In this study, in order to confirm the machining characteristics of AISI 1020 CD-Bar, cutting was performed after strength measurement, and surface roughness analysis was performed according to cutting conditions. Tensile strength was reduced by about 27.7% compared to AISI 1045 material, and Rockwell hardness HRC was reduced by 46.7%. The surface roughness measurement after cutting was divided into roughing, semi-finishing and finishing turning. In particular, in finishing machining, the best surface roughness was confirmed when the cutting speed was 150m/min and the depth of cut was 0.6mm based on the feed rate of 0.05mm/rev.

Recently, halogen lamps for vehicle exterior lamp systems are being replaced by LEDs (Light Emitting Diode) in consideration of miniaturization, power consumption, life, luminance, and eco-friendliness. Due to regulations on the amount of light required, luminance, light uniformity, and glare prevention, it is required to develop a light guide for controlling a light source of an LED lamp for a vehicle. For the development of the light guides, the development of machining technology that can cut micro patterns of hundreds of micrometers scale into surface roughness of tens of nanometers scale must be preceded. In this study, the effect of variations in cutting conditions on surface roughness was analyzed through experiments. The micro patterns was manufactured by cutting into STAVAX material, and the surface of the micro patterns was super-finished using a ball-shaped PCD (polycrystalline diamond) tool without flutes. In experiments, the cutting conditions of the super-finishing process were varied, and the varied cutting conditions were feed rate, radial depth of cut, and spindle speed

The purpose of using coolant in machining is both to increase a tool life and also to prevent product deformation and thus, stabilize the surface quality by lubricating and cooling the tool and the machining surface. However, a very small amount of cutting mist should be used because chlorine-based extreme pressure additives are used to generate environmental pollutants in the production process and cause occupational diseases of workers. In this study, medical titanium alloy (Ti-6Al-7Nb) was subjected to a processing experiment by selecting factors and levels affecting cutting power in the processing of the Aerosol Dry Lubrication (ADL) method using vegetable oil. The machining shape was a slot to sufficiently reflect the effect of the cutting depth. As for the measurement of cutting force, the trend of cutting characteristics was identified through complete factor analysis. The factors affecting the cutting force of ADL slot processing were identified using the reaction surface analysis method, and the characteristics of the cutting force according to the change in factor level were analyzed. As the cutting speed increased, the cutting force decreased and then increased again. The cutting force continued to increase as the feed speed increased. The increase in the cutting depth increased the cutting force more significantly than the increase in the cutting speed and the feed speed. Through the reaction surface analysis method, the regression equation for predicting cutting force was identified, and the optimal processing conditions were proposed. The cutting force was predicted from the secondary regression equation and compared with the experimental value.

Molds are actively used for mass production of products such as mobile phones. Molds are required to be durable and have a high level of surface roughness. Therefore, the optimization of mold processing is essential. In this study, the cutting processing of SDP20 steel used in molds was analyzed and optimized. This study is expected to contribute to the improvement of product productivity to which plastics are applied.

Recently, with the development of ultra-precision technology, the quality improvement of optical parts and various products is emerging. The need for a difficult-to-cut material that is light and exhibits high hardness and high strength physical properties is being emphasized. Ultra-precision machining processing solutions for these difficult-to-cut materials are being actively developed. In this research, experiments were performed using a DTM machine equipped with a laser-assisted machining module for ultra-precision machining of CaF2 materials that are brittle but exhibit high transmittance in a wide range from ultraviolet to infrared.

The Carbon Fiber Reinforced Plastic(CFRP) is used in many industrial areas owing to its excellent specific strength. In order to be utilized for machine parts, it is needed to have the hole drilling machining that presents the excellent surface. For the excellent hole machining of CFRP, this study evaluated the cutting force and remaining burr in accordance with changes in temperature by cooling down the temperature of the machining part. It could be used for other machining of composite materials produced by laminating fabric.

CNC cutting process has been mainly used for processing metal materials, and wood processing is also changing to machining by CNC machine. But the researches on the CNC machining of wood and its characteristics were rarely carried out. In this study, we analyzed the machined surface according to the cutting conditions such as the cutting direction, spindle speed, feed rate, cutting depth, chip removal in the CNC machining of wood. The consideration of cutting conditions and their effects on the surface finish will provide possibilities for improving the wood machining processes.