Analytical and Experimental Investigation of Contribution of Burnished Parameters on Roughness and Micro Hardness of AA6351

ABSTRACT Burnishing is a surface enhancement process in which plastic deformation of surface induces compressive residual stresses. It is a cold working chip less process in which material is pressed against burnishing force or pressure. By imparting compressive stresses in the surface layer, the tensile range on the component surface was reduced. From the literature it is viewed that several methods are available for inducing compressive residual stresses on component surface layer to improve mechanical properties of metal and alloys. Ball burnishing is one of the method for surface enhancement and with the effective burnishing parameter the surface finish and micro hardness of the metals or alloys gets improved. The test will carried out for AA6351 alloy material, 0.10 % Cu, 0.4-1.0% Mn , 0.6 % Fe , 0.4-1.2 % Mg, 0.6-1.3 % Si and reminder is Al. The material having mechanical properties as T.S. =150-160Mpa.This AA6351 alloy is widely used in aerospace industry as well as marine industry. In this work attention is given toward a design such a tool which is suitable for burnishing operation of conventional lathe machine. The ball burnishing tool is manufactured with hard steel ball. The experimental work has been carried out considering suitable burnishing parameters as feed (mm/rev), speed (rpm), depth of penetration (mm) and number of tool passes. Keeping rest parameters constant. The kerosene is used as coolant. In this work ball burnishing process will carried out on specimens as per experimental matrix with burnishing input parameters as feed, speed, depth and number of tool passes on conventional lathe machine. After experimentation the results will be obtained for surface roughness and micro hardness for each specimen. From the experimental results as per experimental matrix the ANOVA and regression analysis will carried out to find out contribution of burnishing parameter for surface roughness and improvement in micro hardness properties of AA6351 alloy. Then the microscopic examination will be done to analysis the effect on microstructure of AA6351. The maximum contribution of burnishing parameter will be investigated for further burnishing operation which will give best mechanical properties for alloys.