The effects of cutting temprature and thermal fatique factors on tool wears in face milling operations

The recent cutting tool technology improves the capability of machining of wide range materials with the high cutting speed and the feed rates. Improving the cutting conditions and to reach maximum tool life will be always up to date, since the cutting tool economy and environmental sensitivity has growing importance.In this thesis, the effects of cutting temperature on the thermal cracks and tool wears are evaluated in face milling operations according to cutting parameters. The experimental studies are carried out with the cutting parameters including, the cutting speeds (100, 110, 120, 130 m/min), the feed rates (0,05 ? 0,075 ? 0,1 mm/teeth), the cutting depths (1,25 ? 2 mm) and dry/wet coolant conditions. Kistler 9257B dynamometer is used for measuring the cutting forces. The cutting temperatures, the surface roughness measured and tool wears are investigated. During the chip removal thermocouple which are embedded in the workpiece is used to measure the cutting temperature. According to experimental results, the cutting temperatures are increased while cutting speeds are increasing. The temperature is also increased with the inclined metal removal rate that depends on the feed rate and the cutting depth. In addition to flank wear, some inspection has been carried out with scanning electron microscope for the tool deteriorations. It is concluded that thermal cracks, mechanical fracture on tool face, some chipping, flaking, flank wears and plastic deformations has been occurred.