Roughness and Hardness of 60/40 Cu-Zn Alloy
— The functional performance of machined components, often, depends on surface topography, hardness, nature of stress and strain induced on the surface, etc. Invariably, surfaces of metallic components obtained by turning, milling, etc., consist of irregularities such as machining marks are responsible for the above. Surface finishing/coating processes used to produce improved surface quality/textures are classified as chip-removal and chip-less processes. Burnishing is chip-less cold working process carried out to improve surface finish, hardness and resistance to fatigue and corrosion; not obtainable by other surface coating and surface treatment processes. It is a very simple, but effective method which improves surface characteristics and is reported to introduce compressive stresses. micro-irregularities start moving in the direction of the newly formed surface. The grain structure is condensed, producing a smoother and harder surface with superior load-carrying and wear-resistant capabilities. 2 + 0.0525X 4 + 0.0125X 1 X 4 − 0.02X X 4 − 0.0375X 3 X 4 Hv=160.625 − 2.37 5X 1 + 5.125X 2 + 1.875X 3 + 4.375X 4 − 1.625X 1 X 4 + 4.375X 2 X 4 − 2.375X 3 X 4 High surface microhardness (175H V ) was obtained at 400rpm, 2passes, 0.05mm/rev and 15kgf., and high surface finish (0.20µm) was achieved at 30kgf, 0.1mm/rev, 112rpm and single pass. In other words, surface finish improved by 350% and microhardness improved by 21% compared to as machined conditions.
A study on the surface characteristics of burnished components
Abstract Burnishing is a plastic deformation process in which the asperities of a machined surface are depressed to give a smooth and workhardened surface. In this paper, the development of a roller type burnishing tool is reported together with some experimental results concerning roughness and microhardness of surfaces of alloyed aluminium components.
Study of some aspects of burnishing
Burnishing is a plastic deformation process in which force is applied on to a metal surface through a hard roller or ball. In this paper, an attempt has been made to investigate the optimum burnishing force, change in dimension and the variations of tangential and normal forces in the process. Expressions were derived to calculate analytically the following: (i) optimum burnishing force, (ii) size change in burnishing. The accuracy of these expressions was verified by suitably conducted experiments. Five non-dimensional numbers of importance to burnishing were established. The variation of normal and tangential forces in roller burnishing (and so the coefficient of friction) was investigated experimentally.