Eco-friendly machining of advanced ceramics: wheel cleaning jet for greenhouse gas reduction

Abstract

The constant development of new materials, such as ceramics with high wear resistance, makes it necessary to adapt machining processes by creating new methods or improving existing ones. Moreover, grinding is widely used as a finishing process in workpieces since it provides excellent surface roughness and dimensional tolerances. Due to the high volume of cutting fluid used in conventional lubrication (flood), associated with harmful effects such as contamination and intoxication, alternative methods have become highly necessary. The minimum quantity lubrication (MQL) technique reduces fluid use but has low cooling capacity, in addition to barely removing chips, making it essential to seek improvements to make it competitive. In this sense, adding water to the MQL can improve the cooling capacity at the cost of reducing lubrication. At the same time, applying a wheel cleaning jet (WCJ) of compressed air assists in chip removal. Thus, this work aims to analyze the results of external cylindrical grinding of alumina (Al2O3) using a synthetic diamond grinding wheel, comparing the techniques of conventional MQL, diluted MQL, and MQL + WCJ against the flood method. Surface roughness, roundness deviation, diametrical wheel wear, G ratio, grinding power, tangential cutting force, grinding cost analyses, and CO2 pollution emission were conducted for this. The results show that adding water to MQL, associated with WCJ, significantly improved roughness, wear, and grinding power. Furthermore, the analysis of costs and pollution showed that using MQL significantly reduced costs and CO2 emissions, proving the socio-environmental advantage of the MQL method against the flood method.