Experimental Investigation of Chatter Trends in Titanium End Milling

The occurrence of chatter vibrations which mainly originate as result of lack of rigidity in machine parts, cutting tool and instability of the tool-workpiece system during machining is still a recurring concern in the manufacturing industry, especially in the processing of titanium alloys. These vibrations have a detrimental effect on tool performance and product quality. Therefore, this research presents an experimental determination of chatter trends during a Ti-6Al-4 V end-milling process, with a focus on the maximum two-dimensional (2D, X and Y plane) displacements of the workpiece. The effect of three factors namely: spindle speed (1000-2000 rpm), feed rate (250-350 mm/min) and depth of cut (0.3-0.9 mm) were investigated using a vertical MV204II/10 CNC end-milling machine. Data was collected using an accelerometer and analyzed in order to examine the statistical significance of each parameter on the developed chatter regression model. The results showed that larger displacement values were obtained at settings of depth of cut of 0.9 mm, feed rate of 350 mm/min and spindle speed of 2000 rpm in the Y-axial direction of the machine tool. Lower surface roughness was achieved at low depth of cut of 0.3 mm, low feed rate of 250 mm/min and spindle speed of 2000 rpm in the direction of the feed. The regression model showed that effective control of the stability of the process and was achieved at lower values of the investigated parameter combinations.