| Summary: | 碩士 === 國立中興大學 === 機械工程學系所 === 96 === Cutting process is one of the basic manufacturing processes. As the machining techniques and equipments progress with technology, the precision of cutting process is also improved substantially. Among other factors affecting the precision, the cutting force and temperature of workpiece, which affect the deformation of workpiece, play important roles. This research is aimed to investigate the effects of cutting speed, chip load and depth of cut on the cutting force and temperature of workpiece and their correlation with the 6061T6 aluminum alloy, a common alloy used in industry. In this study, the cutting force and temperature of workpiece were analyzed by theoretical models first. A series of experiments exploring the above effects were then planed and conducted. The cutting force and temperature of workpiece during milling were measured via a dynamometer and thermal couples. The result shows that the specific cutting force is lower with higher cutting speed and larger depth of cut while only slightly influenced by the chip load. This dimension effect is similar to the observations of previous researches. The result also shows the temperature of workpiece is lower with the increasing of cutting speed and with the decrease of depth of cut. It also slightly decreases as the chip load increases. A model, C．Ts(V．t / (6.21x10-5))n, was built with measured data to describe the average temperature near the shear surface. In the model Ts is the calculated temperature of shear face and the coefficient C and exponent n depend on the depth of cut and chip load. The study also shows that the cutting force and the increase of workpiece temperature are highly correlated. With the same chip load, both cutting force and the increase of workpiece temperature are proportional to the depth of cut but slightly in inverse proportion to the cutting speed. Under the same depth of cut, the cutting force is proportional to the chip load, but the rising of workpiece temperature is in inverse proportion to the chip load.
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