Examination of the Change in Surface Micro-Hardness of Burnished Aluminium Alloy Components

Abstract

The life and reliability of machine components or elements are effected greatly by the surface integrity. Machined surfaces by conventional processes such as turning and milling have inherent irregularities and defects like tool marks and scratches that cause energy dissipation (friction) and surface damage (wear). Burnishing processing is a kind of chip-less processing which improve the surface integrity obviously. To expand the application of the processing, the method of reliability assessment of burnishing processing was investigated experimentally in this paper. Parameters influencing the mechanical properties of the surface layer include burnishing feed, speed, force, number of passes, material of the workpiece, geometry of the burnishing tool and application of lubricant. Three parameters of them were considered namely: number of passes (i), feed rate (f) and force (F). For plan and execute the experiments we used the Taguchi type full factorial experimental design method by which empirical formulas can be created easily. The measurement of the surface micro-hardness was executed with Wilson Instruments Tukon 2100B measuring equipment. The measured results were evaluated by the comparison of a special correlation formula to determine the optimal combination level of the different parameters in the given interval.