(Dr. Ye-Hwa Chen, advisor)
"The Prediction of Chatter Stability Considering Flank Wear and Non-linearity in Machining of Hardened 52100 Steel"
In spite of a large demand from industry, a realistic model for hard turning has not been developed yet. This study attempts to develop a chatter model for predicting the stability in machining of hardened 52100 steel. The salient features of this chatter model include the consideration of the effects of flank wear and non-linearity. In a preliminary study, a linear model has been developed, which considers the flank wear effect through non-uniform load distribution on a tool tip. A stability analysis based on the root locus method is conducted to determine a critical stability parameter. A series of experiment has been carried out to determine stability limits as well as certain characteristic parameters of the system. According to the experimental results, the critical width of cut increased very rapidly when the spindle speed is higher than 12 rev/sec. Comparing with experimental data, predicted chatter stability is in a good agreement except in the very low and the high speed range. An empirical model is proposed to fit in with the experimental stability limits in the full range of the spindle speed. With these prior research results, interim conclusions and future research plans are suggested.