Experimental study of surface roughness and burr width in micromilling of titanium alloy

Micromilling is a machining process in manufacturing of the miniature parts. Because of high oxidation and corrosion resistance, high fatigue strength and application of Ti6Al4V in hi-tech industries, in this paper surface roughness and burr formation in micromilling of this alloy have been investigated. Cutting parameters including spindle speed, feed rate and axial depth of cuthave been considered as input parameters of tests. Experiments have been performed for two cases: a) in presence of the minimum quantity lubrication and b) wet conditions. Carbide micro-end mill tool of diameter 0.5 mm and TiAlN coating was used. The Taguchi experimental design method has been used to design and analysis of results. Results showed that the spindle speed and feed rate were the most effective parameters on the surface roughness and burr width of titanium alloy, respectively. Also, by increasing both of these parameters, surface roughness and burr width were decreased. In addition, application of minimum quantity lubrication technique significantly improved the surface quality, and it was more effective in upper levels of spindle speed and axial depth of cut. Finally, the best surface quality was attained in spindle speed of 30000 rpm, feed rate of 0.8 μm/tooth and cutting depth of 60 μm.