Rekayasa Mesin (May 2019)
Studies the Cold Cooling using Bio-Nanofluids, Characteristics and Applications in Milling Operations on High-Hardness Steels
Abstract
The cooling system has an important role in the quality of machining results, the cooling fluid (air/fluid) are developed to be able to reduce heat and friction arising from the formation of the product, but also environment-friendly. The use of natural oils has been tested in various machining conditions with a minimum quantity lubrications (MQL) method, including the addition of materials that can improve fluid convective properties. Cooling performance with natural materials results in surface roughness according to product smoothness requirements according to ASTM classification and is able to maintain a low tool temperature and reduce chatter/tools vibration. Improvement of the MQL process, temperature, and compressed air pressure conditions determine cooling performance, the lower the compressed air temperature will increase the fluid's ability to reduce tool temperature and increase durability and tool life. The process of forming steel with high hardness requires a cooling system with special conditions. The properties of natural oils will be enhanced by the convective thermophysical properties by the addition of Titanium Oxide (TiO2), CuO and Aluminum Oxide (AL2O3). Natural oils used in the study are corn oil, sunflower oil, water with the addition of nanoparticles. The formation of nanofluids uses magnetic stirrer with varying time and rotation speed, and % weight ratio. The MQL System is equipped with cold air from the compressor which is cooled by utilizing the evaporation/refrigeration process which is kept constant at 10oC. The cooling system is equipped with a microcontroller/interface to keep the air temperature/pressure constant. In this paper the data presented is a study of cooling in the hard milling process to determine the most nanofluid/dominant factors that affect the results. The results showed that the use of cutting fluids reinforced by nanoparticles in natural oils in a minimum amount increased lubrication properties. There is a significant effect on the use of cooling fluid types with surface roughness, fluids with high lubrication properties, significant to reduce surface roughness, cutting temperature and power consumption. The nanofluid prove was able to apply in an environment-friendly manufacturing process very promising.
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