Evaluation of the microstructure and tensile strength of SiC reinforced AA1050 aluminum composite wires fabricated by friction stir extrusion process

Abstract

In this study, the friction stir extrusion process as a new method was used to produce AA 1050 aluminum composite wires reinforced with silicon carbide (SiC) powder. The effect of process parameters on temperature (T), porosity (P) and ultimate tensile strength (UTS) was evaluated using the response surface method based on the Box-Behnken design. The input parameters included rotational speed (RS), extrusion force (EF) and reinforcement weight percentage (RF). Moreover, the microstructural evaluation of composite samples was conducted using optical microscope and scanning electron microscope. Finally, analysis of variance and regression analysis were used to obtain an appropriate model and confirm the accuracy of the results. The results showed that the temperature was increased by increasing the rotational speed to 1000 r/min and decreasing the extrusion force to 5.5 kN. Moreover, the lowest porosity value (averaged = 0.5%), and the highest tensile strength value (averaged = 153 MPa) were obtained at RS = 750 r/min, EF = 10.5 kN and RF = 3%. This can be attributed to the uniform distribution of reinforcing particles and strong interfacial bonding between SiC particles and the aluminum matrix. Also, the most effective parameter in the process was rotational speed which exhibited the greatest influence on P (53%) and UTS (41%) of composite samples. However, reinforcement weight percentage had the least effect on P (14%) and UTS (28%).