Metal Cutting Experiment

INTRODUCTION:

Research in metal cutting was started with Cocquilhat in 1851 which measured the work required to remove a given volume of material in drilling. The attempt made by Time led to the explanation of formation of chips in 1870 and further research was made by Tresca in 1873. Later in 1881, Mallock suggested that the cutting process was the shearing of workpiece to form the chip and emphasized the importance of the effect of friction occurring on the cutting tool face as the chip was removed. Further, Taylor investigated the effect of tool material and cutting conditions on tool life during rough operations. Latest fundamental work has been carried out by Ernst and Merchant in 1941 dealing with the mechanics of metal cutting process.

et al. [6] presented an experimented setup for the measurement of temperature field in high speed machining. Their paper presented an experimental setup during an orthogonal machining operation with 42 CrMo 4 steel. The technique of temperature measurement was developed on the principle of pyrometer in the visible spectral range by using an intensified CCD camera with very short exposure time and interference filter at 0.8 micrometer. They obtained the temperature gradients in an area close to the cutting edge of the tool, along the secondary shear zone. It was established that their experimental arrangement shown in figure was quite efficient and can provide fundamental data on the temperature field in material during orthogonal high speed machining. They showed experimentally that, for a cutting speed of 20 m/s a hot spot was located near the tool-chip interface at a distance of 300-350 μm of the tool tip. This value corresponds to about the two-thirds of the depth of cut. The reaching temperature is around 825°C. The temperature in the chip increases with increasing of the cutting speed. Their result showed that, with an increase of the cutting speed from 20–30 m/s the dependence of the temperature on the cutting speed was more noticeable. They even showed that, the temperature appeared to stabilize for the cutting speeds larger than 40 m/s. A similar tendency was observed with the increasing in the depth of cut and for a cutting speed fixed to 40 m/s by their experimental technique. The temperature in the chip was nearing a saturated value about of 840°C during the process of an un-deformed chip thickness larger than 0.5