A composite tool for ball endmilling

The paper reports on the performance of a novel composite ball nose endmill that utilizes cermet and tungsten carbide indexable inserts on the same cutter body, with a view to optimizing both tool life and workpiece surface roughness. The technique exploits the asymmetric design of the cutter to position the cermet and tungsten carbide inserts appropriately, so that their characteristic tribological attributes are consistent with the functions of surface generation and wear resistance. Experimental work on ball endmilling of hardened AISI H13 tool steel is presented to illustrate the concept. The mechanism of performance enhancement of the composite tool is also detailed with reference to the flank wear pattern of the inserts and the morphology of the machined surface.