Control of Chips in the Turning of 4150 by Using an Obstruction Type Chip Breaker

Abstract

This paper provides the optimal ratio of feed to the chip breaker location in the machining of 4150 steel when using an obstruction type chip breaker. The objective was to generate properly broken chips (half-turn or two thirds turn) avoiding over-broken and long chips. A set of oblique machining tests were performed on a LeBlond lathe with a carbide insert of 15 deg. edge and side clearance angles and −5 deg. rake angle. The radii of chips were measured by comparing a wide number of diameters and then finding the mean. The results were analyzed by plotting the chip radii versus nondimensional ratio of feed and chip breaker location. A brief theoretical consideration on the phenomena is also given. The experimental result well agrees qualitatively with the theoretical analysis. A very effective range was found with the optimal value of the ratio being about 20.