Modeling and Optimization of Vibration Amplitude in Turning of Stainless Steel AISI 304 at Various Tool Overhangs

Chatter is detrimental to all machining operations. In metal turning operations it leads to inferior surface topography, reduced productivity, and shortened tool life. Various researchers have thus tried to develop mathematical models and theories for chatter formation in order to find optimum ways of chatter suppression. This research investigated the chatter phenomenon in turning of stainless steel AISI 403 in the light of vibration amplitude. Central composite rotatable design of experiments under Response Surface Methodology (RSM) was employed to create a second order mathematical model, and the adequacy of the model was verified using analysis of variance (ANOVA). Machining operations were carried out on a conventional engine lathe (Harrison M390, England) with rated power of 5.5 kW and maximum spindle speed of 2000 rpm. Cemented Tungsten Carbide (WC-Co) inserts were used to machine a stainless steel cylinder. The data acquisition system consisted of a vibration sensor (KISTLER accelerometer Type 8774A50) and a signal conditioning unit, which was connected to the computer via a data acquisition (DAQ) card. Analog input signals were fed into the DAQ card and evaluated using the DASYLab 5.6 software. The vibration results were analyzed in the frequency domain (FFT) plots. It was observed that the uncontrolled vibration of the tool holder was the largest contributor to chatter formation.