Application of factorial design for studying the burr behaviour during face milling of motor engine blocks

This paper studies the behaviour of the burrs’ geometries generated during face milling of motor engine blocks. Ceramic and PCBN inserts mounted on a milling cutter with 160 mm of diameter and capacity for 22 inserts, 18 of them for roughing and 4 for finishing, were used. During the tests the cutting speed, the feed rate, the depth of cut and the flank wear were varied. The burr was measured in nine different positions of the edge of the workpiece, varying thus the tool exit angle. It was verified that the burr height was smaller when using PCBN than ceramic inserts. The wear and the tool exit angle had significant influences on the burr size. The greater the flank wear and the exit angle, the bigger the burr. The burr sizes were reduced with increasing the feed rate and in some cases with the depth of cut, but increases when the cutting speed was enhanced.