Process parameters optimization of friction stir processed Al 1050 aluminum alloy by response surface methodology (RSM)

Aluminum alloys are extensively used in many applications such as aerospace and defense industries because of the high strength-to weight ratio and good ductility. Friction stir processing (FSP) is a technique based on the principle of friction stir welding (FSW) to improve the mechanical properties. This work presents the formulation of a mathematical model with process parameters (rotational speed, feed rate, number of passes and tool shape) to predict the response or the mechanical properties of friction stir processed of 1050 aluminum alloy (yield strength, ultimate tensile strength, percentage elongation and microhardness). A central composite design with four factor, each factor with five levels was used and a response surface methodology was applied to develop the regression models to predict the responses. Method of analysis of variance ANOVA was applied to figureout the significant process parameters that have effect on the responses. These results point out that the friction stir processing of 1050 aluminum alloy with 1500 rpm rotational speed, 116 mm m(-1) feed rate, 3 FSP passes and square tool shape, have the maximum predicted responses using response surface methodology (RSM).