EFFECTS OF CUTTING SPEED AND FEED RATE ON THE SURFACE CHARACTERISTICS OF SOME METALS DURING CYLINDRICAL MACHINING

Abstract

In order to establish, the pattern of surface characteristics against some input machining variables: this study was carried out on the effects of cutting speed and feed rate during turning process on the surface characteristic of three different metals aluminum, brass and mild steel. The cutting force decreased from 6700N to 5900N when the cutting speed increased from 3.20m/s to 7.50m/s. Correspondingly, the surface friction co-efficient decreased from 0.358 to 0.236. The cutting force increased with increase in feed rate with corresponding increase in co-efficient of friction. The increase in cutting force with increased federate simply implies that machinability decreases with feed rate in the order aluminum, brass and mild steel. The corresponding increase in co-efficient of friction with increasing feed rate implies that surface roughness increased with feed rate. Co-efficient of friction and cutting force both decreased when cutting speed is increased leading to decrease in surface roughness. It is concluded that a high cutting speed combined with lower feedrate will produce a smooth surface finish and also physical property of material such as hardness affects the response of material to machining operation.