Comparative study on the cutting performance of self-propelled rotary cutters and indexable cutters in milling TC11 titanium alloy

Abstract

Titanium alloy, with superior mechanical properties, is widely used to manufacture key parts in the aerospace industry. Nonetheless, there exist some problems in machining titanium alloy, such as low machining efficiency, serious tool wear, and difficulty to guarantee the surface quality. In this paper, the comparative experimental study is conducted on milling the titanium alloy TC11 with indexable milling cutters and self-propelled rotary milling ones, and the wear process of the two types of cutters is explored to have found how the milling force, chip micro-morphology, and machined surface quality of theirs vary according to milling length. The experimental results indicate that compared with indexable milling cutters, self-propelled rotary milling cutters show relatively minor and slowly increasing cutting forces. Moreover, self-propelled rotary milling cutters show better wear resistance; that is, the flank wear is more evenly distributed along the cutting edge and the wear rate is slower. The two types of cutters both produce serrated chips, but the curling degree of the chips produced by self-propelled rotary milling cutters is comparatively larger than that by indexable milling cutters, and with the increase of milling length, the former produces more regular chip morphology and evener sawtooth distribution. When the cutting edge wear is slight, the machined surface quality by the two types of cutters does not differ a lot. However, with the increase of the milling length, the wear of indexable milling cutters becomes increasingly serious, and the machined surface quality by it becomes a lot worse as some defects occur such as holes and tearing on the workpiece surface. In comparison, the surface roughness of self-propelled rotary milling cutters get worsen slowly.