Application of the response surface methodology in the ball burnishing process for the prediction and analysis of surface hardness of the aluminum alloy AA 7075

In this study, AA 7075 aluminum alloy has been burnished using different burnishing parameters such as burnishing force, number of passes, feed rate and burnishing speed with a ball burnishing apparatus. Burnishing parameters, which affect the surface hardness, were examined using response surface methodology with rotatable central composite design and analysis of variance. Using the experimental results, a regression model has been developed to predict surface hardness. The statistical analysis showed that, burnishing force and number of passes have the most significant effect on surface hardness. These results, which were obtained from the regression model, are highly consistent with the experiments. The absolute average error between the experimental and predicted values for surface hardness was calculated as 2.79 %. The results of our study show that response surface methodology is a suitable technique that can be efficiently used to predict surface hardness in ball burnishing process.