Evalutaion of chip breaker using flank wear

Abstract

Machining is a common and essential part of manufacturing of almost all metal products, and also or other materials like wood and plastic. In the today’s era of automatic machines optimization of machining operations is one of the key requirements. During turning operation, unbroken chips pose a major hindrance during machining and hence appropriate control of the chip shape becomes a very important task for maintaining reliable machining process. The continuous chip generated during turning operation deteriorates the workpiece precision and causes safety hazards for the operator. In particular, effective chip control is necessary for a CNC machine or automatic production system because any failure in chip control can cause the lowering in productivity and the worsening in operation due to frequent stop. Chip control in turning is difficult in the case of mild steel because chips are continuous. Thus the development of a chip breaker for mild steel is an important subject for the automation of turning operations. In this study, the role of different parameters like speed, feed and depth of cut, tool flank wear and chip breaker height and width are studied. In this study chip characteristics were tested for changing tool flank wear values. Response surface methodology was used to analyze the relationship between several explanatory variables and two predecided response variables. The chips obtained were found to have greater thickness at low feed and depth of cut, and gradually decreased as feed and depth of cut increases. The analysis lead to the conclusion that cutting speed and depth of cut are the most significant factors along with their higher order terms and interactions between variables.