Prediction of Chip Morphology in Orthogonal Machining Processes
 
 

Praveen D. Rao | MS | 1997

ABSTRACT:

Chip control research has received significant interest in the modern automated metal cutting industries. Chip control in metal machining involves design of chip handlers to dispose chips quickly and efficiently from the machining area. Due to the increase in pressure from consumers and environmental agencies, metal cutting industries have been forced to reduce their waste streams. Cutting fluid, along with the chips, constitute a major portion of the waste stream. One way to reduce this waste stream is by reducing or eliminating the use of cutting fluids. This technique is often called dry machining. However, cutting fluid is believed to play an important role in chip morphology and flushing the chips out of the machining area. Hence before elimination of cutting fluids from the metal cutting system, there is a good need to understand the effects of process parameters (speed, feed, toolgeometry, work material etc.) on chip morphology (chip curvature, and breakage) is believed to play an important role in the design of cutting tools.

Although the long term goal is to predict chip curvature in complex machining processes such as drilling, in this research work a mechanistic model has been proposed to predict chip curvature based on stream line theory in a simple process of orthogonal machining. In conventional chip curvature models, the effect of cutting speed on the chip curvature has not been fully understood. One of the salient features of this work is the inclusion of cutting speed in the model. A set of statistically designed experiments were used to validate the model and the results show good agreement. Further, a model for chip breakage is also presented along with a finite element analysis to demonstrate where the chip breaks during orthogonal cutting. A high speed video analysis is also presented to better understand the life cycle of an orthogonal chip. Finally, conclusions on the research findings are given along with recommendations for future work that can be done in this area.

If you have any comments or suggestions please e-mail jwsuther@mtu.edu.