Impact of environmental contaminants on machining properties of metalworking fluids

Increased attention to metalworking fluid (MWF) management has neglected to assess the effect of continued use on the functionality of contaminated fluids. To address this, experiments have been conducted to evaluate the lubricating, cooling, corrosion inhibition, and surface roughness functionalities of metalworking fluids subjected to both extended industrial use and contamination in a laboratory setting. The results of these experiments show no reduction in any evaluated functionality for used metalworking fluids. Metalworking fluids artificially contaminated with calcium, chloride, or hydraulic oil only exhibited reduced lubricating and cooling functionality when calcium levels were so high as to cause emulsion destabilization.