Burr height minimization using the response surface methodology in milling of PH 13-8 Mo stainless steel

Abstract

Burrs formed during the machining process is considered a major problem in the manufacturing industry because they can impair mechanical assemblies, change the dimensions of the machined products, and compromise the physical integrity of the operators, among many other inconveniences. Therefore, burrs should be avoided but if formed their dimensions should be minimized. In this work, the burr dimensions were investigated, and the cutting conditions that minimize them were determined using a central composite design (CCD) and response surface methodology (RSM) in face milling of PH 13-8 Mo stainless steel with coated carbide inserts. Burr formed on the workpiece exit edge and the behaviors of its height during the manipulation of the evaluated variables (tool exit angle from the workpiece, cutting speed, feed per tooth, axial depth of cut and average tool flank wear) were analyzed. The burrs were indirectly measured, where replicas of the workpiece edges (with their burrs) were produced with condensed silicone. The results showed that there is a considerable reduction in the burr height when lower exit angles and new cutting tools are used. The minimum number of burrs is produced when using increasing feed per tooth and decreasing axial depth of cut. The cutting speed presented negligible influence on the height of the burr.