Dry machining: A step towards sustainable machining - Challenges and future directions

Manufacturing activity is a major consumer of energy and natural resources. In machining process, a large amount of heat is produced whose removal requires the use of suitable cooling agents or cutting fluids, which are a major source of waste generation and environmental damage. To eliminate hazardous cutting fluids during machining operations, researchers have tried machining components without applying cutting fluids, which is also known as dry machining. Dry machining, however, has many challenges. The aim of this paper is to present a systematic, critical, and comprehensive review of all aspects of dry machining including the sustainability aspects of machining, especially focusing on three research objectives. For the first research objective, we identify the areas where dry machining has been successfully adopted and where it has not been possible to do so. The problems and challenges arising out of dry machining and their impact on the life of the cutting tool, workpiece geometrical accuracies, the surface integrity of the workpiece, and the issues related to machinability of materials as well as machining operation specific issues have also been identified. For the second aim of this review, we report the research work carried out and various alternative solutions provided by the researchers in the area of dry machining, till the date. The period taken into consideration for the survey is the last 15 years, from the year the 2000-2015, with particular attention to the published work during the last five years. The research in this direction has been focused primarily on the application of advanced tool materials and coatings, which are resistant to high cutting temperatures frequently encountered in dry cutting, tool geometry modifications, laser or modulation-assisted machining, and minimum quantity lubrication machining. The application of this research work to carry out successful dry machining of various ferrous and non-ferrous workpiece materials and cutting in different machining operations are also discussed. The sustainability assessment of different machining processes is also discussed. For the third objective, we find gaps in the current knowledge and suggest some directions for further work to make dry machining more sustainable, profitable, and adaptable to product manufacturers. (C) 2017 Elsevier Ltd. All rights reserved.