Analysis and Effect of Cutting Parameters on The Surface Roughness of Type 4140 Steel in The Dry Milling Process

Abstract

Currently in the world of metal cutting industry, wet machining is still carried out and machining experts continue to strive to reduce the use of coolant so that benefits can be obtained from economic, environmental and operator safety aspects. One of the criteria for determining machining quality is surface roughness. Surface roughness is influenced by machining parameters such as cutting speed, feed depth and feed rate as independent variables. The aim of the research is to obtain surface roughness values ​​for type 4140 steel workpieces due to spindle rotation speed and feed depth, which uses a carbide endmill as a cutting tool. Research activities were carried out with 9 specimens each for dry machining and wet machining using variations in machine spindle rotation of 1200 rpm, 1400 rpm and 1600 rpm with feed depths of 0.5 mm, 0.75 mm, 1 mm. Data processing uses the statics method with a normal distribution curve to obtain surface roughness data. To determine the roughness value of the machined surface, it is tested using a Surface Test measuring instrument. The surface roughness obtained from machining under optimum conditions for dry machining is 1.699 µm, 2.778 µm and 2.868 µm at a machine spindle rotation of 1600 rpm. while those carried out using wet machining obtained respective results of 1.602 µm, 2.654 µm and 2.815 µm at a machine spindle rotation of 1600 rpm. So optimum cutting/slicing is obtained at a spindle rotation speed of 1600 rpm with Ra = 1.699 µm for dry machining while for wet machining the surface roughness value Ra = 1.602 µm is obtained at a spindle rotation speed of 1600 rpm. The comparison of the results of dry machining (Ra= 1.699 µm) and wet machining (Ra= 1.602 µm) to obtain the most optimum Ra surface roughness value is not significant, so it is a good opportunity that dry machining technology can be applied to the metal cutting industry although Until now, many people still use wet machining processes using cutting fluids to cut steel meta