An approach to cleaner production for machining hardened steel using different cooling-lubrication conditions

Extreme thermal conditions in machining of hardened steel impair the overall performance especially the tool life and surface quality. Although, the cutting fluids are known for improving the tool life and surface quality, yet they have adverse effects on the human health as well as environment because of the presence of potentially harmful chemical ingredients. Hence, in view of the above problems associated with the cutting fluids, the implementation of sustainable methods is advantageous which further reduces the use of cutting fluids i.e. dry, minimum quantity lubrication (MQJ..) spray system and solid lubricant with compressed air cooling system. In this paper, the effect of three sustainable techniques, along with the traditional flood cooling system, on prominent machining indices such as cutting temperature, surface roughness, chip characteristics and tool wear in plain turning of hardened AISI 1060 steel has been investigated. In the end, the Pugh matrix environmental approach has been used to establish the sustainability assessment model (in terms of environmental effect, operator health, coolant cost, recycling cost and disposal, part cleaning and selected machining responses) among the used cooling/lubrication conditions. The research findings show that use of MQL system can ameliorate the heat transfer problem, and divulge quite promising results. Therefore, it is suggested that MQL system, provides environment friendliness, cleaner production and helps to improve the desirable machinability characteristics. (C) 2018 Elsevier Ltd. All rights reserved.