Surface roughness:
In definite practice, surface roughness based on several parameters such like; cutting parameters (V, f, d), cutting fluid, cutting tool geometry, workpiece material properties and vibration throughout cutting. Cutting speed also influence surface roughness value based upon the kind of material being machined. Relationship among cutting speed and height of micro irregularities follows the curve 'a' of Figure 14 throughout machining of a general material as steel, Whereas curve 'b' throughout machining of comparatively brittle material as brass, C. I., non-ferrous metals and high alloys steels.
The primary hump in curve 'a' of Figure 14 is described with the help of making up of BUE that is maximum at cutting speed V2. Beyond this point, the size of BUE begins reducing due to rise in temperature and almost it disappears at cutting speed V3. Although, microirregularities height keeps reducing until cutting speed V4 is attained, beyond that the cutting procedure stabilizes and also the height of microirregularities.
The reduction between V3 to V4 has been described [Arshinov and Alekseev, 1976] on the basis of reduction in friction.
In case of curve 'b' due to the absence of BUE, the height of the irregularities continually keeps reducing before it becomes constant practically.