Effect of morphological evolution of serrated chips on surface formation during high speed cutting Ti6Al4V

Ti6Al4V alloys are widely used in aerospace industry due to its excellent mechanical properties, however, serrated chips are easily formed in high speed cutting and have great influence on the surface formation process. In this study, high speed cutting experiments and simulations ranging from 125-750m/min are conducted to explore the characteristics of serrated chips and surface quality. Accordingly, the evolution of serrated chips characteristics and its effect on cutting force and machined surface are discussed. The results show that the inhomogeneous plastic deformation of serrated chips directly causes the cutting forces fluctuation and then leads to the microwaves of machined surface. Furthermore, the surface toughness reaches the highest around 250 m/min and then decrease with the increase of cutting speed, meanwhile, as for the surface defect dimples, their shapes get equiaxed and sizes become small, which shows that the surface quality is improved by increasing the cutting speed. Therefore, surface quality could be controlled by optimizing cutting parameters with better understanding of the influence of chips evolution on machined surface quality.