Grinding effect of thermoplastic mold steel using green manufacturing concepts combined with various conventional wheels

Abstract

VP50 mold steel is an extremely important material for the industry, especially, to manufacture molds for extrusion and injection of thermoplastics. During the manufacturing process of molds, the grinding process is essential to ensure a high quality of surface finish and, dimensional and geometric accuracy. However, the grinding conditions can be severely critical regarding temperatures, energies, costs, and pollution, mainly in applying cutting fluids. From this perspective, technologies capable of mitigating these problems and improving the efficiency of the grinding process have been developed. The minimum quantity lubrication (MQL) technique is a potential alternative to replace the indiscriminate use of cutting fluids, for which this technique is tested in different machining conditions. Thus, to improve the characteristics of material cutting and make the process more environmentally friendly and safe. Therefore, this research aims to evaluate the grinding performance of VP50 steel using MQL compared to the flood lubri-refrigerant method. In short, it is expected that MQL will become a more sustainable and safe alternative technology for the grinding process. For this, conventional green silicon carbide (green SiC), black silicon carbide (black SiC), and aluminum oxide (Al2O3) grinding wheels were used, and three feed rates were used: 0.25, 0.50, and 0.75 mm/min. The output parameters studied were surface roughness (Ra), roundness error, diametrical wheel wear, grinding power, tangential cutting force, acoustic emission, cost analysis, CO2 emission, and SEM of active grinding wheel surface (AGWS). The results show that grinding with MQL and a green SiC grinding wheel obtained values comparable to flood method for surface roughness, representing a difference of just 11%. While the cost and CO2 emission parameters decreased by about 50% and 52.5% with the MQL technique, respectively. Thus, MQL is an economically viable and eco-friendly alternative.