An Experimental Investigation on the Effects of MQL Method on Grinding of Nickel Based Superalloy 738 (Inconel 738)

In this research, the usage possibility of minimum quantity lubrication in grinding super alloy Inconel 738 has been studied empirically to reach improved grinding and lubricating conditions. For reaching this purpose, based on Taguchi design of experiment method grinding variables were set in three levels and lubrications were set in six levels in order to compare conventional, dry and MQL methods. Studies have shown that in grinding this material by MQL method we can obtain the results very close to conventional mode in terms of force and surface roughness even having better surface quality. Results in MQL method by considering various oils with different viscosities show that Behzist 6046 and Canola herbal-based oil are the best replacement of conventional method in terms of force reduction and surface roughness. In fact, in the case of using the MQL method together with Behzist 6046 oil, a 50% reduction in the force output is observed and when using Behzist 6043 oil, there is only a 30% difference in the surface roughness obtained with the traditional method, which creates a better surface smoothness is visible. For all the 100 investigated modes, the results show that the optimal levels for the variables of advance speed, stone wheel speed and chipping depth are level 1, 2046 rpm and 5 microns, respectively. The specific vertical force can be predicted in more than 50% of the tests with the least error (about 20%).