Experimental Analysis of External Roller-Burnishing On the Surface Roughness, Surface Hardness and Microstructre of Brass and Aluminium

Surface finish is a critical factor in creating a durable metal component. Manufacturers strive to produce metal surfaces free of scratches, nicks and gouges, since such defects make components vulnerable to damaging cracks. A smooth surface alone is insufficient, however, to protect the component against the wear and tear of regular usage. Machining process such as milling, turning produce a surface with inherent irregularities. Finishing process such as grinding, lapping, honing, polishing & buffing commonly seeing employed to improve the surface finish.

Unlike the above mentioned traditional methods that depend on the chip removal, hard Roller burnishing is a cost effective surface enhancement process in which a smooth hard tool (using sufficient pressure) is rubbed on the metal surface. This process flattens the roughness peaks by causing plastic flow of the metal. A process of finishing by surface plastic deformation can meet this requirement. It not only improves surface finish but also imposes favorable compressive residual stresses and raises hardness in functional surfaces, which can lead to long fatigue life.

Both internal and external surfaces can be burnished using an appropriate tool. Burnishing improves the surface finish, surface hardness, wear-resistance, fatigue life and corrosion resistance. In this work an attempt has been made to analyze the surface finish of NON-FERROUS materials (Ex. Brass and Aluminium), by external roller burnishing process under different speeds, and depth of cuts at number of passes.