It is known that reduced cutting speeds increase the limit of stability. However, this only applies to milling operations. In turning operations the stability limit initially drops with decreased cutting speed and subsequently rises with a further decrease in cutting speed. A minimum of attention is devoted to this phenomenon in the literature although many authors have noted the decline in the limits of stability during machining tests. In practice, it is important to know the conditions and extent of this decline. This paper summarizes previously published data and provides new data, measured by the authors of the paper. A comparison of the conditions used in the turning tests shows that the decline in the limits of stability and its subsequent increase in the area of lower cutting speed only occur when using a tool with a small clearance angle. A new analysis of the previously published data from the measurement of dynamic cutting force coefficients revealed that the drop in the stability is affected by changing the mutual phase of the dynamic cutting forces and tool vibration.
Science Journal 