Experimental investigation of the effects of process parameters on material removal rate using Taguchi method in external cylindrical grinding operation

Abstract

Under the machining process, there are several factors which exert influence on material removal rate (MRR), including cutting condition, tool variables, machine status and workpiece variables. In the cylindrical grinding process (CGP), it is not easy to consider all process parameters that device MRR because it needs much experimentation which results in the consumption of money, time and human resources. Thus, this study investigated the impact of process parameters in external CGP for EN45 steel material using the Taguchi method. The performed experiments considered the L9 orthogonal array on a cylindrical grinding machine. The considered machining variables are the depth of cut (DOC), feed rate (FR) and work speed (WS) as response parameters before and after heat treatment processes. The heat treatment process (HTP) changed the physical and chemical properties of materials. HTP for EN45 started by heating the workpiece slowly to 650–700 °C before reaching the final temperature of 870–930 °C. Important factors for this process included the workpiece transfer facilities, quenching medium, the type of the used furnace, the size and shape of the workpiece, among others. The effect of input and output parameters was described through the “signal to noise ratio” (SNR) and “analysis of variance (ANOVA)” using Minitab® 18 software. The significant factors and the optimum cutting conditions were drawn from experiments. ANOVA table shows the impact level of the cutting depth (DOC) on MRR before heat treatment was 65.2%. Then, after the heat treatment, an essential factor for MRR of grinding was found to be the feed rate with 57.1%. The summary of the experimental results are as follows: DOC (0.025 mm), WS (270 rpm) and FR (0.02 mm). The originality of this study is based on the presence of fewer or probably no experimental investigation on the EN45 material as the workpiece that has been performed previously in optimising process parameters using the Taguchi method on external cylindrical grinding and MRR. Thus, the obtained results are important after having established the machining parameters for EN45 steel materials.