technique) were found after grinding with combination between semi-synthetic fluid and the lowest graphene concentration (0.025 wt.%). Additionally, the presence of graphene in the cutting fluid attenuated the occurrence of thermal damage in terms of microhardness reduction; for the highest nanoparticles concentration (0.075 wt.%), such reductions were only 1% and 3% after grinding with semi-synthetic and synthetic fluid, respectively.
Keywords
Grinding, Nanofluids, Semi-synthetic fluid, graphene, MQL technique, surface integrity, Thermal damage
