Influence of Cutting Parameters in Face Milling Semi-Solid AA 7075 Using Carbide Tool Affected the Surface Roughness and Tool Wear

The purpose of this research was to investigate the effect of the main factors on the surface roughness in semi-solid AA 7075 face milling. The results of the research could be applied in the manufacture of automotive components and mold industry. The study was conducted by using computer numerical controlled (CNC) milling machine with 63 millimeter diameters fine type carbide tool with twin cutting edge. The variable factors were the speed, feed rate and depth of cut which the bite cutter was not over 1 mm. For this experiment we used factorial designs. The result revealed that the factors affected the surface roughness were the feed rate ratio and the speed, while the depth of cut unaffected the surface roughness. Furthermore, the result of the test showed that the surface roughness was likely to reduce when using the speed 3,800 rpm and the feed rates was 1,000 mm/min. The result of the research led to the linear equation measurement value which was R-a = 0.156 - 0.000024 Speed +0.000047 Feed rate. The equation formula should be used with the speed in the range of 2,600-3,800 rpm, feed rate in the range of 1,000-1,500 mm/min and the depth of cut of not over 1 mm. When the equation was used to confirm the research results, it was found that the mean absolute percentage error (MAPE) of the surface roughness obtained from the predictive comparing to the value of the experiment was 3.62 percent, which was less than the specified error it was acceptable. Pattern of wear was similar to mechanical fatigue cracking. It may be due to the very tip of the cutting tool or an impact as cutting tool materials resistant to wear less. (C) 2014 Elsevier Ltd.