Influence of grinding parameters on surface roughness and temperature under carbon nanotube assisted MQL

Conventional flood cooling system has some environmental and economic issues. Minimum quantity lubrication (MQL) has been established as a better strategy to control the machining temperature than conventional flood cooling system. Integrated use of carbon nanotube (CNT) with MQL has been drawing attention in recent times. The purpose was to study the effects of hard grinding with key focus on temperature, surface roughness and chips morphology under the application of CNT-mixed MQL and compressed air. The hardness of work material (AISI 1060 steel) was varied at three values (40, 45 and 50 HRC) with the variation of fluid flow rates and infeed rates to observe the machining behaviour. Experimental plan was established using full factorial design of experiment while mathematical models and optimisation were constructed following response surface methodology (RSM). Optimum output responses were flow rate 75 ml/h, infeed (depth of cut) 10 mu m and hardness of material is from 40 to 45 HRC. Fluid flow rate of 75 ml/h resulted in best surface finish while work material of 40 HRC hardness generated lowest temperature while machining. A lower hardness values and a moderate flow rate produced favourable machining outcomes, i.e. lower temperature and improved surface finish.