Optimization of Process parameters on Surface Quality and Micro Hardness in Dry Turning of AZ61 Magnesium Alloy Using Taguchi Method and Regression Analysis

Abstract This article investigated the dry orthogonal turning performance on an 80 mm circular bar of AZ61 magnesium alloy with the perspective of optimizing the turning process parameters for better responses, such as surface roughness and the hardness variation in the micro level of the work. The turning process is carried out with standard insert CNMG120408 on a conventional center lathe. The machining input parameters implied at three levels such as spindle speed 500-1200 rpm, feed rate 0.1 - 0.31 mm/rev and depth of cut 0.4-1.2 mm. The output of the turning process, such as surface unevenness and micro hardness, were assessed with a surface tester Mitutoyo SJ301 and SE1000DT Vickers’s hardness machine. The Taguchi-based experimental layout (L27) is employed to identify the outcome of machining factors on surface roughness and the hardness of work. The responses are recorded, and optimization is evaluated using regression and ANOVA to assess the noteworthy factors for the better responses. ANOVA showed feed rate contributed 36.5% to Ra and the interacted factors feed rate and depth of cut contributed 27.5% to Vickers hardness at 95% confidence. The result indicates that the machining parameters are considerably influenced by both the quality of the surface finish and the hardness of the alloy, such that a lower feed rate leads to a good surface finish and minimal variation in hardness.