Comparison of the effects of vegetable oils such as castor and canola oil and polyol esters on the metalworking performance of al 6061 and al 7075 metal alloys by tapping torque method

Abstract

Machinability of aluminum alloys still represents a challenge due to its tendency to staining and there is a great need for the development of sustainable solutions for lubrication and cooling. Therefore, researchers are performing intensively to obtain an effective way of machining such alloys. Growth of aerospace and automotive industries have increased utilization of these alloys day by day. Working for the development of more economical and environmentally friendly production technologies has gained increased interest to reduce the environmental and health risks and cost factor caused by the widely used flood lubrication. Vegetable oil and polyol esters are biodegradable synthetic base fluids that can be used as a sustainable alternative to petroleum-derived oils in many lubricant applications. In this study, the effects of castor and canola oils and trimethylolpropane trioleate (TMPTO) and trimethylolpropane trioleate complex (TMPCX), neopentyl glycol (NPG) and pentaerythritol tetra-oleate (PE-TO) type polyol esters on the machining performance of Al 6061 and Al 7075 alloys were investigated using the Tapping Torque test method. As a result, in the studies performed with neat fluids, it was determined that PE-TO showed the best performance in Al 6061, while TMP-TO showed the best performance in Al 7075. In addition, it was found that both vegetable oil types showed lower metal working performance than polyol esters in both alloys. Since similar results were obtained in the machining of both alloys, 68% emulsions were formulated with these vegetable oils and polyol esters to compare the machining performance. In contrast to neat machining, On Al 6061, PE-TO showed the most dramatic performance, while canola oil showed the highest performance. Since Al 7075 has harder machining conditions than Al 6061, the emulsion machining performance of Al 7075 alloy improved with the cooling effect of water and gave better results than neat machining. © 2023 Elsevier B.V., All rights reserved.